Taurine: side effects and safety evidence

Taurine is associated with energy drinks, and therefore with their risks - palpitations, insomnia, pressure spikes. But is taurine to blame? The editors analyzed what side effects are really characteristic of this substance, how frequent they are, and who should be careful.

How safe is taurine in general

Among popular sports supplements, taurine has one of the best safety profiles. It is naturally present in the body in large quantities, and its excess is effectively removed by the kidneys. The toxicity of taurine in usual doses in humans has not been described.

The most famous risk assessment is the work of Shao and Hathcock (2008), who applied the method of "observed safe level" (Observed Safe Level, OSL). They concluded that taurine has strong safety data at up to 3 g per day from supplements, and higher doses have also been well tolerated in studies, but there is less data on long-term use.

The European Food Safety Agency (EFSA) evaluated taurine in energy drinks in 2009 and concluded that regular consumption of taurine in amounts typical of such drinks does not raise safety concerns. The calculations included consumption scenarios at the level of up to 3 g of taurine per day.

So, at moderate doses, taurine side effects are rare and usually mild. However, "rare" does not mean "absent", and some groups of people have reason to be cautious.

Gastrointestinal reactions and general complaints

The most frequent complaints when taking taurine, as with most supplements in the form of powder or capsules, concern digestion. Some people report a feeling of heaviness in the stomach, mild nausea or irregular bowel movements, especially when taking a large single dose on an empty stomach.

Such reactions usually disappear after reducing the dose or taking taurine with food. Dividing the daily amount into two or three meals also helps to reduce the burden on the digestive system.

Sometimes users note drowsiness or, on the contrary, slight excitement. Drowsiness can be explained by the neuromodulatory effect of taurine on GABA and glycine receptors. Excitement is more often associated not with taurine, but with caffeine, which is contained in energy drinks and pre-workout complexes.

Headache and dizziness in controlled studies of pure taurine are not typical. If these symptoms occur after energy, the most likely cause is caffeine, sugar or dehydration, not taurine.

• Stomach discomfort, nausea — with large single doses.
• Stool disorder — rare, usually dose-dependent.
• Drowsiness is possible due to the neuromodulatory effect.
• Excitement, tachycardia — more often due to caffeine in combined products.

Heart, blood pressure and energy drinks

Taurine is often associated with heart problems through energy drinks. Medical literature describes cases of arrhythmias and other cardiovascular complications after excessive consumption of energy drinks. However, these drinks contain significant amounts of caffeine and sugar, and it is caffeine that has a well-known effect on heart rate and blood pressure.

Regarding taurine itself, the data are rather opposite. In a randomized, placebo-controlled trial by Sun et al (2016), taurine in people with prehypertension lowered blood pressure and improved vascular function. Therefore, taurine does not raise blood pressure, but can moderately lower it.

This property also has a reverse side. People who already take antihypertensive drugs or those who are prone to low blood pressure should consider the possible additive effect. It is probably small, but in combination with medication it can manifest itself as dizziness.

The editors emphasize: if a person experiences palpitations, chest pain, or interruptions in the work of the heart after energy, this is a reason to consult a doctor, and not to look for the "culprit" among individual ingredients.

Groups of increased caution

The first group is people with chronic kidney disease. Since the kidneys are the main organ of taurine excretion, when their function is reduced, accumulation of the substance is possible. The clinical significance of this is not fully understood, but the use of supplements in such patients should be coordinated with a nephrologist.

The second group is pregnant and breastfeeding women. Taurine is naturally present in breast milk and is important for a baby's development, but the safety of high-dose supplements during this period has not been studied. Therefore, independent intake of taurine in excess of dietary intake is not recommended.

The third is people taking medications that affect blood pressure or the central nervous system. Theoretically, it is possible to increase the antihypertensive or sedative effect. The possible influence of taurine on lithium excretion is also discussed in the literature, but there is little reliable clinical data; people on lithium therapy should discuss any supplements with a psychiatrist.

The fourth is children and teenagers. Taurine in infant formulas is safe and necessary, but energy drinks with taurine and caffeine are not recommended for children and adolescents because of the caffeine, and taurine supplements in sports doses have not been studied for them.

How to reduce the risk of unwanted reactions

The simplest rule is to stick to doses for which safety data exist. For most adults, this is up to 3 g of taurine per day from supplements. Higher amounts have been used in some studies, but there is no point in going beyond this limit without a real need.

The second rule is to choose pure taurine, not combined products, if the goal is to evaluate its effect. This makes it easier to understand which substance caused this or that reaction, and to control caffeine consumption separately.

The third is to monitor the total income. Energy drinks, pre-workout complexes, some "fat burners" and isotonics contain taurine. A person who takes several such products can imperceptibly receive much more than he planned.

Finally, it is worth choosing products from proven manufacturers with independent certification: side effects in sports nutrition are often associated not with the declared substance, but with low-quality raw materials or undeclared impurities.

Editorial conclusions

Taurine is one of the safest sports supplements: risk assessments support the safety of up to 3 g per day, and no serious side effects of pure taurine have been reported in studies.

The most frequent adverse reactions are mild gastrointestinal symptoms at high doses. Heart complaints after energy drinks are most often associated with caffeine, and taurine itself can even moderately lower blood pressure.

People with kidney disease, pregnant women, children, as well as those who take antihypertensive, sedative or lithium preparations need to be careful.

We also advise you to read our materials "Taurine: what it is and how it works", "How to take Taurine: dosage, time of administration, duration" and "Who should not take Taurine".

List of used literature

1. Shao A, Hathcock JN. Risk assessment for the amino acids taurine, L-glutamine and L-arginine. Regul Toxicol Pharmacol. 2008;50(3):376–399.
2. 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 J. 2009;7(2):935.
3. 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.
4. Huxtable RJ. Physiological actions of taurine. Physiol Rev. 1992;72(1):101–163.
5. Schaffer SW, Kim HW. Effects and mechanisms of taurine as a therapeutic agent. Biomol Ther (Seoul). 2018;26(3):225–241.
6. Kurtz JA, VanDusseldorp TA, Doyle JA, Otis JS. Taurine in sports and exercise. J Int Soc Sports Nutr. 2021;18(1):39.