Taurine (2-aminoethanesulfonic acid) is a small sulfur-containing compound that is a normal constituent of the body and of the human diet. It is often called an amino acid, but it is not used to build proteins. The body makes some taurine from methionine and cysteine, and the rest comes from animal foods. It is best known as an ingredient of energy drinks and as a stand-alone supplement marketed for endurance, recovery and, since 2023, “longevity.”
The most important fact about the longevity claim is this: a 2023 Science paper reported that taurine supplements extended lifespan in mice and improved health markers in monkeys, but no human trial has tested taurine against aging. Two later human studies found that blood taurine does not fall with age in people. In humans, the best-supported findings are modest: a small benefit for endurance performance and small reductions in blood pressure, blood glucose and triglycerides in meta-analyses of short trials.
This page summarizes what clinical trials, meta-analyses and the European Food Safety Authority (EFSA) report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Class | Sulfur-containing amino sulfonic acid; not incorporated into proteins |
| Sources | Made in the body from methionine and cysteine; dietary intake from animal foods; absent from vegan diets |
| Route | Oral (supplements, energy drinks, food) |
| Studied doses in trials | 0.5–6 g/day in meta-analyzed trials; 9–12 g/day in a MELAS trial |
| Half-life (oral, 4 g) | 1.0 ± 0.3 h; peak at 1.5 h (Ghandforoush-Sattari 2010) |
| Energy-drink content (EFSA assumption) | 4,000 mg/L in a 250 mL can |
| EFSA view | Exposure from energy drinks “not of safety concern” (2009) |
| Drug approval | Approved in Japan since 2019 to prevent stroke-like episodes in MELAS |
| WADA status | Not on the WADA 2026 Prohibited List |
What it is
Taurine’s formula is a two-carbon chain with an amino group at one end and a sulfonic acid group at the other. That sulfonic acid group, instead of the carboxylic acid group of ordinary amino acids, is why it is not built into proteins. It exists in cells as a free molecule.
The liver and brain make taurine from methionine or cysteine, via cysteic acid or hypotaurine (Ghandforoush-Sattari et al., J Amino Acids 2010). Its known roles in the body include:
- conjugating bile acids in the liver (forming taurine-conjugated bile salts);
- regulating cell volume as an osmolyte (a molecule that balances water across cell membranes);
- stabilizing membranes and modulating calcium movement;
- neutralizing hypochlorous acid made by white cells, by forming taurochloramine.
Diet matters because human synthesis is limited. EFSA estimated mean taurine intake from omnivore diets at no more than 400 mg/day (EFSA ANS Panel 2009). In a UK study, taurine was absent from vegan diets. Vegans’ urinary taurine was less than half that of omnivores, but their plasma levels were only slightly lower (Rana and Sanders, Br J Nutr 1986). This suggests the body conserves taurine when intake is low.
Pharmacokinetics
The only full oral pharmacokinetic study in healthy people gave 4 g of taurine to eight fasting men (Ghandforoush-Sattari et al., J Amino Acids 2010):
| Parameter | Value |
|---|---|
| Baseline plasma taurine | ≈0.04 mmol/L (range 0.03–0.06) |
| Time to peak | 1.5 ± 0.6 h (range 1–2.5 h) |
| Peak concentration | 86.1 ± 19.0 mg/L (0.69 ± 0.15 mmol/L) |
| Elimination half-life | 1.0 ± 0.3 h |
| Clearance/bioavailability (Cl/F) | 21.1 ± 7.8 L/h |
| Return to baseline | 6–8 h |
Human data suggest taurine is absorbed by active transport in the gut wall. In rats given radiolabeled taurine, it was rapidly absorbed, distributed to tissues and excreted unchanged in urine, while elimination from inside cells was slow. Fourteen days of dosing did not raise total brain taurine in rats (EFSA ANS Panel 2009). The short plasma half-life therefore describes how fast an extra dose leaves the blood, not how fast tissue stores turn over.
Approved medical use
Taurine is mainly sold as a supplement and food ingredient. In Japan, high-dose taurine has been approved and covered by public insurance since 2019 to prevent stroke-like episodes in MELAS (Sunada, Brain Nerve 2023). MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) is a rare mitochondrial disease. Its usual mutations prevent a taurine modification of a mitochondrial transfer RNA, which disrupts protein production in mitochondria.
The approval rests on a small trial. In an open-label, single-arm phase III study, 10 patients with recurrent stroke-like episodes took 9 or 12 g/day for 52 weeks (Ohsawa et al., J Neurol Neurosurg Psychiatry 2019):
| Outcome | Result |
|---|---|
| Complete prevention of stroke-like episodes | 60% of patients (95% CI 26.2–87.8%) |
| At least 50% fewer episodes | 80% (95% CI 44.4–97.5%) |
| Annual relapse rate | 2.22 before vs 0.72 on taurine (P = 0.001) |
| Severe adverse events tied to taurine | None |
A 2026 European expert consensus on MELAS concluded that the efficacy of taurine and other supplements remains unproven and needs validation in clinical trials (Mancuso et al., Eur J Neurol 2026). The trial had no control group, so the evidence is promising but limited.
What the research shows
Aging: the 2023 Science paper (mostly animal data)
Singh and colleagues reported that circulating taurine falls with age and that restoring it extends healthy life in several species (Singh et al., Science 2023; full text). The main results by species:
| Model | Design | Reported result |
|---|---|---|
| Mice (C57Bl/6J) | 1,000 mg/kg/day orally from 14 months of age until death | Median lifespan +10–12%; life expectancy at 28 months +18–25% in both sexes |
| Mice | Serum taurine at 4 vs 56 weeks of age | 132.3 vs 40.2 ng/mL |
| Rhesus monkeys (female, ≈15 years old) | 250 mg/kg/day for 6 months | 0.75 kg less weight gain; higher spine and leg bone density; fasting glucose −19%; lower AST/ALT and white cell counts |
| Monkeys | Serum taurine, 15- vs 5-year-olds | 85% lower in older animals |
| Worms | Taurine added to diet | Longer life |
| Humans (cross-sectional) | Serum taurine, elderly vs younger people | Over 80% lower in the elderly |
| Humans (EPIC-Norfolk, n = 11,966) | Associations, no supplementation | Higher taurine linked to lower BMI, waist-to-hip ratio and several age-related conditions |
| Humans (athletes and sedentary men) | Before vs after a graded cycling test | Taurine rose ≈1.16-fold after exercise |
Several points limit how far these results apply to people:
- The lifespan and healthspan effects are animal results. The monkey study measured health markers for 6 months, not lifespan, and included only females.
- The doses were large. The mouse dose was 1,000 mg/kg/day. The authors called the monkey dose of 250 mg/kg/day equivalent.
- The human evidence was correlational. No person in the paper received taurine. Lower taurine in older or sicker people does not show that low taurine causes aging.
- The authors themselves called for trials. They wrote that clinical trials in humans “seem warranted” to test the idea.
Aging: the follow-up human data
Two independent groups then tested the central premise, that taurine declines with age in humans.
| Study | Population | Finding |
|---|---|---|
| Fernandez et al., Science 2025 (NIA, NIH) | Three human cohorts in different countries, plus monkeys and mice; longitudinal and cross-sectional | Circulating taurine rose or stayed the same with age; links with health outcomes varied by cohort and species |
| Marcangeli et al., Aging Cell 2025 | 137 active and inactive men aged 20–93 | No association of serum taurine with age, muscle mass, strength, physical performance, insulin sensitivity or muscle mitochondrial function |
The NIH group concluded that falling taurine is not a universal feature of aging. In repeated samples over time, variation in taurine levels often exceeded the changes linked to age (NIH IRP, 2025). In the Canadian cohort, mean serum taurine was similar in active and inactive men (92.4 vs 96.9 μmol/L).
Does taurine slow aging in people? This is untested. The lifespan data come from mice and worms, and the monkey data cover 6 months of health markers. The human finding that started the idea, falling blood taurine with age, was not reproduced in larger human cohorts. No randomized trial has measured aging outcomes in humans taking taurine.
Endurance and exercise performance
Taurine is studied as an ergogenic aid (a performance enhancer), mostly in small crossover trials.
| Meta-analysis | Trials / participants | Doses | Effect |
|---|---|---|---|
| Waldron et al., Sports Med 2018 | 10 studies, endurance only | 1–6 g/day, single dose to 2 weeks | Hedges’ g 0.40 (95% CI 0.12–0.67); time-to-exhaustion g 0.43 |
| Deng et al., Scand J Med Sci Sports 2025 | 23 randomized trials, n = 308, single dose | Mostly 1–6 g | Overall g 0.25 (95% CI 0.10–0.39); GRADE certainty low to very low |
Hedges’ g is a standardized effect size, and the 2025 authors described the pooled effect as small to moderate. Both analyses found no dose-response within 1–6 g, and no difference between single doses and up to 2 weeks of use. The 2025 analysis found that several subgroup effects weakened when influential studies were removed. Its prediction intervals often included no effect, so the benefit may not replicate in every setting.
Energy drinks combine taurine with caffeine, which is itself ergogenic. A 2025 network meta-analysis of 12 studies suggested the combination did better than either alone for anaerobic capacity and reaction time, but the evidence base was small (Deng et al., J Int Soc Sports Nutr 2025).
Blood pressure and cardiometabolic markers
The best single trial randomized 120 people with prehypertension to 1.6 g/day taurine or placebo for 12 weeks (Sun et al., Hypertension 2016). Mean clinic blood pressure fell 7.2/4.7 mmHg on taurine vs 2.6/1.3 mmHg on placebo. Ambulatory 24-hour systolic pressure fell 3.8 vs 0.3 mmHg.
Meta-analyses of randomized trials report small improvements:
| Meta-analysis | Trials (n) | Outcome | Pooled effect vs control |
|---|---|---|---|
| Waldron et al., Curr Hypertens Rep 2018 | 7 studies (103) | Systolic / diastolic BP | ≈3 mmHg reduction in each |
| Tzang et al., Nutr Diabetes 2024 | 25 RCTs (1,024) | Systolic BP | −4.0 mmHg (95% CI −7.3 to −0.7) |
| Same | Same | Fasting glucose | −5.9 mg/dL (95% CI −10.7 to −1.0) |
| Same | Same | Triglycerides | −18.3 mg/dL (95% CI −25.6 to −11.0) |
| Same | Same | HDL cholesterol | No significant change |
| Nie et al., Nutr Rev 2026 | 34 RCTs | HbA1c | −0.21% (95% CI −0.37 to −0.05) |
| Same | Same | LDL cholesterol | −5.1 mg/dL (95% CI −8.4 to −1.8) |
| Same | Same | Systolic / diastolic BP | −4.4 / −2.5 mmHg |
Trial doses ranged from 0.5 to 6 g/day, for 5 days to 1 year. In people with diabetes specifically, a meta-analysis of 5 trials (209 participants) found lower HbA1c, fasting glucose and insulin resistance, but no effect on lipids, blood pressure or body composition (Tao et al., Food Chem (Oxf) 2022). Most included trials were small and short. These are changes in risk markers, not proven reductions in heart attacks, strokes or deaths.
Cognition
A 2025 meta-analysis of 7 randomized trials (402 participants) found no significant effect of taurine on cognitive scores (Cao et al., Int J Food Sci Nutr 2025).
Side effects and risks
Safety in trials
Taurine has a good safety record at studied doses. The meta-analyses above reported no significant excess of adverse effects vs control. A risk assessment of published human trials found strong evidence of no adverse effects at supplemental intakes up to 3 g/day. It set that as the “observed safe level” for healthy adults (Shao and Hathcock, Regul Toxicol Pharmacol 2008). Higher doses had been tested without harm, but the authors judged the data insufficient to confirm long-term safety above 3 g/day.
EFSA noted that clinical studies giving 3–6 g/day orally for up to one year, mostly in patients with serious illness, reported no adverse health effects (EFSA ANS Panel 2009). The MELAS trial at 9–12 g/day reported no severe adverse events tied to taurine, but it had only 10 patients.
EFSA’s assessment of taurine in energy drinks
In 2009, EFSA’s Panel on Food Additives and Nutrient Sources (ANS) assessed taurine as an energy-drink ingredient (EFSA ANS Panel 2009). It assumed 4,000 mg/L taurine in a 250 mL can and used older consumption data from the EU Scientific Committee on Food (SCF):
| Scenario (60 kg adult) | Taurine intake | Margin vs rat NOAEL of 1,000 mg/kg/day |
|---|---|---|
| Mean chronic intake (0.5 can/day) | 500 mg/day (8.3 mg/kg/day) | 120-fold |
| 95th percentile of regular users (1.4 cans/day) | 1,400 mg/day (23.3 mg/kg/day) | 43-fold |
| Extreme consumers reported in surveys (8–12 cans/day) | 8,000–12,000 mg/day (133–200 mg/kg/day) | Not assessed as a margin |
The NOAEL (no-observed-adverse-effect level) comes from 13-week rat studies. A newer neurotoxicity study supported a NOAEL of 1,500 mg/kg/day for behavioral effects. EFSA’s main conclusions:
- Exposure to taurine at these levels is “not of safety concern,” given the margins and taurine’s status as a normal body constituent.
- Earlier SCF reviews found no sign of genotoxic, teratogenic or carcinogenic potential.
- A crossover study found no additive diuretic effect of 3 g taurine with 240 mg caffeine. Other taurine-caffeine interactions were not investigated.
- Case reports of harm, including deaths, involved very large amounts of energy drinks, exercise or, more often, alcohol. EFSA judged these more likely due to high caffeine and found no scientific evidence for a causal role of taurine.
EFSA assessed the ingredients, not energy drinks themselves. It explicitly did not evaluate the safety of energy drinks as products. It also noted that consumption data for adolescents and young adults may need to be collected. The caffeine in these drinks is the main safety concern, not the taurine.
Who should be cautious
Data are thin for several groups:
- Pregnancy, breastfeeding and children. We found no controlled safety data for supplement doses in these groups. EFSA noted that a 25 kg child drinking the same amount as an adult has about 2.5 times the exposure per kg.
- Kidney disease. Excess taurine is eliminated by the kidneys (shown in rats), and the human pharmacokinetic data come from healthy men.
- People on blood pressure or diabetes drugs. Taurine’s small effects on blood pressure and glucose point the same way as these drugs. Formal interaction studies are lacking.
Legal status and use in sport
Taurine is sold as a dietary supplement and food ingredient. It is not on the WADA 2026 Prohibited List by name. In Japan it is also an approved medicine for MELAS.
Key takeaways
- The longevity evidence is animal-based. Taurine extended median lifespan by 10–12% in mice and improved health markers in female monkeys over 6 months. No human trial has tested it against aging.
- The premise did not hold in human cohorts. Larger NIH and Canadian studies found blood taurine rises or stays flat with age, and is not linked to muscle, strength or mitochondrial function.
- Small, real effects in short trials. Meta-analyses show a small endurance benefit and reductions of about 3–4 mmHg in blood pressure, plus small drops in glucose and triglycerides. Most trials are small and short.
- Short half-life, wide safety margin. A 4 g dose peaks at 1.5 h and clears with a half-life of about 1 h. Up to 3 g/day is the best-documented safe level in healthy adults.
- EFSA cleared taurine in energy drinks, not the drinks. It found no safety concern for taurine at typical intakes and attributed reported harms mainly to caffeine and alcohol.
Sources
- Singh P, Gollapalli K, Mangiola S, et al. Taurine deficiency as a driver of aging. Science. 2023;380(6649):eabn9257. PubMed; PMC.
- Fernandez ME, Bernier M, Price NL, et al. Is taurine an aging biomarker? Science. 2025;388(6751):eadl2116. PubMed.
- Marcangeli V, Cefis M, Hammad R, et al. Experimental evidence against taurine deficiency as a driver of aging in humans. Aging Cell. 2025;24(10):e70191. PubMed.
- NIH Intramural Research Program. IRP researchers conclude that taurine is unlikely to be a good aging biomarker. June 5, 2025. NIH IRP.
- EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). The use of taurine and D-glucurono-γ-lactone as constituents of the so-called “energy” drinks. EFSA Journal. 2009;935:1–31. EFSA Journal.
- Ghandforoush-Sattari M, Mashayekhi S, Krishna CV, Thompson JP, Routledge PA. Pharmacokinetics of oral taurine in healthy volunteers. J Amino Acids. 2010;2010:346237. PubMed.
- Rana SK, Sanders TA. Taurine concentrations in the diet, plasma, urine and breast milk of vegans compared with omnivores. Br J Nutr. 1986;56(1):17–27. PubMed.
- Ohsawa Y, Hagiwara H, Nishimatsu SI, et al. Taurine supplementation for prevention of stroke-like episodes in MELAS: a multicentre, open-label, 52-week phase III trial. J Neurol Neurosurg Psychiatry. 2019;90(5):529–536. PubMed.
- Sunada Y. [Therapeutics for mitochondrial encephalomyopathy]. Brain Nerve. 2023;75(5):523–525. PubMed.
- Mancuso M, Bellusci M, Carelli V, et al. Diagnostic criteria and management of MELAS and stroke-like episodes: consensus-based statements. Eur J Neurol. 2026;33(4):e70588. PubMed.
- Waldron M, Patterson SD, Tallent J, Jeffries O. The effects of an oral taurine dose and supplementation period on endurance exercise performance in humans: a meta-analysis. Sports Med. 2018;48(5):1247–1253. PubMed.
- Deng H, Song T, Yin M, et al. Does one shot work? The acute impact of a single taurine dose on exercise performance: a meta-analytic review. Scand J Med Sci Sports. 2025;35(9):e70123. PubMed.
- Deng H, Wang L, Liu P, et al. Caffeine and taurine: a systematic review and network meta-analysis of their individual and combined effects on physical capacity, cognitive function, and physiological markers. J Int Soc Sports Nutr. 2025;22(1):2566371. PubMed.
- Sun Q, Wang B, Li Y, et al. Taurine supplementation lowers blood pressure and improves vascular function in prehypertension: randomized, double-blind, placebo-controlled study. Hypertension. 2016;67(3):541–549. PubMed.
- Waldron M, Patterson SD, Tallent J, Jeffries O. The effects of oral taurine on resting blood pressure in humans: a meta-analysis. Curr Hypertens Rep. 2018;20(9):81. PubMed.
- Tzang CC, Chi LY, Lin LH, et al. Taurine reduces the risk for metabolic syndrome: a systematic review and meta-analysis of randomized controlled trials. Nutr Diabetes. 2024;14(1):29. PubMed.
- Nie Z, Liu Y, Zhang M, et al. Effects of oral taurine supplementation on cardiometabolic risk factors: a meta-analysis and systematic review of randomized clinical trials. Nutr Rev. 2026;84(10):2028–2051. PubMed.
- Tao X, Zhang Z, Yang Z, Rao B. The effects of taurine supplementation on diabetes mellitus in humans: a systematic review and meta-analysis. Food Chem (Oxf). 2022;4:100106. PubMed.
- Cao Q, Nie Z, Liu Y, et al. Effects of taurine supplementation on cognitive function: a systematic review and meta-analysis of randomised controlled trials. Int J Food Sci Nutr. 2025;76(4):370–380. PubMed.
- Shao A, Hathcock JN. Risk assessment for the amino acids taurine, L-glutamine and L-arginine. Regul Toxicol Pharmacol. 2008;50(3):376–399. PubMed.
- World Anti-Doping Agency. The 2026 Prohibited List. WADA.