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Head-to-head evidence comparison — which supplement is right for you?
Caffeine vs Exogenous Ketones: Caffeine has the stronger overall evidence (9.5 vs 4/10); they work on different things and are often used together, not either/or. 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
Likely helps
19 of 23 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mostly mechanism / observational
Top outcomes
Shared outcomes (2)
Outcomes where both Caffeine and Exogenous Ketones have evidence — compare verdict strength side-by-side.
100-200mg
Morning, 30-60 minutes before exercise
Pill/capsule for precise dosing
Ketone ester: 25 g per dose is the standard clinical unit. Salts: no established effective dose — the mineral load caps them below useful ketosis
any
Ketone monoester if you want actual ketosis — the salts largely cannot get there
Caffeine carries the evidence here; ketones are an experimental adjunct whose endurance-performance effect is null on meta-analysis, and ketone ester measurably reduced 30-min time-trial power.
If you are combining these for performance, expect caffeine to be doing the work. Do not add a ketone ester before a short high-intensity effort.
15-45 minutes
30-60 minutes
30-60 minutes
30-60 minutes
30-60 minutes
Acute
Acute to 2 weeks
Acute
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).
On the Metabolism of Exogenous Ketones in Humans.
Front Physiol (2017) · Crossover · n=15
Peak D-BHB: ketone ester 2.8 mM vs ketone salt 1.0 mM at matched dose (P<0.001); both cleared in 3-4 hours
Acute Ingestion of Ketone Monoesters and Precursors Do Not Enhance Endurance Exercise Performance: A Systematic Review and Meta-Analysis.
Int J Sport Nutr Exerc Metab (2022) · Meta analysis
No significant performance effect: Hedges g = 0.136 (95% CI -0.195 to 0.467; p=0.419)
Exogenous Ketosis Impairs 30-min Time-Trial Performance Independent of Bicarbonate Supplementation.
Med Sci Sports Exerc (2021) · Rct · n=14
30-min time-trial power was 1.5% WORSE with ketone ester (main effect p=0.03), despite raising D-BHB to 3-4 mM
Based on multiple meta-analyses showing 3-6mg/kg optimal dosing. Performance benefits plateau around 200-300mg with increased jitteriness at higher doses.
AI-estimated from published studies. Interpret as directional guidance.
Caffeine has a higher evidence score (9.5/10 vs 4/10) and wins in 2 of 3 categories.
For sharpen focus, Caffeine has a higher relevance score (90 vs 40).
Caffeine and Exogenous Ketones may work well together: Caffeine carries the evidence here; ketones are an experimental adjunct whose endurance-performance effect is null on meta-analysis, and ketone ester measurably reduced 30-min time-trial power. If you are combining these for performance, expect caffeine to be doing the work. Do not add a ketone ester before a short high-intensity effort.
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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.