The Best Gut-Friendly Supplements for Brain Fog, Focus, and Mood During Intermittent Fasting (16:8 Friendly)

If you’re doing intermittent fasting (especially the 16:8 method) and you struggle with brain fog, low energy, poor memory, or mood dips—you’re not alone.

But here’s the good news: there are supplements you can take during your fast that support brain power, improve focus, boost your mood—and won’t break your fast. Even better? These options are gentle on your stomach, so they’re safe for people with gastritis or sensitive digestion.

Intermittent Fasting and Cognitive Challenges: Time-restricted feeding (such as 16:8 fasting) can yield health benefits but may also lead to brain fog, low energy, or sluggish focus, especially during the fasting window. Many people report difficulty concentrating, fatigue, or mild mood changes when fastingwhynotnatural.com. The good news is that certain supplements can support mental clarity, memory, verbal fluency, and mood without breaking your fast (i.e. without calories or insulin spikes). However, for those with gastritis or sensitive stomachs, it’s crucial to choose gut-friendly options and avoid irritants. Below is a structured guide to fasting-safe supplements, typical dosages, and precautions for cognitive and mood support.

Fasting & Gastritis Considerations

• Fast-Safe = No Calories: In fasting, calories (especially carbs/protein) disrupt the metabolic fasting state. All supplements listed here are calorie-free or negligible in calories, so they won’t spike insulin or stop ketosiswhynotnatural.com. (Be wary of gummies or syrups with sugar, which would break a fastwhynotnatural.com.)

• Empty Stomach Tolerance: With gastritis, the stomach lining is sensitive. Even calorie-free supplements can irritate some people’s stomach if taken without food. We focus on options that are generally well-tolerated on an empty stomach. If you have active gastritis, introduce one supplement at a time and monitor tolerance.

• Avoid Irritants: Steer clear of acidic or harsh supplements during the fast. For example, apple cider vinegar, high-dose ascorbic acid (vitamin C), or coffee on an empty stomach can aggravate gastritis due to acidity. Likewise, certain herbal pills like ashwagandha can worsen gastritis if taken alone with watervananherbal.eu. These are better reserved for the eating window (if at all).

• Medication Interactions: If you take medications (for blood pressure, thyroid, MAOIs, etc.), check for any interactions with these supplements. Although generally safe, it’s wise to consult a healthcare provider when adding supplements, especially with underlying conditions.

With these cautions in mind, below are key supplements that many intermittent fasters use to stay sharp and energized. Each is fast-compatible (no or near-zero calories) and has notes on gut-friendliness, benefits, dosage, and precautions.

Fast?Safe Cognitive Support Supplements

Caffeine (Coffee/Tea or Caffeine Pills)

Benefits: Caffeine is a well-studied stimulant that improves alertness, energy, and mood by stimulating the central nervous systemmemphis.edu. Many fasters use black coffee or tea in the morning to clear brain fog and boost focus. Combining caffeine with L-theanine (see below) can further enhance focus and reaction time while smoothing out jittersmemphis.edu.

Fast-Safe?: Yes – plain black coffee or tea has virtually no calories (~2 kcal) and does not break a fast. Caffeine pills are also calorie-free. However, use moderation: standard safe intake is up to ~400 mg caffeine per day (roughly 2–3 cups of coffee)memphis.edu. Excess caffeine won’t add calories, but it can trigger stress hormones.

Gut Considerations: Use caution with gastritis. Caffeine can increase stomach acid and may irritate an empty stomach, potentially worsening heartburn or pain. If you have gastritis, consider low-acid coffee (cold brew or acid-reduced beans) and avoid drinking it scalding hot. Alternatively, a caffeine pill with water might reduce direct stomach acid exposure (but caffeine itself still prompts acid release). Listen to your body – if even small doses cause discomfort, you may need to skip caffeine during the fasting window.

Typical Dosage: 50–200 mg in the morning is common for cognitive boost. This could be ~1 cup of coffee (~95 mg) or a caffeine tablet (100–200 mg). Start low (e.g. 50–100 mg) if you’re sensitive. The effect peaks within an hour and lasts a few hoursmemphis.edu. Avoid dosing late in the day to prevent insomnia (half-life ~5 hours).

Precautions: Caffeine is addictive; abrupt cessation can cause headaches or fatigue. High doses may cause jitters, anxiety, elevated heart rate, or an energy “crash” latermemphis.edumemphis.edu. It’s generally safe for healthy adults, but those with heart conditions or anxiety disorders should use minimal amounts or avoid. Ensure you stay hydrated, as caffeine is mildly diuretic. If you experience stomach pain, nausea, or palpitations, reduce the dose.

L-Theanine

Benefits: L-theanine is an amino acid from tea leaves known for inducing a state of “calm focus” without sedation. It promotes relaxation and reduces anxiety while actually improving attention and reaction timesciencedirect.com. In healthy adults, L-theanine supplementation has been shown to enhance verbal fluency and executive function after several weekspmc.ncbi.nlm.nih.gov. It synergizes with caffeine – many studies find that caffeine+theanine together improve mood, focus, and cognitive performance better than caffeine alonememphis.edu. In short, L-theanine can take the “edge” off caffeine (less jitteriness) while supporting alertness and mental clarity. This makes it popular for fasting individuals who want steady focus.

Fast-Safe?: Yes – 100% calorie-free. L-theanine is usually taken in pill or capsule form (or as a tea, but tea has minimal calories). It does not raise blood sugar or insulin.

Gut Considerations: Generally gentle on the stomach. L-theanine is not acidic or harsh, and studies have found even 400 mg/day was well-tolerated with no significant adverse effectsalzdiscovery.orgalzdiscovery.org. It’s one of the easier supplements on an empty stomach. Rarely, very high doses might cause mild drowsiness or lower blood pressure, so those with low BP should be mindfulalzdiscovery.org. Overall, it’s considered safe for gastritis sufferers, and even has stress-reducing benefits that may indirectly help gut health by lowering anxiety. Green tea itself can irritate some stomachs due to tannins, but purified L-theanine doesn’t have that issue.

Typical Dosage: 100–200 mg during fasting for cognitive benefits is common. 100 mg is often paired with a cup of coffee (~100 mg caffeine) for a balanced nootropic effect. Doses up to 200–400 mg are used for anxiety reduction or sleep quality (higher doses can promote relaxation). For daytime focus, 100–200 mg is usually sufficient. Onset is within 30–60 minutes. If taken in capsule form, swallow with water. If using tea as a source, note the L-theanine content in tea is lower (~5–20 mg per cupalzdiscovery.org) so a supplement ensures a consistent effective dose.

Precautions: L-theanine is very safe; it’s classified as GRAS (Generally Recognized As Safe). Side effects are rare. A small fraction of users report headache or slight dizziness at high doses. It can mildly lower blood pressurealzdiscovery.org, so if you are on antihypertensive medication, use caution and monitor blood pressure. Because it has calming properties, very high amounts might cause sedation in some (though usually it’s non-drowsy). There are no known serious interactions, but as always, pregnant or breastfeeding individuals should consult a doctor before use. Combining L-theanine with caffeine is considered safe – in fact, L-theanine may reduce blood pressure spikes caused by caffeinealzdiscovery.org.

Creatine Monohydrate

Benefits: Creatine is a compound best known for muscle energy, but it also supports brain energy metabolism. It helps regenerate ATP (cellular energy currency) in both muscles and the brain. Research shows creatine can bolster cognitive function when the brain is under stress (e.g. sleep deprivation or intense mental tasks)pmc.ncbi.nlm.nih.gov. By increasing energy reserves in brain cells, creatine may improve mental fatigue, processing speed, and working memory in challenging conditionspmc.ncbi.nlm.nih.govnature.com. Many people doing IF include creatine to combat the “afternoon slump” or general fatigue. It’s also been reported to lift brain fog in scenarios like sleep losslivemomentous.com. Beyond cognition, creatine supports physical energy and strength, which can indirectly improve mood and vitality during fasting. Notably, creatine is an osmotically active amino acid derivative, so it helps hydrate muscle and nerve cells by drawing in water.

Fast-Safe?: Yes – creatine contains no usable calories and does not spike insulinwhynotnatural.com. It’s an amino acid compound, but unlike protein or BCAAs, it doesn’t activate mTOR growth pathways during fastingwhynotnatural.com. Taking creatine will not break ketosis or autophagy in any significant way. It dissolves in water; just avoid any creatine drinks that have added sugars. Pure creatine powder or capsules are fine.

Gut Considerations: Generally safe on an empty stomach, but a few tips: Use plenty of water and moderate doses to avoid minor GI upset. Some people experience a bit of stomach cramping or diarrhea if they take a large dose (e.g. 10+ grams at once) without enough water. The typical maintenance dose (3–5 g) is small and usually well-tolerated. If you have a very sensitive stomach, you can split the dose (e.g. 2–3 g morning, 2 g later) to minimize any bloating. Creatine monohydrate is slightly grainy – ensure it dissolves fully in water before consuming, as undissolved powder could cause irritation. There are buffered or micronized creatine forms that some find easier on the gut, but plain monohydrate works for most. Importantly, creatine is not acidic or NSAID-like, so it does not irritate the stomach lining in the way that, say, aspirin would. It’s considered stomach-friendly for gastritis patients in normal doses, but stay well-hydrated; dehydration can concentrate stomach acid and cause discomfort.

Typical Dosage: 3–5 grams per day is the standard dose for cognitive and physical benefitswhynotnatural.com. This can be taken during the fasting window (e.g. morning) mixed in a glass of water. No need for a “loading phase” unless you want faster saturation; even then, loading (20 g/day in 4 doses) might cause more GI upset, so it’s not recommended for sensitive individuals. Consistency is key – daily use keeps muscle and brain creatine stores topped up. Creatine has no acute stimulant effect; instead, it gradually improves cellular energy over days to weeks. Some people choose to take it post-workout or with their first meal for habit’s sake, but from a fasting perspective, pre-meal or during fasting is fine since it doesn’t break the fast. If taking 5 g at once causes stomach rumbling, try 2.5 g twice a day.

Precautions: Creatine is one of the most-researched supplements and is considered very safe for healthy individuals. The main issues to watch for are: (1) GI upset if taken in excessive dose – mitigate by proper dosing and water; (2) Weight gain – creatine can cause 1–2 kg of water retention in muscles initially, which is harmless but note this if you’re tracking weight; (3) Kidney concerns – creatine does increase creatinine levels (a lab marker), but studies show it does not harm kidneys in healthy people. Those with pre-existing kidney disease should consult a doctor before use. Ensure you drink sufficient water (at least 2–3 L/day) to aid kidney filtration. Also, avoid “creatine + huge caffeine + minimal water” combinations, as that could dehydrate you and strain the gut/kidneys. Finally, quality matters: use a reputable brand (Creapure or similar) to avoid impurities. In summary, creatine does not break a fast and can improve energy; just use responsibly with hydration for maximum benefitwhynotnatural.com.

Electrolytes (Salt, Potassium)

Benefits: Electrolytes – particularly sodium, potassium, and chloride – are crucial for hydration, nerve function, and brain signaling. When fasting, especially if you’re drinking lots of water or exercising, electrolyte levels can drop, leading to symptoms like fatigue, confusion, headache, or “brain fog”whynotnatural.com. Replenishing electrolytes during the fast can dramatically improve energy and mental clarity. For example, sodium and potassium regulate blood pressure and fluid balance; if they get too low, you may feel lightheaded or mentally foggy. Adequate electrolytes help maintain sharp cognitive function and stable mood by ensuring neurons fire properly. Many intermittent fasters find that adding a pinch of mineral salt to water or using electrolyte supplements banishes headaches and increases alertness during long fasts. Proper hydration with electrolytes also prevents muscle cramps and heart palpitations that sometimes distract from mental focus. In short, electrolytes act like an “electrical charge” that keeps your brain and body running optimally during fasting. They also won’t interfere with autophagy or ketosis – in fact, they support the body’s balance in the absence of foodwhynotnatural.com.

Fast-Safe?: Yes – pure electrolytes (like sodium chloride, potassium chloride, magnesium, calcium) have 0 calories and do not trigger insulin or mTORwhynotnatural.com. Consuming unsweetened electrolyte water or capsules will not break your fast. (Just avoid electrolyte drinks with sugar or significant flavor additives.) Maintaining electrolyte intake is often recommended as a safe practice during fastswhynotnatural.comwhynotnatural.com.

Gut Considerations: Electrolytes are usually fine on an empty stomach if taken correctly. A few pointers:

• Sodium (Salt): Generally well-tolerated. You can add ~1/4 to 1/2 teaspoon of Himalayan salt or sea salt to water and sip it. In someone with gastritis, very salty water might cause minor irritation or nausea – if so, take it slowly or divide into smaller doses throughout the day. You can also dissolve salt in warm water or broth (if doing a non-caloric bone broth fast) to make it gentler. Avoid chugging high-concentration salt water quickly, as that can cause vomiting (similar to a saltwater cleanse effect).

• Potassium: Be careful with potassium supplements – potassium pills (typically potassium chloride) can cause stomach upset for some and must be taken with plenty of water. In fact, prescription potassium tablets carry warnings to take with food because they can irritate the GI tract lining. For gastritis, it might be better to get potassium from a low-dose electrolyte blend rather than a single large potassium pill. Limit individual potassium doses (e.g. <300 mg at once) and swallow with a full glass of water. Another option is potassium salts (like Lite Salt, which is ~50% KCl) used sparingly in water.

• Bicarbonate: Some electrolyte mixes include bicarbonate (baking soda). Sodium bicarbonate can actually buffer stomach acid, which might temporarily soothe heartburn. However, too much bicarbonate on an empty stomach can cause bloating or upset. If you have acid-related pain, a small pinch of baking soda in water may help neutralize acid – but do not overdo it or you’ll feel gassy.

• Overall: Introduce electrolytes gradually and listen to your gut. They are generally considered essential and beneficial rather than harmful. In fact, meeting electrolyte needs can prevent some gastritis flare-ups that are triggered by dehydration or stress. Magnesium is discussed separately below, since it has additional brain benefits and considerations.

Typical Dosage: The goal is to meet roughly your daily electrolyte needs, adjusting for losses. A common regimen for fasting individuals:

• Sodium: ~1,500–2,300 mg per day (approx 3/4 to 1 tsp of salt, since 1 tsp salt = ~2,300 mg sodium). You can spread this out: e.g. a pinch (~300 mg) in each big glass of water, or use electrolyte tablets as directed. Athletes or heavy sweaters may need a bit more. Fasters often consume 2–3 grams of sodium daily to feel their best.

• Potassium: ~1,000–2,000 mg per day from supplements if diet (during eating window) is low. Do not take more than 500 mg at once. You might add 1/8 tsp of potassium chloride salt to water (that gives ~250 mg potassium) a few times a day. Never exceed 3,000 mg/day supplementally unless advised by a doctor, as too much potassium can affect heart rhythm.

• Chloride: Automatically provided with salt (salt is NaCl) or KCl, so no separate calculation needed.

• Others: Calcium needs (if not met by diet) are usually met during eating window or via a multivitamin; calcium on empty stomach isn’t necessary unless advised. Magnesium is addressed below.

Many fasting enthusiasts use ready-made electrolyte powders (ensure they are unsweetened) – for example, a packet might provide ~500–1000 mg sodium, 200–400 mg potassium, 60 mg magnesium, which you mix in water. Follow product dosing, but you can use 1–2 servings per fasting day. Always chase electrolyte supplements with water and don’t take a bunch right before lying down (to avoid reflux).

Precautions: Do not overconsume salt or potassium. While rare, it’s possible to overshoot: too much salt can raise blood pressure or cause swelling, and too much potassium can be dangerous to the heart. The amounts recommended above are moderate and generally safe. If you have hypertension or kidney issues, consult your doctor about appropriate electrolyte intake. Also, monitor how you feel: if taking electrolytes leads to nausea or bloating, you might be taking them too fast or in too high a dose for your stomach – cut back and increase gradually. People on medications (diuretics, blood pressure meds) should be cautious with potassium and sodium changes.

Finally, magnesium and calcium can have a laxative effect in large doses – but those are usually taken separately, so let’s move on to magnesium next.

Magnesium

Benefits: Magnesium is an essential mineral and electrolyte that plays a huge role in brain and nervous system function. It’s involved in hundreds of enzymatic reactions, including those that produce ATP energy, regulate neurotransmitters, and modulate stress hormones. If you’re low on magnesium, you might experience fatigue, poor concentration (“brain fog”), irritability, or sleep disturbanceswhynotnatural.com. Unfortunately, magnesium deficiency is relatively common – even in the general (non-fasting) population – and fasting can exacerbate it if you’re not careful. Supplementing magnesium during IF can help maintain mental clarity, stabilize mood, and support restful sleep. Many fasters report that magnesium in the evening helps them relax, sleep better, and wake up more refreshedwhynotnatural.com. Adequate magnesium can also reduce muscle cramps or tension that might distract you during the day. In short, magnesium is a brain fog fighter (by ensuring optimal nerve signaling) and a mood supporter (by aiding GABA and serotonin regulation). It’s also been shown to support cellular “house-cleaning” (autophagy) during fastingwhynotnatural.com, potentially enhancing fasting’s benefits.

Fast-Safe?: Yes – elemental magnesium has no calories and taking magnesium pills or powders will not break a fastwhynotnatural.com. It does not provoke an insulin response. You can take it on an empty stomach or with food; however, absorption and side effects can vary with form (see below). Magnesium is often recommended as a fasting supplement to keep levels upwhynotnatural.com.

Gut Considerations: Magnesium on an empty stomach is fine for most people, but the type of magnesium supplement matters:

• Forms like magnesium citrate, oxide, or sulfate are more likely to cause loose stools or stomach rumbling because they are not fully absorbed and draw water into the intestinesverywellhealth.comblog.metagenics.com.au. This laxative effect might be undesirable (unless you need help with constipation). Citrate can also sometimes cause minor stomach upset or acid reflux in sensitive folks.

• Gentler forms include magnesium glycinate (bisglycinate), magnesium malate, or magnesium gluconate. These tend to be better absorbed and easier on the stomach, causing less diarrheadroracle.ai. Magnesium glycinate in particular is known for its calming effect and low GI side effects – a good choice for gastritis sufferers.

• Slow-release or sustained-release magnesium capsules are another strategy. These release magnesium gradually, which can improve absorption and minimize GI upsetwhynotnatural.com.

• If you take magnesium, you might notice mild nausea if the dose is too high at once. To avoid this, take magnesium with a glass of water and consider splitting the dose (morning and evening) rather than all at once.

• Magnesium may help neutralize stomach acid slightly (magnesium hydroxide is an antacid), but typical supplements aren’t strong antacids. Overall, magnesium does not irritate the stomach lining; if anything, it can be soothing by supporting muscle relaxation (possibly easing that tight, crampy stomach feeling some gastritis patients get).

• Bottom line: For an empty stomach, magnesium glycinate ~ is best tolerated. Avoid magnesium forms that have caused you issues in the past. Start with a smaller dose (e.g. 100–150 mg elemental magnesium) to gauge tolerance.

Typical Dosage: Aim for 200–400 mg of elemental magnesium daily from supplements (which is around the recommended daily allowance for adults, 300–420 mg). The “elemental” magnesium is what counts – e.g. 1,000 mg of magnesium citrate might provide ~150 mg elemental magnesium (the rest is the citrate part). Check the label for “elemental magnesium” content. Many magnesium glycinate supplements provide ~100 mg per capsule. You could take one capsule in the morning and two in the evening, for instance, to total ~300 mg. Some individuals take their whole dose in the evening to aid sleep, since magnesium has a calming, anti-stress effect. This is fine during a fast (it’s still the fasting window if you stop eating at 8pm, for example). In fact, magnesium before bed can improve sleep quality which in turn improves next-day alertness. If brain fog is your main issue during the day, you could take some magnesium in the morning as well.

Because magnesium is so crucial, you should be consistent daily. If you eat magnesium-rich foods (nuts, greens, etc.) in your eating window, you might supplement less. If your multivitamin (taken in feeding window) has magnesium, factor that in (though multis often don’t have much magnesium due to pill size limits).

Precautions: The main side effect to monitor is diarrhea or loose stools, indicating you took more magnesium than your gut could absorb. If this happens, reduce the dose or switch forms. Very high doses of magnesium (well above 500 mg at once) can cause cramping, nausea, or even an unsafe drop in blood pressure in extreme cases, but such doses are uncommon from supplements alone. People with kidney disease should not take magnesium without medical supervision, as they may have trouble excreting excess – this could lead to dangerously high magnesium levels (marked by weakness or slow heart rate). That said, healthy kidneys easily handle recommended doses by excreting surplus. Magnesium can interact with certain antibiotics and thyroid medication (it can bind them in the gut), so take magnesium at a different time from those meds. If you’re on a medication regimen, check with your provider, but generally spacing magnesium and meds by a couple hours avoids interactions. Finally, note that magnesium can cause drowsiness in some, so be cautious if driving or operating machinery until you know how it affects you (especially with forms like magnesium glycinate). Overall, magnesium is a safe, essential supplement that can significantly improve fasting tolerance by preventing “brain fog” and muscle acheswhynotnatural.com – just adjust the form and timing to suit your stomach.

L-Tyrosine

Benefits: L-tyrosine is an amino acid that serves as a precursor to key neurotransmitters, including dopamine, norepinephrine, and epinephrine (all of which influence focus, drive, and mood). Supplementing tyrosine can sharpen mental performance under stress or fatigue. Notably, studies have found that taking tyrosine can improve working memory, cognitive flexibility, and alertness during acute stressorshealthline.com. For example, in military and clinical research, tyrosine helped people stay mentally sharp when they were sleep-deprived or multitasking under pressurehealthline.com. Intermittent fasting can be a mild stressor (especially early in the fast or if you’re adjusting to the routine), and some people report “foggy” thinking when blood sugar dips. Tyrosine may counteract that by ensuring your brain has the raw materials to make catecholamines (the focus and energy neurotransmitters). It might also uplift mood and motivation in scenarios of dopamine depletion – some evidence suggests tyrosine can fight off feelings of low energy or low motivation, particularly in individuals who are under strainhealthline.comhealthline.com. While tyrosine is not a stimulant, it’s more of a “mental resilience” booster: it helps you maintain clarity when you’d otherwise be drained. This makes it popular among biohackers and those practicing IF looking to enhance verbal fluency and mental agility during long morning fasts.

Fast-Safe?: Yes – L-tyrosine is calorie-free at typical doses. A standard dose (500–1,000 mg) has at most 2–4 calories, which is negligible and does not provoke an insulin response. Tyrosine in pure form doesn’t come with carbs or fillers that could break a fast (just avoid tyrosine drinks that might have sweeteners). Research indicates tyrosine can be taken in fasting conditions (even in military studies, they administer it to fasting soldiers to test cognition). It’s water-soluble and fine on empty stomach.

Gut Considerations: L-tyrosine is usually well-tolerated on an empty stomach, but a few individuals might notice mild nausea if taking higher doses (e.g. 2 g) at once. If you have a sensitive stomach, start with 500 mg or capsule, and you can take it with a large glass of water to dilute it in the stomach. Tyrosine is an amino acid, but unlike some (e.g. tryptophan), it tends not to cause GI upset in normal doses. No significant gastritis concerns have been documented – it’s not acidic or irritating. One thing to watch: some tyrosine supplements come in the N-acetyl-L-tyrosine form (NALT); NALT is more water-soluble but actually less bioavailable (your body converts only part of it to tyrosine)healthline.com. It’s still fine, but you might need a higher dose of NALT to equal plain tyrosine. From a stomach standpoint, either form is fine. If you do feel any queasiness, you could try taking tyrosine with a small amount of water with salt or baking soda (to neutralize any slight acidity from the HCl salt form), but this is rarely needed. Overall, tyrosine is gentle – just avoid taking with other protein (if you were eating) because it competes with other amino acids for absorption; but during fasting that’s not an issue.

Typical Dosage: 500–1,000 mg about 30–60 minutes before a mentally demanding task or whenever you tend to feel sluggish (morning or early afternoon) is a common regimenexamine.comhealthline.com. For example, one might take 500 mg upon waking and another 500 mg around noon if needed. In studies, single doses up to 2,000 mg have been used to sustain cognition in stress (and in military contexts, sometimes even higher, ~100–150 mg per kg which is ~7–10 g/day in divided dosesperformancelab.com, but this is not typical for daily use). For everyday brain fog relief, stick to 500–1,000 mg. Tyrosine kicks in fairly quickly, within 30 minutes, and effects can last a few hours (it’s used up as neurotransmitters are made). It’s often taken acutely (as needed) rather than as a daily must-take, because if you’re not in a stressful situation you may not notice a differencehealthline.com. If you find you do have better focus and mood on tyrosine consistently, you can use it daily or just on fasting days that coincide with heavy workloads.

Precautions: Tyrosine is considered safe for most people (the FDA has it GRAS, and studies up to 3 months at high dose showed no serious issueshealthline.com). That said, there are a few important precautions:

• Thyroid Disorders: Tyrosine is a precursor to thyroid hormones (thyroxine), so taking it might theoretically raise thyroid hormone levelshealthline.com. If you have hyperthyroidism or are on thyroid medication, be cautious and consult your doctor – extra tyrosine could overdo it. Those with hypothyroidism on medication usually won’t have an issue at moderate doses, but still inform your doctor.

• MAOI Antidepressants: If you take monoamine oxidase inhibitors, you must manage dietary tyrosine/tyramine to avoid hypertensive episodes. While tyrosine itself isn’t tyramine, it can convert to it. Supplemental tyrosine could potentially interact with MAOIs, risking elevated blood pressurehealthline.comhealthline.com. It’s best not to take tyrosine if you are on MAOIs or certain other psychiatric meds without medical advice.

• Levodopa (Parkinson’s med): Tyrosine competes with L-Dopa for absorptionhealthline.com, so spacing them out by a couple hours is necessary if you take both.

• Migraines or Melanoma: People with a history of migraine headaches sometimes find supplements that affect catecholamines (like tyrosine) can be a trigger – though this isn’t common, just be aware if you get headaches. Also, tyrosine is not recommended for individuals with melanoma (a type of skin cancer) because melanoma cells feed on tyrosine.

• Overuse: Taking tyrosine when you’re not stressed or fatigued likely doesn’t boost performance furtherhealthline.com. So more is not better in a normal state. Stick to using it to mitigate brain fog rather than megadosing daily for no reason.

• Side Effects: Rarely, side effects can include restlessness, anxiety, or palpitations, since it can increase adrenaline. If you feel jittery or have trouble sleeping, reduce the dose or timing (don’t take tyrosine late in the day). Mild nausea or upset has been reported in a small number of people – if this occurs, taking a smaller dose or with some water usually fixes it.

In summary, L-tyrosine is a useful nootropic for fasting, helping maintain focus and mental energy under stresshealthline.com. Use it responsibly and it can make your fasting window mentally sharper and more productive.

Lion’s Mane Mushroom (Hericium erinaceus)

Benefits: Lion’s Mane is a medicinal mushroom famed for its nootropic and neuroprotective properties. It may improve memory, learning, and mood over time by promoting nerve growth factor (NGF) and brain plasticity. A small clinical study in adults aged 50–80 showed that taking Lion’s Mane extract (4 capsules totaling 1 g per day) for 16 weeks significantly improved cognitive function scores compared to placebobusinessinsider.com. Participants’ mental function declined back to baseline a few weeks after stopping the supplement, suggesting Lion’s Mane was indeed helping their cognitionbusinessinsider.com. For those who experience brain fog, Lion’s Mane can gradually enhance clarity and recall – it’s not a stimulant, but rather a brain health booster that may take a few weeks of consistent use to noticeably improve mental sharpness. In addition to cognitive benefits, Lion’s Mane has shown promising effects on mood and anxiety. In one 8-week study, people who took Lion’s Mane had about a 30–50% reduction in depression and anxiety symptoms relative to baselinebusinessinsider.com. Users often report a subtle mood lift and better focus after a couple of weeks on Lion’s Mane.

For those with gastritis, Lion’s Mane has a bonus: it’s traditionally used in East Asia to support digestive health. It appears to have anti-inflammatory and healing effects on the gut lining. Notably, a small 1985 trial in patients with chronic atrophic gastritis found Lion’s Mane extract (taken before meals for 3 months) led to significant improvements in abdominal pain and gastric inflammation vs. placebobusinessinsider.com. So Lion’s Mane may actually soothe the stomach and assist in gastritis recovery – a rarity among supplements in this list!

Fast-Safe?: Yes – pure Lion’s Mane extract or powder has minimal calories. A typical capsule dose (500 mg to 1 g) contains maybe 2–4 calories’ worth of mushroom polysaccharides, which is nutritionally negligible and won’t spike insulin. It’s considered fasting-friendly because it doesn’t have protein or sugars in significant amounts. (If you mix it into tea or coffee as a powder, just ensure any base you use is calorie-free.) Lion’s Mane does not interfere with ketosis; it might even complement fasting by reducing inflammation.

Gut Considerations: Lion’s Mane is generally very gentle and even potentially beneficial for the GI tract. Unlike some herbs, it’s not known to cause stomach upset for most people. In fact, as mentioned, it has been used to treat gastritis and ulcers historicallyverywellhealth.combusinessinsider.com. The mushroom’s polysaccharides may act as prebiotics and help the gut lining. That said, any fiber or mushroom material can, in rare cases, cause mild gas or bloating if one’s digestive system isn’t used to it. A few anecdotal reports (e.g. on forums) mention stomach discomfort from Lion’s Mane, possibly due to its fiber content or an allergylongevitybotanicals.com. To mitigate any chance of upset: start with a lower dose (e.g. 500 mg) and see how you do. Taking it with a glass of water is fine; you don’t need food alongside, since it’s not an irritant like NSAIDs. If you use a raw powder (instead of an extract), the higher fiber might cause more GI rumbling – in that case, consider switching to a concentrated extract (often labeled 8:1 or similar), which contains less indigestible material. Allergies: If you’re allergic to mushrooms, avoid Lion’s Mane (it can cause skin rashes or asthma-like reactions in those with fungal allergiesbusinessinsider.com). But if you tolerate culinary mushrooms, Lion’s Mane is unlikely to cause any issues. It does not produce stomach acid or have caffeine, so it’s considered safe for gastritis – indeed, possibly protective.

Typical Dosage: 500 mg to 1,000 mg (0.5–1 g) per day is a common dosage range for cognitive benefits. In the cognitive study, about 1,000 mg per day (in 3–4 divided doses) was usedbusinessinsider.com. Many supplements provide 500 mg per capsule; taking one in the morning and one in the evening (total 1 g) is convenient. Some people take up to 2 g per day of Lion’s Mane for stronger effects (often split morning and afternoon). Even doses up to 3 g have been used in human studies with good safety. For brain support, consistency is key – try to take it daily for at least 4–12 weeks to gauge full effects. You can take Lion’s Mane during the fasting window without breaking the fast. Time of day isn’t critical, but some find it slightly energizing or clarity-promoting, so morning or midday is ideal. Others take it at night for neuroprotection; it doesn’t usually interfere with sleep. Find what works for you. If you’re aiming for gut healing, taking it before meals (as in the gastritis study) might be beneficial, but that’s during eating window; however, even during fasting it could exert positive effects on the gastric mucosa.

Precautions: Lion’s Mane is very safe for most people. Documented side effects are minimal – a large safety study noted only mild issues like stomach discomfort in a few individualslongevitybotanicals.combusinessinsider.com. As mentioned, those with a mushroom allergy should avoid itbusinessinsider.com. There’s no evidence of toxicity; it’s been taken at 1 g daily for months in trials without problemsbusinessinsider.com. One theoretical precaution: Lion’s Mane might lower blood glucose slightly (as some mushrooms do) – if you are diabetic on medication, monitor your blood sugar to ensure it doesn’t go too low. It can also have mild blood-thinning effects, so if you’re on anticoagulant drugs or about to have surgery, check with your doctor. Pregnant or breastfeeding women are generally advised to avoid it just due to insufficient research (this is standard for most supplements)businessinsider.com. Finally, because Lion’s Mane can stimulate nerve growth factor, some with autoimmune conditions or asthma have wondered if it could flare symptoms; current evidence doesn’t show any harm, but listen to your body. Overall, it’s a gut-friendly and brain-friendly supplement that fits well into a fasting regimen for boosting memory and mood.

Rhodiola Rosea

Benefits: Rhodiola is an adaptogenic herb that helps the body resist physical and mental stress. For someone fasting, Rhodiola can provide a gentle lift in energy, mental clarity, and mood stability, especially during times when you might feel drained. Studies show that Rhodiola can reduce fatigue and improve mental performance in stressful conditionslivemomentous.com. It has been used to fight “brain fog” and burnout – one study on night-shift doctors found Rhodiola improved their cognitive function during overnight dutylivemomentous.com. It appears to work by modulating stress hormones (like cortisol) and supporting neurotransmitters like serotonin and dopamine. Users often report better focus, faster thinking, and less mental fatigue on Rhodiola, making it popular as a daytime nootropic. Additionally, Rhodiola has significant benefits for mood: it can help alleviate mild anxiety and depression symptoms and promote a more balanced, resilient emotional statelivemomentous.com. In fact, some researchers consider it a potential herbal antidepressantlivemomentous.com. This mood support can be valuable for fasters, as fasting itself can be a hormetic stressor that occasionally triggers irritability in some people. By using Rhodiola, you may feel calmer yet more energized, with improved motivation and even verbal fluency (since your fatigue and anxiety are reduced).

Fast-Safe?: Yes – Rhodiola capsules or drops are calorie-free. It’s typically an extract of the root (standardized to active compounds like rosavins and salidroside) with no significant macronutrients. It won’t break ketosis or raise insulin. In fact, some people use Rhodiola while fasting for its synergistic fatigue-fighting effects, as it’s also known to potentially enhance exercise performance and fat metabolism. So it is fully compatible with fasting metabolism.

Gut Considerations: Rhodiola is generally well-tolerated on an empty stomach, but it can depend on the person. It’s often recommended to take Rhodiola before breakfast (i.e. on an empty stomach) because taking it late in the day can be too stimulating. Many people do fine taking it first thing in the morning with water. However, for some individuals, herbal extracts can cause slight stomach upset or nausea if taken without any food. Reports of Rhodiola causing digestive issues are rare; occasionally mild nausea, dizziness, or dry mouth has been notedpsychcentral.comhealth.com. If you have gastritis, it’s unlikely Rhodiola will irritate the stomach lining – in fact, animal studies suggest it might protect the stomach from ulcers by reducing inflammationsciencedirect.com. Traditionally in some systems, Rhodiola has even been used for GI ailments, as certain components have anti-inflammatory effects on the gastric mucosaherbalreality.com. That said, each person is different. To play it safe, you could start with a low dose (100 mg) and see if you feel any stomach discomfort. You could also take it with a small amount of water or herbal tea (nothing caloric) to dilute it. Avoid taking Rhodiola with coffee on an empty stomach if you’re sensitive – the combo might be a bit overstimulating and could churn your stomach. Most people with gastritis tolerate Rhodiola fine, but if you notice any burning or queasiness, consider taking it closer to your eating window (with a small snack) instead of during the strict fast.

Typical Dosage: 200–400 mg per day of a Rhodiola rosea extract standardized to ~3% rosavins is a typical dose for cognitive and mood benefitswebmd.com. Many supplements suggest 200 mg twice a day (morning and early afternoon). For example, 200 mg before breakfast and 200 mg around lunch (or early fasting afternoon) can keep your energy up. It’s best not to take Rhodiola in the late afternoon or evening, as it can interfere with sleep in some people (it’s not a traditional stimulant, but it can be activating). The effective dose range in studies is often ~300–600 mg per day; doses above 600 mg usually haven’t shown added benefitwebmd.comexamine.com. In some research for acute stress, even a single dose of ~370 mg showed mental performance improvements within hourslivemomentous.com. So you can use it acutely (like on a day you anticipate high stress or extra fatigue) or daily as a tonic. If you are new to Rhodiola, try 100–150 mg first; some products even come in 100 mg capsules which you can use to titrate up. Since Rhodiola has a somewhat U-shaped response curve (very high doses might be less effective than moderate ones), more is not necessarily better. Find the sweet spot – many like 300 mg/day. Note: Taking Rhodiola cyclically (for example, 5 days on, 2 days off) is suggested by some herbalists to maintain its efficacy long-term, though evidence is anecdotal. Also, pair it with healthy habits (sleep, hydration) for best results; it’s a helper, not a crutch.

Precautions: Rhodiola is safe for most but a few notes:

• It can cause jitteriness, irritability, or insomnia if the dose is too high or taken too late (because it can boost norepinephrine a bit). If you feel overly wired or anxious on Rhodiola, reduce the dose or discontinue.

• Individuals with bipolar disorder or who are prone to manic episodes should be cautious – any antidepressant-like supplement might theoretically trigger mania or rapid mood shifts. There’s a case report or two of Rhodiola contributing to insomnia or agitation in such patients. So if you have a serious mood disorder, get medical advice.

• Rhodiola might lower blood pressure slightly in some (due to stress reduction). If you’re on BP meds, monitor in case it adds to the effect. Conversely, if you have low blood pressure naturally, be aware Rhodiola could make you a bit lightheaded (though it’s usually stabilizing, not strongly pressure-lowering).

• It may interact with diabetes medication by improving blood sugar control (monitor blood sugar so it doesn’t go too low). And because it influences neurotransmitters, use caution if combining with other stimulants or antidepressants – there isn’t a well-known harmful interaction, but stacking multiple mood modulators can be unpredictable.

• As with most herbs, data in pregnancy/lactation is lacking, so those individuals should likely avoid Rhodiola.

• Quality matters: use a Rhodiola supplement from a reputable source; Rhodiola is sometimes adulterated with other species. A proper product will list Rhodiola rosea and standardization (e.g. “3% rosavins, 1% salidroside”).

• If you experience dry mouth, dizziness, or excess saliva, those are minor side effects reported by somehealth.com – usually resolving by adjusting dose or timing.

Overall, Rhodiola can be a fantastic aid for brain fog and mood dips during fasting, helping you feel more resilient and focusedlivemomentous.comlivemomentous.com. Treat it with respect (don’t mix with too many stimulants initially) and it can safely enhance your fasting experience.

Vitamin B12 (and B-Complex Vitamins)

Benefits: B vitamins, and vitamin B12 in particular, are critical for brain function, energy production, and mood regulation. If you are deficient in B12 or other B vitamins, you’ll almost certainly feel tired, foggy, and potentially low in mood. Fasters need to ensure they still get their micronutrients, since no food is consumed for extended periods. Fortunately, taking B vitamins during a fast is possible and can help prevent deficits. Vitamin B12 supports healthy nerves, helps form red blood cells, and is involved in synthesizing neurotransmitters. Low B12 (common in vegetarians, older adults, or those with gastritis, because gastritis can reduce B12 absorption) can cause fatigue, memory problems, poor concentration, and even depression. Supplementing B12 can thus restore normal cognitive function and energy in deficient individuals. Even if you’re not deficient, a B12 boost during fasting might help maintain optimal energy levels. Other B vitamins (like B6, B9 folate, B1, B5, etc.) are co-factors in metabolism and brain chemistry: they help convert food (or stored nutrients during fasting) into energy, support the synthesis of neurotransmitters (like serotonin, GABA, dopamine), and aid in myelin formation for nerveswhynotnatural.com. Ensuring you have sufficient B-complex vitamins can reduce brain fog and irritability that come with any dietary stress. Some fasters feel a clear-headed “high” when in ketosis, but others may feel a bit off – B vitamins might make the difference in how you feel. In short, B12 and B-complex act as metabolic spark plugs, keeping your brain’s engine running smoothly during fasting. They won’t stimulate you like caffeine, but they help unlock energy from within and prevent the blahs that come from low B-vitamin status.

Fast-Safe?: Yes – pure B vitamins have no calories and do not break a fastwhynotnatural.com. They are water-soluble vitamins, so they don’t require fat or significant digestion. Taking a B-complex or individual B12 pill during fasting is fine and won’t interrupt ketosis or autophagywhynotnatural.com. Do avoid gummy or chewable vitamins that contain sugars – opt for capsules, tablets, or sublinguals without caloric additives. Multivitamin pills typically contain B vitamins and are usually okay if they have no caloric fillers (check that they don’t include things like fat-containing beads or sweet coatings – most don’t). In summary: B12/B-complex are fasting-compatible, which is why many intermittent fasting guides list them as allowed supplementswhynotnatural.com.

Gut Considerations: Here we must be careful: B vitamins can cause stomach discomfort or nausea in some people when taken on an empty stomach. It varies by person and by vitamin:

• B12: Usually very well-tolerated. Many B12 supplements are sublingual (dissolve under tongue) or drops, which bypass the stomach anyway. If swallowed as a pill, B12 is not known to cause GI upset on its own. B12 is actually recommended for people with gastritis (since gastritis often leads to B12 malabsorption). High-dose oral B12 (500–1,000 mcg) is fine on empty stomach, though a handful of people report slight nausea – often due to the tablet additives or because B12 can activate metabolism a bit.

• B6 (pyridoxine): In a B-complex, B6 in high doses can sometimes cause light nausea or tingling. But standard doses (~10–50 mg) usually are okay. B6 on empty stomach can cause a warm sensation or slight flush in some.

• Niacin (B3): Immediate-release niacin can cause a “flush” – tingling and redness – which some might interpret as discomfort. Many B-complex formulas use niacinamide (no flush form) or low-dose niacin to avoid that. If your B complex causes flushing, know it’s likely niacin and not a harmful effect, but it can be unpleasant if unexpected.

• Folate (B9): Generally fine, though very high doses might cause bloating or bitter taste. Folic acid is okay on empty stomach, but some with sensitive stomachs might prefer methylfolate forms. Not usually a culprit of GI issues.

• Thiamine (B1): High-dose thiamine can cause nausea in some individuals. But in most B-complexes, the dose is moderate (~50–100 mg) and typically okay.

• Riboflavin (B2): Harmless but turns urine bright yellow (normal). No stomach issues typically.

• General B-Complex: Many people feel a bit queasy if they take a potent B-complex first thing in the morning without any food. To mitigate this: try taking it with plenty of water, or during your feeding window if you consistently have trouble. Another hack: you could take B vitamins with a few bites of low-calorie food like cucumber slices (practically negligible calories) if absolutely needed to settle stomach, but this is usually not necessary for most.

For gastritis specifically: If your gastritis is severe, you might consider taking B-complex in the middle of your eating window instead, because any supplement pill could be a bit irritating to raw stomach lining. However, if it’s mild or under control, a morning B12 or B-complex shouldn’t cause flare-ups. In fact, correcting B12 deficiency can help gastritis in the long run (pernicious anemia gastritis requires B12 injections or high dose oral B12). Listen to your body – if a B pill triggers pain, just schedule it with a meal. Sublingual B12 is a great workaround for gastritis folks since it bypasses the stomach (and bypasses the need for intrinsic factor). Also note: B vitamins have a somewhat noticeable taste and smell (especially B1, B6); if you burp them up, it’s unpleasant. Drinking a full glass of water and staying upright for 10–15 minutes after taking them helps ensure they move down and don’t reflux.

Typical Dosage: This depends on whether you supplement individual B’s or a B-complex:

• Vitamin B12: For general health, 250–500 mcg daily of cyanocobalamin or methylcobalamin is common (many supplements provide even 1,000 mcg, which is fine as B12 has no upper toxicity at reasonable levels). If you have low B12 or absorption issues, doses of 1,000–2,000 mcg/day or weekly high doses are used to normalize levels. You can take B12 as a pill or liquid in the morning during your fast. Sublingual B12 (usually 500–1,000 mcg) can be placed under the tongue; it typically has some flavoring but if sugar-free it won’t break fast. Alternatively, injections (if medically indicated) obviously bypass fasting concerns entirely.

• B-Complex: Many “B-50” or “B-100” complexes are available. A B-50 means ~50 mg of most B vitamins (which is several thousand percent of RDA, but they’re water-soluble; you’ll pee out excess). B-100 is double that. For daily use, a B-50 complex daily is often sufficient. You might also take it only a few times a week if your diet in eating window covers some Bs. Dose timing: morning with water is fine if tolerated; otherwise, take in the eating window.

• Individual B’s: If you target specific ones – e.g. B6 for mood (usually 25–50 mg), or biotin for other reasons (5,000 mcg for hair, etc.) – follow those specific dosages. Most can be taken during fasting with no issues (biotin has no known GI problems).

• Vitamin C (bonus): Though not a B, it’s often included in discussion. Vitamin C is also water-soluble and fast-safewhynotnatural.com, but pure ascorbic acid can be acidic on an empty stomach. If you want vitamin C during fasting, consider a buffered form (like sodium ascorbate) to reduce stomach irritation. However, if you eat veggies and fruits in your eating window, you might not need extra C on fast days except for general immunity.

Precautions: B vitamins are generally very safe because excess is excreted, but here are a few:

• Don’t overdo niacin without medical guidance. High niacin (like 500 mg) can cause significant flushing and liver enzyme elevations if sustained. In a B-complex it’s usually low (like 50 mg or less).

• Vitamin B6: Chronic mega-doses (hundreds of mg daily for months) can cause reversible neuropathy (nerve tingling). Stay at 100 mg/day or less of B6 unless directed by a doctor.

• Interactions: B vitamins don’t usually interfere with meds, though folic acid can mask B12 deficiency symptoms, so ensure you have B12 alongside folate. Also, high dose biotin can interfere with certain lab tests (thyroid, troponin), so pause biotin a few days before blood tests.

• Urine color: Expect neon yellow urine when you take B vitamins – this is normal (excess riboflavin excretion).

• Energy feeling: Some people feel a surge of energy after a B-complex (especially if they were low in B12 or B1). This can feel a bit like a mild jitter for a short time. It’s not a stimulant per se, just your metabolism thanking you. If it bothers you, take it earlier in the day.

• Quality: If you have the MTHFR gene variant or concerns about folic acid, use a B-complex with methylfolate and methylcobalamin (active forms of B9, B12). This is more of a personalized nutrition point.

• Essential: Remember, B vitamins are “essential” – your body needs them, and fasting doesn’t provide them. If your diet on feeding times covers them, great, but if not, supplementation is wise to avoid deficiencies (which absolutely cause brain fog). The good thing is they support fasting rather than hinder itwhynotnatural.com.

In summary, B12 and B-Complex vitamins can be taken in the fasting window to support energy and cognitionwhynotnatural.com, with minimal risk. Just be mindful of possible mild nausea – if you experience that, shift them to meal-time. Many find that maintaining B vitamin intake keeps them feeling “nutritionally fed” and mentally sharp even while calories are absent.

Citicoline (CDP-Choline)

Benefits: Citicoline is a choline donor nootropic that has gained popularity for boosting brain function. It’s essentially a precursor for brain phospholipids and acetylcholine (a neurotransmitter crucial for memory and learning). Citicoline (also known as CDP-Choline) can improve memory, focus, and mental energy, particularly if one’s choline intake is low or cognitive demand is highhealthline.com. Research suggests it enhances attention and memory performance in healthy individuals and those with age-related cognitive declinehealthline.com. For example, a 2022 review of 14 studies concluded that citicoline supplementation led to better memory recall and attentional focus in people without dementiahealthline.com. It’s thought to work by increasing levels of acetylcholine and supporting mitochondrial function in neurons – effectively acting as a brain “fuel” and repair helper. People practicing IF might choose citicoline to combat the slight forgetfulness or word-finding issues (verbal fluency dips) they notice when fasting. It’s considered a “clean” nootropic because it’s actually a compound naturally found in the body (and in brain metabolism). Another benefit: citicoline can enhance the release of dopamine in the brain, which might translate to improved mood and motivation during those fasting hours when you need to stay productive. It also supports neuronal membrane integrity (since choline is used in making phosphatidylcholine), potentially offering neuroprotective effects in the long runhealthline.comhealthline.com. In short, citicoline can make your brain run more efficiently on the fuel it has, which is particularly useful when no new glucose is coming in (like during a fast).

Fast-Safe?: Yes – citicoline is calorie-free and will not break a fast. It’s a pure molecule (often sold as cognizin® or similar) and has no carbs, fat, or protein. It typically comes in capsules or tablets. Some nootropic drink mixes include citicoline but watch out that those don’t have other caloric ingredients. Citicoline itself might have a tiny energy content per gram (negligible even if so – likely <5 calories for a 500 mg dose). It does not raise blood sugar or insulin. In fact, as a neuro-supportive nutrient, it can complement fasting by helping the brain utilize ketones and glucose more effectively (though that’s an indirect effect). So it’s fully fast-compatible.

Gut Considerations: Citicoline is usually well tolerated. It dissolves in water and is absorbed in the small intestine. Clinical trials note that side effects are rare and generally mildhealthline.com. The most common might be a brief headache or slight nausea in a small subset of usershealthline.com. From a gastritis perspective, citicoline is not known to irritate the stomach lining; it’s not acidic or erosive. If anything, any choline supplement can sometimes cause a fishy body odor in high amounts due to gut bacteria metabolizing choline into TMAO, but this is more of a metabolic note and not an acute GI side effect. At typical doses, this shouldn’t be significant. People with very sensitive stomachs might experience a touch of nausea if taking it completely dry – to avoid that, take the capsule with a full glass of water. Unlike some supplements, citicoline doesn’t require food for absorption, nor does it cause reflux. One thing to note: because citicoline can moderately stimulate dopamine receptors, a few people report feeling a bit jittery or restless initially – but this is a central effect, not a stomach effect. If you feel that, maybe split the dose (half in morning, half later) to ease into it. Overall, gut-friendly and fine for gastritis folks.

Typical Dosage: 250–500 mg per day is a common dosage range for cognitive enhancementalzdiscovery.orgscirp.org. Many products provide 250 mg per capsule; some provide 500 mg. For general brain health or mild focus needs, 250 mg is a good starting point. For more noticeable memory support or in older individuals, 500 mg daily is often used. Doses up to 1,000 mg/day have been used in studies on memory with good effect (sometimes split 500 mg twice a day)pmc.ncbi.nlm.nih.gov. But beyond 500 mg, you get into diminishing returns for most healthy people – and higher doses might be overkill unless treating a neurological condition. Because citicoline is stimulating for some, morning or early afternoon dosing is recommended (taking it late in the day could, in theory, interfere with sleep by boosting brain activity, though it’s not a stimulant like caffeine). It is fine to take during your fasting window; in fact, some take it on an empty stomach in the morning to get the brain-boosting effect for the workday. Citicoline tends to show benefits after days to weeks of continuous use, but some people feel a subtle focus lift within a few hours of a dose (especially if they were choline-deficient from diet). Note: If you already take a choline-rich diet or lecithin, you might not notice as big an effect, but it can still support memory.

Precautions: Citicoline is considered very safe, with low toxicity and low risk of side effectshealthline.com. A few precautions:

• Headache or Insomnia: A small number of users get a mild headache from citicoline. This might be due to increased cholinergic or dopaminergic activity. If this happens, lowering the dose or taking it earlier in the day can help. Ensure you’re also staying hydrated.

• Blood Pressure: Citicoline can cause a slight blood pressure increase in some individuals (likely due to neurotransmitter effects). If you have uncontrolled high blood pressure, monitor when you start citicoline. Conversely, some studies noted it can lower blood pressure a bit – effects seem inconsistent but generally minor.

• Interactions: There are no major drug interactions known for citicoline. It’s sometimes used alongside cognitive enhancers or even medications post-stroke. It should be fine with most supplements too. If you’re taking a separate carnitine or choline supplement, you might not need both as they overlap in some pathways.

• Pregnancy/Nursing: Insufficient data, so better to avoid during those times unless prescribed.

• Overstimulation: In rare cases, someone might feel overly restless or get mild diarrhea (choline can stimulate peristalsis) at high doses. If so, cut back.

• Cost: Not a safety issue, but worth noting – citicoline is more expensive per dose than many basic supplements. So some opt for Alpha-GPC (another choline donor) as an alternative. Alpha-GPC 300 mg ? Citicoline 500 mg in terms of choline provided. Alpha-GPC is also fast-safe but can cause heartburn in some. Citicoline tends to be better tolerated overall.

To conclude, citicoline is a potent nootropic for memory and focus that aligns well with intermittent fasting. It ensures your brain has the choline it needs to perform, even when your diet is on pausehealthline.com. By including it, you can support your cognitive function and perhaps notice crisper thinking and better recall, all while staying in a fasted state.

---

The above supplements can be powerful tools to optimize your fasting period productivity and well-being. Below is a comparison table summarizing each supplement’s key points for quick reference: