This site provides general information only and is not medical advice. Talk to a qualified healthcare professional before starting any supplement, especially if you are pregnant, take prescription medication, or have a medical condition.

Some links on this page are affiliate links. If you buy through them, we earn a commission at no extra cost to you. It does not change which products we recommend — see our methodology and full disclosure.

Ingredient

Caffeine

Strong

A well-characterized adenosine antagonist with a clearly studied dose range.

How it works

Blocks adenosine receptors and increases catecholamine release, supporting alertness and short-window output.

Evidence

ISSN position stand and a systematic review of time-trial endurance studies establish ergogenic effects at approximately 3-6 mg/kg body weight, with diminishing returns above 9 mg/kg.

Studies

Goldstein et al., J Int Soc Sports Nutr, 2010 (ISSN position stand)
Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (~3-6 mg/kg) and overall does not result in further enhancement at higher dosages (≥9 mg/kg).
PubMed 20205813 ↗
Ganio et al., J Strength Cond Res, 2009
Systematic review of 21 studies (33 caffeine treatments) found 3.2 ± 4.3% improvement in time-trial endurance at moderate doses (3-6 mg/kg body mass).
PubMed 19077738 ↗

One ingredient, one study, one product worth your money.

Weekly. No fluff. Unsubscribe in one click.