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Head-to-head evidence comparison — which supplement is right for you?
Caffeine vs Yohimbe: Caffeine has the stronger overall evidence (9.5 vs 5/10); take care combining them — there's a flagged interaction. Take the 60-second quiz for a pick tailored to your goals.
Caffeine wins 3 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Probably helps
5 of 9 studies with measurable effects showed benefit.
Top outcomes
Verdict
Too few graded studies
Top outcomes
Shared outcomes (2)
Outcomes where both Caffeine and Yohimbe have evidence — compare verdict strength side-by-side.
100-200mg
Morning, About 60 minutes before exercise
Pill/capsule for precise dosing
Standardized yohimbine ~5-10mg (or ~0.2mg/kg) up to 1-2x daily; start at the lowest dose. Raw yohimbe bark is discouraged due to unpredictable content. The one cited trial that states a dose gave a single 10 mg dose.
Morning
Standardized yohimbine HCl (known dose)
and 3 more not shown
and 2 more not shown
Significantly increased cardiovascular stimulation and anxiety risk
AVOID combination due to cardiovascular risk.
15-45 minutes
30-60 minutes
30-60 minutes
30-60 minutes
2-8 weeks
Acute
Acute
Throughout use
Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis
Nutrients (2020) · Meta analysis
A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD).
The effects of caffeine intake on weight loss: a systematic review and dos-response meta-analysis of randomized controlled trials
Critical reviews in food science and nutrition (2019) · Meta analysis · n=606
Thirteen RCTs with 606 participants were included in the meta-analyses.
Effect of Caffeine and Nitrates Combination on Exercise Performance, Heart Rate and Oxygen Uptake: A Systematic Review and Meta-Analysis
Nutrients (2024) · Meta analysis · n=95
The meta-analysis revealed that caffeine and nitrates supplementation (CAF+nitrates) did not enhance performance in time trials (TTs) over the CAF alone (g = -0.06; 95% CI = -0.46 to 0.35; p = 0.78) or nitrates alone (g = 0.29; 95% CI = -0.12 to 0.70; p = 0.17).
Yohimbine for erectile dysfunction: a systematic review and meta-analysis of randomized clinical trials.
The Journal of urology (1998) · Meta analysis
Yohimbine significantly more effective than placebo for ED
Erectile dysfunction.
BMJ clinical evidence (2011) · Review
Yohimbine has modest ED efficacy
Pharmacological interventions in primary or secondary male anorgasmia: A systematic review.
Actas urologicas espanolas (2025) · Systematic review
Yohimbine among agents assessed for anorgasmia
Exercise trials dose caffeine by body weight, so this curve is in mg per kg, taken about an hour before exercise. A meta-analysis of 46 placebo-controlled trials found a small but clear endurance benefit at moderate doses of 3 to 6 mg/kg (PMID 29876876), and the ISSN position stand reports consistent benefits across that range, a possible minimum as low as 2 mg/kg, and a high rate of side effects at 9 mg/kg with no extra benefit (PMID 33388079), so the curve is flat above 3 mg/kg while side effects rise. 4.5 mg/kg raised time to exhaustion and VO2max in 23 elite endurance athletes (PMID 34033621), and 3 mg/kg raised muscular endurance and strength in 29 resistance-trained adults (PMID 39246027). No single optimal dose is established, and no safe ceiling is plotted: the pregnancy and lactation limits in the safety section apply to total daily intake.
AI-estimated from published studies. Interpret as directional guidance.
Caffeine has a higher evidence score (9.5/10 vs 5/10) and wins in 3 of 3 categories.
For manage weight, Caffeine has a higher relevance score (60 vs 42).
Caution: Significantly increased cardiovascular stimulation and anxiety risk AVOID combination due to cardiovascular risk. Always consult a healthcare provider before combining these supplements.
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The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.