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Head-to-head evidence comparison — which supplement is right for you?
Caffeine vs Casein Protein: Casein Protein has the stronger overall evidence (7.5 vs 9.5/10); they're alternatives for speed up recovery — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Casein Protein wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
29 of 35 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
4 of 4 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Caffeine and Casein Protein have evidence — compare verdict strength side-by-side.
100-200mg
Morning, 30-60 minutes before exercise
Pill/capsule for precise dosing
30-40g before bed
30-60 minutes before bed, Between meals for sustained protein
Micellar Casein powder
15-45 minutes
30-60 minutes
30-60 minutes
30-60 minutes
Overnight
2-4 weeks
4-8 hours
Always
Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis
Nutrients (2020) · Meta analysis · n=2020
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).
Effects of supplementation with milk protein on glycemic parameters: a GRADE-assessed systematic review and dose-response meta-analysis
Nutrition journal (2023) · Meta analysis · n=1851
The findings of this study suggest that supplementation with MP may improve glycemic control in adults by reducing the values of fasting insulin, FBG, and HOMA-IR.
Pre-Sleep Casein Supplementation, Metabolism, and Appetite: A Systematic Review
Nutrients (2021) · Systematic review · n=11
However, it remains unclear what the effect of this nutritional strategy is on non-muscular parameters such as metabolism and appetite in both healthy and unhealthy populations.
Pre-Sleep Protein Ingestion to Improve the Skeletal Muscle Adaptive Response to Exercise Training
Nutrients (2016) · Review
Protein ingested prior to sleep is effectively digested and absorbed, and thereby stimulates muscle protein synthesis rates during overnight recovery.
Based on multiple meta-analyses showing 3-6mg/kg optimal dosing. Performance benefits plateau around 200-300mg with increased jitteriness at higher doses.
Based on systematic review (n=387) showing pre-sleep casein enhances training adaptations and increases muscle fiber size. Optimal dose identified as 30-40g. Limited to pre-sleep timing and requires concurrent exercise training.
AI-estimated from published studies. Interpret as directional guidance.
Casein Protein has a higher evidence score (7.5/10 vs 9.5/10) and wins in 2 of 3 categories.
For speed up recovery, Casein Protein has a higher relevance score (85 vs 45).
No known interactions between Caffeine and Casein Protein have been documented in our database. However, always consult a healthcare provider before combining 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.