Caffeine
What it is
Stimulant that modestly raises energy expenditure and fat oxidation and can blunt appetite short-term.
What the evidence says
A 2019 dose-response meta-analysis (Tabrizi et al., 13 RCTs, 606 participants) found caffeine intake reduced weight, BMI and fat mass, with each doubling of dose linked to roughly 22%, 17% and 28% greater reductions respectively. Effects are real but small, often studied alongside other compounds, and tolerance plus cardiovascular/sleep side effects limit higher doses. Evidence supports a modest, dose-dependent effect rather than meaningful standalone weight loss.
Commonly 100-400 mg/day in trials; effects appear dose-dependent, but tolerance develops and >400 mg/day raises side-effect risk.
Educational summary of doses studied — not a recommendation. Talk to a clinician before starting any supplement.
Sources (1)
- The effects of caffeine intake on weight loss: a systematic review and dose-response meta-analysis of randomized controlled trials — Critical Reviews in Food Science and Nutrition (2019)
Educational summary of published research, checked against primary sources and linked inline. Not medical advice; supplements are not FDA-evaluated to treat disease. See our editorial policy.