Compound library
Understand what people are taking.
Browse medicines, supplements, herbs, and health foods. Each profile brings community reports and linked research into one clear view.
Browse medicines, supplements, herbs, and health foods. Each profile brings community reports and linked research into one clear view.
Stimulant that blocks the brain's adenosine ('tiredness') receptors, found in coffee, tea, energy drinks and pre-workout products. Meta-analyses of placebo-controlled trials show small but consistent gains in endurance (time trials about 2-3% faster at 3-6 mg per kg of body weight), in strength and power, and in attention and reaction time, with the biggest effects after sleep loss. The costs are just as well documented: it shortens and lightens sleep, raises blood pressure, and can trigger anxiety or panic in people prone to it. EFSA considers up to 400 mg a day from all sources, and no more than 200 mg at once, safe for healthy adults.
14 of 17 results reported a benefit, from 3 published studies.
3 studies, including a review of trials
These are the figures the studies reported, not a prediction for any one person. Where several studies measured the same thing in the same unit, we show a simple average and say so. Every individual result is listed below.
See every resultMuscular force production. Influenced by training, protein intake, hormones, and neuromuscular efficiency.
Also known as: Caffeine anhydrous, 1,3,7-Trimethylxanthine
Every published result for this pair, extracted and audited.
These charts group published studies by what they reported and how they were run — green marks studies that reported a benefit for this pairing. Tiers run from pooled analyses of many trials (strongest) to one-off observational reports.
Direction of reported outcomes for Caffeine in strength.
Study designs behind these findings.
Hand-selected PubMed studies, linked to the originals.
Be the first to share what you noticed with Caffeine for strength. Why counts start empty.
Every measured outcome, one row per finding - numbers exactly as reported.
| Study | Design | n | Duration | Outcome measured | Reported result | Direction |
|---|---|---|---|---|---|---|
| PMID 31643020 2020 | Meta-analysis | - | - | Mean velocity | 0.80 SMD (95% CI: 0.48-1.12; p < 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Movement velocity (overall) | 0.62 SMD (95% confidence interval [CI]: 0.39-0.84; p < 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Movement velocity in lower-body exercises | 0.82 SMD (95% CI: 0.42-1.23; p < 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Movement velocity in upper-body exercises | 0.59 SMD (95% CI: 0.37-0.82; p < 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Movement velocity with high loads | 0.70 SMD (95% CI: 0.33-1.07; p < 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Movement velocity with low loads | 0.78 SMD (95% CI: 0.41-1.14; p < 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Movement velocity with moderate loads | 0.58 SMD (95% CI: 0.25-0.91; p = 0.001) | Benefit |
| PMID 31643020 2020 | Meta-analysis | - | - | Peak velocity | 0.41 SMD (95% CI: 0.08-0.75; p = 0.014) | Benefit |
| PMID 30217692 2019 | Meta-analysis | - | - | Isokinetic muscular strength (overall) | 0.16 (95% CI=0.06, 0.26; p=0.003) | Benefit |
| PMID 30217692 2019 | Meta-analysis | - | - | Isokinetic strength of other, smaller muscle groups | reported qualitatively (p=0.092) | No benefit |
| PMID 30217692 2019 | Meta-analysis | - | - | Knee extensor isokinetic strength | 0.19 (95% CI=0.06, 0.32; p=0.004) | Benefit |
| PMID 30217692 2019 | Meta-analysis | - | - | Knee extensor isokinetic strength at angular velocities 60°/s and 180°/s | reported qualitatively | Benefit |
| PMID 30217692 2019 | Meta-analysis | - | - | Knee extensor isokinetic strength at angular velocity 30°/s | reported qualitatively (p=0.193) | No benefit |
| PMID 29527137 2018 | Meta-analysis | - | - | lower body strength | 0.15 SMD (95% CI: -0.05, 0.34; p = 0.147) | No benefit |
| PMID 29527137 2018 | Meta-analysis | - | - | maximal muscle strength | 0.20 SMD (95% confidence interval [CI]: 0.03, 0.36; p = 0.023) | Benefit |
| PMID 29527137 2018 | Meta-analysis | - | - | muscle power | 0.17 SMD (95% CI: 0.00, 0.34; p = 0.047) | Benefit |
| PMID 29527137 2018 | Meta-analysis | - | - | upper body strength | 0.21 SMD (95% CI: 0.02, 0.39; p = 0.026) | Benefit |