Taurine
Free-form L-taurine powder or capsules, USP grade; no standardisation needed
Moderate
Some good studies, not many repeats
Two meta-analyses agree in direction, but the endurance pool (10 studies) is heterogeneous with a CI approaching zero, and the −3.6 bpm heart-rate effect comes largely from clinical cohorts (heart failure, hypertension, diabetes), not healthy trained adults. Not yet strong for the wearable claim.
Across 20 studies it gave a small-to-moderate boost to endurance and lowered resting heart rate by about 3 to 4 beats per minute.
Improves endurance performance by a small-to-moderate margin (Hedges' g = 0.40, 95% CI 0.12 to 0.67) and lowers resting heart rate by 3.6 bpm (95% CI −6.04 to −1.11) across 20 RCTs.
Osmolyte and calcium-handling modulator in muscle and myocardium; stabilises sarcoplasmic reticulum Ca²⁺ release, buffers oxidative stress and supports thermoregulation — the cycling trial showed lower core temperature at 4 g without any change in heart rate or RPE.
Endurance athletes training in heat and humidity, and people starting from an elevated resting heart rate or blood pressure. Low-taurine diets (strict vegan) plausibly respond more, though this has not been tested directly.
We compare each effect with how much that number normally swings from one night to the next. An effect smaller than the swing is real, but you will not see it in a week of data.
- Resting heart rateProbably visibleeffect: 3.58 bpmnormal swing: ±2.5 bpm
What to buy
- ✓Free-form L-taurine powder or capsules, USP grade; no standardisation needed
- ✓1–6 g/day; 3–4 g/day is the practical middle. In the dose-response cycling trial 4 g beat both 1 g and 6 g.
- ✓Third-party tested (USP, NSF, Informed Sport)
- ✕Proprietary blends that hide the dose per ingredient
- ✕Unstandardised extracts with no active-compound percentage
- · Generally well tolerated up to 6 g/day; loose stools and nausea are the main reports at the top of that range
- · Additive hypotension — meta-analysis found systolic BP −4.0 mmHg, so caution if already hypotensive or on antihypertensives
- · Very limited data in pregnancy, lactation and in people with reduced kidney function
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Free-form taurine, one gram per capsule, nothing else in the bottle. Three capsules a day lands on the 3–4 g that beat both 1 g and 6 g in the cycling trial.
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Four hundred capsules — at 3 g a day that is a four-month supply, which is longer than any test you will run.
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The highest-rated taurine here, hypoallergenic and free of the fillers that show up in cheaper capsules.
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See all on AmazonEvery result, next to the line that means no effect
Each diamond is a study's best estimate. The thin line shows how sure the study was: the shorter the line, the more certain the result.
- Resting heart ratebpm · Nutrition Journal 2024 (20 RCTs, n=808); noise_sd = estimated within-person night-to-night SD of wearable RHR−3.58−6.04 … −1.11
- Endurance performanceHedges' g · Waldron et al., Sports Medicine 2018+0.40+0.12 … +0.67
- Systolic blood pressuremmHg · Nutrition Journal 2024−4.00−7.29 … −0.71
- Cycling time to exhaustion (4 g)seconds vs placebo · Li et al., Frontiers in Nutrition 2025 (812.4 s vs 702.4 s, p=0.031)+110.0[not given]
Each unit gets its own scale, so numbers are never mixed on one line. When a study gave no range, we leave it blank instead of inventing one.
3 studies over 7 years
The studies
- 1.The Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-AnalysisSports Medicine · 2018 · meta-analysis · 10 experiments
Pooled Hedges' g = 0.40 (95% CI 0.12–0.67) for endurance; 0.43 (0.12–0.75) for time-to-exhaustion. Dose (1–6 g) and acute vs chronic did not moderate the effect.
- 2.Insights into the cardiovascular benefits of taurine: a systematic review and meta-analysisNutrition Journal · 2024 · meta-analysis · 20 experiments · n = 808
Heart rate −3.58 bpm (−6.04 to −1.11), SBP −4.00 mmHg (−7.29 to −0.71), DBP −1.44 (−2.48 to −0.39), LVEF +4.98% (1.56 to 8.41). Doses 1.5–6 g/day over 5–90 days.
- 3.Dose-response relationship of taurine on endurance cycling performance under hot and humid conditionsFrontiers in Nutrition · 2025 · crossover · 1 experiments · n = 16
4 g raised time to exhaustion to 812 ± 91 s vs 702 ± 83 s placebo (p=0.031) and lowered core temperature; 1 g and 6 g did not reach significance. No effect on heart rate or RPE.
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