Every ingredient we track across 130 entries — what it does, the dose the research actually uses, how strong that research is, and the catch worth knowing before you buy.
Serotonin precursor that reliably reduces appetite and carbohydrate cravings.
Watch out: Do not combine with antidepressants. Can cause nausea and drowsiness.
Brain-permeable carnitine used for mental energy.
Watch out: Best evidence is in older adults, not trained lifters.
The botanical name for grains of paradise — activates brown fat to raise calorie burn slightly.
Watch out: Small effect; only standardised 6-paradol extracts were studied.
Arginine metabolite popular for a long-lasting pump feel.
Watch out: Human pump data is essentially anecdotal.
Included in some formulas; no established clinical effect on its own.
Raises acetylcholine for sharper mind–muscle connection and focus; some power-output data.
Watch out: Commonly dosed at 150–300 mg, which is under the studied range.
Branded ginger relative marketed for 5 hours of alertness without stimulation.
Watch out: Two small manufacturer-run trials; no independent replication.
Used to amplify stimulant feel and mood.
Watch out: No meaningful human trials; interacts with drug metabolism.
Small effects on post-meal blood sugar and appetite.
Watch out: Powdered forms rarely disclose acetic acid content.
Direct nitric oxide precursor, but largely destroyed in the gut before it can work.
Watch out: Citrulline raises blood arginine better than arginine does. GI upset at high doses.
Lowers cortisol and anxiety, with modest strength and recovery gains over 8+ weeks.
Watch out: Unbranded, unstandardised extracts vary a lot. Needs daily use — a single serving does nothing.
Reduces cortisol and anxiety, with modest strength and recovery benefits over 8+ weeks.
Watch out: A daily ingredient — a single pre-workout serving does nothing acutely.
Astragalus/ginseng blend claimed to increase absorption of amino acids and other actives.
Watch out: Brand-funded, mostly cell and animal data.
Genuinely improves blood-sugar control and insulin sensitivity — close to a pharmaceutical effect.
Watch out: GI upset is common and it interacts with several medications. Rarely dosed properly in a blend.
Buffers muscle acid, adding real endurance in the 60-second to 4-minute effort range.
Watch out: Needs weeks of daily use — the tingling is not the benefit.
Included in some formulas; no established clinical effect on its own.
Modest gains in power output and body composition across several trials.
Watch out: Also a cumulative daily ingredient, not an acute one.
Absorption enhancer — meaningfully raises uptake of poorly absorbed compounds like curcumin.
Watch out: Does nothing on its own and can affect how some medications are metabolised.
Trace mineral with small effects on free testosterone and vitamin D status.
Watch out: Effects are modest and mostly in deficient people.
The one stimulant with airtight evidence: more alertness, less perceived effort, better endurance and output.
Watch out: Tolerance builds fast. Above ~400 mg most people just get jittery, not stronger. Avoid within 8 h of bed.
Essential mineral for muscle contraction; usually present as a carrier salt.
Watch out: Rarely a meaningful dose in a pre-workout.
Small bump in energy expenditure plus real appetite suppression.
Watch out: Uncoated chilli extract causes burning and reflux — the coating matters.
Acetyl-L-carnitine — the brain-permeable form, used for mental energy rather than fat loss.
Watch out: Best evidence is in older adults; little in trained lifters.
Glycine propionyl-L-carnitine, used for nitric oxide and blood flow more than for fat burning.
Watch out: A handful of small trials; expensive per gram.
L-carnitine L-tartrate reduces muscle damage and speeds recovery between sessions.
Watch out: A recovery ingredient, not a fat burner, at this dose.
Citicoline — choline source with attention and working-memory support.
Watch out: Effects are subtle and build over weeks rather than in one session.
Electrolyte that pairs with sodium and potassium to hold fluid balance during heavy sweating.
Watch out: Comes along with salt; never a reason to pick a formula.
Cheapest choline source; mostly a label filler at typical doses.
Watch out: Poor brain uptake compared with Alpha-GPC or citicoline.
Trace mineral marketed for cravings and blood sugar.
Watch out: Meaningful effects only in people who are deficient.
Raises nitric oxide for stronger pumps, better blood flow and extra reps late in a set.
Watch out: Below 6 g the effect largely disappears — the most commonly underdosed pump ingredient.
Citrulline bonded with malic acid; same pump benefit plus modest endurance support.
Watch out: 8 g of 2:1 only yields ~5.3 g citrulline — check which one the label counts.
Fatty acid included for body-composition support.
Watch out: Human results are small and inconsistent; GI upset at higher doses.
Highly branched carbohydrate that empties from the stomach fast for intra-workout fuel without heaviness.
Watch out: Only useful for long or glycogen-depleting sessions; it is calories.
Cocoa flavanols measurably improve blood-vessel dilation.
Watch out: Only high-flavanol standardised extracts count.
Included in some formulas; no established clinical effect on its own.
Whole coffee-fruit extract shown in small studies to raise BDNF.
Watch out: Almost entirely brand-funded research.
The most proven sports supplement there is: more strength, more reps, more lean mass over time.
Watch out: Works by saturation, so daily consistency beats pre-workout timing. Any form beyond monohydrate is a premium for no proven gain.
Mild diuretic used for a temporary 'dry' look.
Watch out: Water loss only — not fat loss.
Marketed for IGF-1 and recovery.
Watch out: Human evidence shows no meaningful benefit.
Caffeine bonded to malic acid — same effect, slightly slower release and gentler on the stomach.
Watch out: 266 mg of it = 200 mg caffeine. Labels often list the full weight to look bigger.
Ancient peat + apple extract claimed to raise the body's own ATP production.
Watch out: Small studies, mostly manufacturer-funded.
Branded botanical blend included for vasodilation and blood-flow feel.
Watch out: Included for pumps, but there is no established clinical effect on its own — the evidence is brand-run and preliminary.
Included in some formulas; no established clinical effect on its own.
Included in fat burners for thermogenesis and appetite control.
Watch out: Effects come from rodent studies; no established clinical effect in humans.
Digestion-resistant fibre used for satiety and gut health.
Watch out: Underdosed in most fat burners.
Branded botanical blend included to raise nitric oxide and blood flow.
Watch out: One manufacturer-run trial; no independent replication.
Included in some formulas; no established clinical effect on its own.
Coleus extract with mixed data on body composition and testosterone.
Watch out: Results have not replicated well.
Included for calm focus, relaxation and sleep support.
Watch out: Barely crosses the blood–brain barrier, so oral GABA has no established clinical effect on brain GABA levels.
Generic galangal used as a non-stim alertness ingredient.
Watch out: Unstandardised extracts are not equivalent to the branded versions.
Included as an appetite and fat-storage blocker.
Watch out: The largest human trials found no meaningful weight loss — no established clinical effect.
Precursor that raises the body's own carnitine levels over time.
Watch out: Notorious for heavy sweating; effect takes weeks.
Soluble fibre that swells in the stomach for genuine fullness.
Watch out: Needs a large volume of water — a few hundred mg in a capsule blend does nothing.
Included for recovery, gut health and immune support around hard training.
Watch out: In healthy, well-fed lifters there is no established clinical effect on strength or muscle gain.
Pulls water into muscle for fuller pumps and better hydration in long or hot sessions.
Watch out: Clumps badly in tubs; needs plenty of water or it can cause bloating.
Activates brown fat, raising calorie burn slightly in human trials.
Watch out: Effect size is small — worth a few dozen calories a day.
Polyphenols that support nitric oxide and vascular health.
Watch out: More of a long-term vascular ingredient than an acute pump driver.
Included to slow the breakdown of stimulants and extend their effect.
Watch out: Grapefruit compounds interfere with drug metabolism; no established clinical effect on fat loss.
Included for chlorogenic acid, which slows carbohydrate absorption; also a mild caffeine source.
Watch out: The famous early trials were retracted — expect a very small effect at best.
Slows carbohydrate absorption and slightly reduces fat gain.
Watch out: The famous early trials were retracted; expect a small effect at best.
Included in some formulas; no established clinical effect on its own.
Modestly raises daily calorie burn and fat oxidation, especially paired with caffeine.
Watch out: Very high doses have been linked to liver stress in rare cases.
A caffeine source with slower release thanks to the seed's tannins.
Watch out: Add its caffeine yield to the label total — 500 mg guarana can be 110 mg caffeine.
Naturally caffeinated Amazonian leaf — a smoother caffeine source with polyphenols alongside it.
Watch out: It is a caffeine source; add its yield to the total caffeine on the label.
Included in fat burners for thyroid and metabolic support.
Watch out: Human trials show no reliable fat loss, and it can cause rash and GI upset.
Temporarily blunts sweet taste and may reduce sugar cravings.
Watch out: Most data is small and short.
Light adrenergic stimulant marketed for clean energy and focus.
Watch out: Almost no human research; treat as a feel effect, not a proven one.
Traditional circulatory tonic used for vasodilation.
Watch out: Cardiac drug interactions; low doses in formulas do little.
A sodium source with trace minerals; functionally the same as salt.
Watch out: The 'trace minerals' are present in nutritionally irrelevant amounts.
Slows the breakdown of other stimulants, in theory extending their effect.
Watch out: Oral human evidence is essentially absent.
Slows acetylcholine breakdown, extending focus and mind–muscle feel.
Watch out: Long half-life — daily use is discouraged; cycle it.
Included in some formulas; no established clinical effect on its own.
Included in some formulas; no established clinical effect on its own.
Prebiotic fibre included for fullness and gut bacteria support.
Watch out: Causes gas and bloating in a lot of people; doses in blends are usually far too small.
African mango seed extract studied for weight and waist reduction.
Watch out: Positive trials come from a single research group.
Traditional diuretic in de-bloating formulas.
Watch out: Same caveat: this is water weight.
Shuttles fat into the mitochondria and reduces muscle damage; recovery benefits are the better-supported ones.
Watch out: Muscle levels only rise with weeks of daily use, ideally with carbohydrate.
Mushroom extract studied for nerve growth factor and mild cognitive support.
Watch out: Doses in pre-workouts are far below trial levels and often mycelium-on-grain.
Supports muscle function, sleep quality and energy metabolism; many people run low.
Watch out: Oxide form is poorly absorbed and can loosen the bowels.
Included for appetite and waist reduction (the African mango story).
Watch out: Positive trials all come from one research group; no independent confirmation.
Fast-hitting theacrine relative used for a quick front-end kick to the energy curve.
Watch out: Short-lived on its own and thin human data; almost always needs caffeine to matter.
Exercise-mimicking metabolite linked to fat oxidation and browning of fat tissue.
Watch out: No completed human weight-loss trials.
Included in some formulas; no established clinical effect on its own.
More soluble tyrosine form used to save label space.
Watch out: Converts to tyrosine poorly — gram for gram it is weaker than plain L-tyrosine.
The same coffee-fruit extract under its other trade name.
Watch out: Same limited, brand-funded evidence base.
Branded stimulant-nootropic blend included for a sharper, more euphoric energy feel.
Watch out: Proprietary blend with no published human data — no established clinical effect on its own.
B-vitamin used in energy metabolism; the flush is a side effect, not a benefit.
Watch out: Above ~35 mg causes intense skin flushing.
Converts to nitric oxide directly — proven to lower the oxygen cost of exercise and boost endurance.
Watch out: Antibacterial mouthwash blocks the conversion pathway.
Stabilised arginine that genuinely raises blood flow, with some cognition data too.
Watch out: Effects build over about a week of daily use.
Nitrosigine with added inositol, studied for reaction time and cognitive performance in gamers.
Watch out: Brand-funded trials; also raises blood flow, so it double-counts with other arginine sources.
Included as an antioxidant polyphenol with mild blood-pressure and blood-flow support.
Watch out: A minor contributor at the doses used in supplements.
Antioxidant polyphenol with mild blood-pressure and blood-flow support.
Watch out: Minor contributor in a pre-workout.
Included in some formulas; no established clinical effect on its own.
Adaptogen with modest evidence for reduced mental fatigue and better perceived energy.
Watch out: Only standardised extracts perform; effects build over weeks.
Included in some formulas; no established clinical effect on its own.
Included in some formulas; no established clinical effect on its own.
Included in some formulas; no established clinical effect on its own.
Lentil-peptide alternative to VasoDrive for vasodilation.
Watch out: Very new; one brand-run study.
Works with sodium to maintain fluid balance and normal muscle contraction.
Watch out: Doses in supplements are small by regulation.
Included in some formulas; no established clinical effect on its own.
Better-absorbed resveratrol relative with antioxidant and vascular effects.
Watch out: Mostly preclinical data.
Popular fat-burner filler.
Watch out: No human evidence of fat loss at any realistic dose.
Included in some formulas; no established clinical effect on its own.
Potent alpha-2 blocker used in fat burners to free up stubborn fat stores.
Watch out: The most common cause of anxiety, nausea and racing heart in a fat burner. Start very low.
Antioxidant polyphenol studied for vascular and metabolic health.
Watch out: Poorly absorbed; human results are inconsistent.
Adaptogen that reduces mental fatigue and perceived effort during long or stressful sessions.
Watch out: Only standardised extracts perform; effect is anti-fatigue, not stimulation.
Seven plant extracts shown in one study to raise nitric oxide by ~230% from a low baseline.
Watch out: A percentage rise from a small baseline is still a small absolute change.
Reduces snacking and emotional eating; mild mood lift.
Watch out: Works on appetite behaviour, not metabolism.
Included in some formulas; no established clinical effect on its own.
Yerba santa extract branded for smooth, extended energy.
Watch out: Branded ingredient with minimal independent human data.
Mood-lifting botanical (kanna) used for a euphoric, calm-focus feel.
Watch out: Do not combine with SSRIs or MAOIs.
Branded blend claimed to clear senescent cells and improve endurance recovery.
Watch out: Small manufacturer-funded trials.
Citrus polyphenol blend with trial data on fat mass and waist reduction over 12 weeks.
Watch out: Requires the full daily dose for weeks; brand-funded trials.
Key electrolyte for fluid balance, blood volume and pumps, especially when you sweat heavily.
Watch out: Useful, not scored as an active — most diets already supply plenty.
Mild adrenaline-like stimulant that nudges up calorie burn and appetite suppression.
Watch out: Raises heart rate and blood pressure, especially with high caffeine. Banned in some sports.
Supports endurance, cell hydration and a calmer stimulant feel.
Watch out: Cheap, so it is often the bulk of an undisclosed 'energy blend'.
Caffeine-like energy and mood lift with far less tolerance build-up over weeks.
Watch out: Slower onset (~1 h) and long duration; stacks with caffeine rather than replacing it.
Caffeine-like energy and mood lift with much less tolerance build-up over weeks.
Watch out: Slow onset (~1 h) and long duration; stacks with caffeine rather than replacing it.
Takes the anxious edge off caffeine and sharpens calm, sustained focus.
Watch out: Best at roughly a 1:1 or 2:1 ratio with caffeine.
Mild cocoa stimulant that widens blood vessels — smoother, longer energy and a small pump effect.
Watch out: Very weak alone; useful mainly to take the edge off caffeine.
Raw material for dopamine and noradrenaline; protects focus under stress, heat and fatigue.
Watch out: Most pre-workouts use a fraction of the studied dose.
Milk-derived peptides that relax blood vessels and support healthy blood pressure.
Watch out: Dairy-derived; small trials only.
Mucuna pruriens — natural L-Dopa source used for mood and drive.
Watch out: Chronic use may downregulate dopamine; cycle it.
Periwinkle alkaloid used to increase cerebral blood flow.
Watch out: Prescription-grade compound in some countries; sparse safety data as a supplement.
Included in some formulas; no established clinical effect on its own.
Included in some formulas; no established clinical effect on its own.
Coated, slow-release caffeine used to stretch energy over several hours rather than one spike.
Watch out: Only 60% is caffeine, and the tail can interfere with sleep later than plain caffeine.
Included as a starch blocker to reduce calories absorbed from carbohydrates.
Watch out: Small, short trials with mixed results; gas and bloating are common.
Boosts fat release from stubborn areas, best studied fasted.
Watch out: Anxiety, jitters and elevated blood pressure are common. Food blunts the effect.
Essential mineral for immunity and hormone production.
Watch out: Chronic high doses block copper absorption.
Doses shown are per day unless noted, and reflect what human trials used — not what a label suggests. An ingredient only earns credit in our score when a product hits that dose. Nothing here is medical advice.