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Head-to-head evidence comparison — which supplement is right for you?
Caffeine vs Theacrine: Caffeine has the stronger overall evidence (9.5 vs 5.5/10); they're alternatives for boost daily energy — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Caffeine wins 2 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 Theacrine have evidence — compare verdict strength side-by-side.
100-200mg
Morning, About 60 minutes before exercise
Pill/capsule for precise dosing
100-200mg daily
Morning or early afternoon, 30-60 minutes before focus work, Pre-workout
TeaCrine (branded theacrine)
and 3 more not shown
Additive stimulant effects; combining raises the risk of overstimulation, elevated heart rate/blood pressure, jitteriness and insomnia. Reduce doses of both when combining.
Discuss with your healthcare provider before combining.
15-45 minutes
30-60 minutes
30-60 minutes
30-60 minutes
30-60 minutes, lasts 4-6 hours
30-60 minutes
30-60 minutes
30-60 minutes
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).
A caffeine and theacrine combination improves cognitive performance in tactical personnel under physically fatiguing conditions
Journal of the International Society of Sports Nutrition (2025) · Rct · n=20
In the Object Hit & Avoid task, CAF and CTC significantly improved task accuracy (p < 0.01) while reducing omission (p < 0.01) and commission errors (p < 0.01) compared to PLA.
Theacrine as a novel ergogenic aid: impact on canoe sprint performance
Journal of the International Society of Sports Nutrition (2025) · Rct · n=20
Twenty highly trained male canoe sprint athletes completed a randomised crossover of placebo, caffeine, theacrine, and caffeine plus theacrine.
Uncovering the effects and mechanisms of tea and its components on depression, anxiety, and sleep disorders: A comprehensive review
Food research international (Ottawa, Ont.) (2024) · Review
A narrative overview of animal, clinical, and epidemiological studies on tea and its components, not a systematic review with pooled results.
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 5.5/10) and wins in 2 of 3 categories.
For boost daily energy, Caffeine has a higher relevance score (98 vs 35).
Additive stimulant effects; combining raises the risk of overstimulation, elevated heart rate/blood pressure, jitteriness and insomnia. Reduce doses of both when combining. Discuss with your healthcare provider before combining. Consult a healthcare provider for personalized advice.
The honest tier list — proven staples vs situational vs mostly marketing. The hub the other guides feed into.
Tired? Why most "energy" pills only work if they fix a deficit — and how to find yours first.
Caffeine+L-theanine works; bacopa needs weeks; most "brain pills" are hype. The honest tier list.
Caffeine, citrulline, beta-alanine, creatine — the ingredients that work, at clinical doses (vs fairy dusting).
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.