Taurine

What taurine is and how it is supposed to work

Chemically, taurine is not a classical amino acid but an aminosulfonic acid, and it is not built into proteins. It is present freely in the cell: the heart, retina, skeletal muscle and brain have the largest stores. Your body makes it itself from cysteine and methionine and takes it in through animal foods; taurine does not occur in plants. As an osmolyte it keeps cell volume stable, intervenes in calcium balance and conjugates bile acids. It is also chemically attached to mitochondrial tRNA, from which the story of mitochondrial protection is derived.

The transporter TauT, encoded by the gene SLC6A6, is one of the few points at which the chain of action is anchored in humans. People with two defective copies of this gene develop an early-onset retinal dystrophy; in 7 affected individuals from 4 families, plasma taurine was 31.7 µmol/l lower than in heterozygous relatives. A true taurine deficiency therefore makes people ill. That is a different question from whether an extra amount does anything in healthy people.

The 2023 Science paper and what came after

The paper consists of three parts that can be cleanly separated. The mouse part is the strongest: middle-aged mice received 1,000 mg of taurine per kilogram of body weight per day orally, their median lifespan rose by around 10 to 12 percent, and in 28-month-old animals the expected remaining lifespan was extended by around 18 to 25 percent. Roundworms also lived longer.

The monkey part is interventional but does not measure lifespan. Middle-aged rhesus monkeys received 250 mg per kilogram of body weight per day for 6 months; health markers were measured, and they moved in the hoped-for direction: less body weight and visceral fat, better insulin sensitivity, lower CRP, more grip strength, fewer senescent T cells. The human part contains no supplementation at all; it is observational data. The authors themselves called for clinical studies in the abstract.

Exactly that happened in 2025 for the basic assumption. A paper from the circle of the National Institute on Aging measured circulating taurine in three human cohorts, in rhesus monkeys aged 3 to 32 years and in mice aged 9 to 27 months: the levels rose with age or stayed the same. In the same year, a Canadian group found no association between serum taurine and age, muscle mass, strength or mitochondrial function in 137 men aged between 20 and 93. Decisive for assessing the 2023 paper is their observation: the human correlation back then was carried predominantly by people aged 20 and under, and participants over 65 were missing.

Blood pressure, the field with the best human data

This is where it gets concrete. A meta-analysis pooled 7 studies with 103 participants, doses between 1 and 6 g per day, duration between 1 day and 12 weeks. Systolic blood pressure fell with g = -0.70 (95 % CI -0.98 to -0.41), diastolic with g = -0.62, in absolute terms an average of around 3 mmHg in both values.

The cleanest single study is randomized, double-blind and placebo-controlled: 120 people with prehypertension, 1.6 g per day over 12 weeks. Office systolic blood pressure fell by 7.2 mmHg versus 2.6 mmHg under placebo; in 24-hour measurement, 3.8 versus 0.3 mmHg remained. A meta-analysis of 34 randomized studies arrives at the same results: systolic -4.38 mmHg, HbA1c -0.21 percent, triglycerides -14.42 mg/dl, most clearly at 1.5 to 3.0 g per day and from 8 weeks. These are surrogate markers, and all of them are.

Heart and exercise

The heart has one of the largest taurine stores, and the idea that taurine helps the weakened heart is old. Controlled human data exist, but only small ones. In the largest, 29 patients with an ejection fraction below 50 percent received 500 mg three times daily or placebo for 2 weeks; exercise duration and walking distance rose significantly, but the study was only single-blind. In a double-blind study of 17 patients, taurine at 3 g per day over 6 weeks improved systolic left ventricular function. A third, much-cited study in 16 patients was retracted in 2026.

In exercise, the effect is small. A meta-analysis of 23 randomized studies with 308 participants on the acute single dose arrives at g = 0.25 (95 % CI 0.10 to 0.39), GRADE quality of evidence low to very low. One detail shows the limits of transferability: rodent muscle takes up around 40 percent more taurine after 2 weeks, human muscle nothing measurable after 7 days at 4.98 g per day.

What the studies show

Science 2023, taurine deficiency as a driver of aging

Middle-aged mice on 1,000 mg per kilogram of body weight per day lived around 10 to 12 percent longer in the median, and in 28-month-old animals the expected remaining lifespan rose by around 18 to 25 percent. Rhesus monkeys received 250 mg per kilogram of body weight per day for 6 months and showed better health markers, but no measured lifespan. The human part was pure observation without supplementation.

Science 2025, is taurine a biomarker of aging

Test of the basic assumption in three human cohorts with age ranges of 26 to 100, 20 to 85 and 20 to 68 years, plus rhesus monkeys aged 3 to 32 years and mice aged 9 to 27 months, longitudinally and cross-sectionally. Result: taurine rose with age or stayed the same. The result went against the biomarker thesis.

Hypertension 2016, taurine in prehypertension

Randomized, double-blind, placebo-controlled, 120 participants, 1.6 g per day or placebo over 12 weeks, primary endpoint blood pressure. It was reached: systolic 7.2 versus 2.6 mmHg and diastolic 4.7 versus 1.3 mmHg in office measurement, systolic 3.8 versus 0.3 mmHg over 24 hours. Vasodilation also improved.

Where the data stop

The lifespan figure comes exclusively from mice and roundworms. In the monkeys, no lifespan was measured over 6 months, and in humans there are no data on it, neither positive nor negative. The premise that taurine falls with age was tested twice in 2025 and not confirmed.

All positive human endpoints are surrogate markers: blood pressure, HbA1c, blood lipids, inflammatory values. No study has measured heart attack, stroke or mortality, and the longest interventions run for weeks to months. In heart failure, the basis became thinner in 2026 with the retraction of a much-cited paper. And whether people eating an exclusively plant-based diet benefit has never been tested in a controlled way.

Status, approval and legal

In Germany, taurine is not a medicine but a food ingredient and food supplement. A legal upper limit applies to energy drinks: Annex 8 of the German Fruit Juice and Soft Drinks Ordinance allows at most 4,000 mg of taurine per liter in the ready-to-drink beverage, alongside 200 mg of inositol, 2,400 mg of glucuronolactone and 320 mg of caffeine per liter. For food supplements there is no binding maximum amount. No health claims are authorized in the EU register, and taurine is not on the World Anti-Doping Agency's prohibited list. A phase II study is currently testing 3 g per day over 6 months in 80 planned participants against placebo.

Safety

Taurine is among the better-studied substances on the shelf. The EFSA assessment is based on a NOAEL of 1,000 mg per kilogram of body weight per day from animal studies, 120 times above the average intake from energy drinks. In human studies with 1,000 to 1,500 mg per day, no adverse effects were reported, and the meta-analyses report none either; at 4,980 mg per day over 7 days, one participant reported mild muscle cramps. The Norwegian authority VKM derives a threshold of 21 mg per kilogram of body weight per day from human data, around 1,470 mg per day for an adult weighing 70 kg. This is below the upper end of common product recommendations. In SSADH deficiency, 16 g per day led to hypersomnia with hospital admission. Because taurine lowers blood pressure, combining it with blood pressure-lowering medication should be clarified with a physician. A mouse model of hepatocellular carcinoma also showed accelerated tumor development under taurine.

Sources

• Singh et al., Science 2023 (taurine deficiency as a driver of aging)
• Fernandez et al., Science 2025 (Is taurine a biomarker of aging)
• Marcangeli et al., Aging Cell 2025
• Waldron et al., Current Hypertension Reports 2018 (meta-analysis, blood pressure)
• Sun et al., Hypertension 2016 (RCT, prehypertension)
• Nutrition Reviews 2026 (meta-analysis, 34 RCTs, cardiometabolic)
• Beyranvand et al., Journal of Cardiology 2011 (heart failure)
• Statement of Retraction, Journal of Dietary Supplements 2026
• VKM, Risk assessment of other substances - Taurine, 2015
• German Fruit Juice and Soft Drinks Ordinance (Fruchtsaft- und Erfrischungsgetränkeverordnung), Annex 8