Taurine is not a stimulant, but it plays an important role in several physiological functions.

Taurine does not have any stimulating effect. It is a sulphur-containing amino acid, which is not incorporated into proteins but does play a role in many important physiological functions, including retinal and neurological development, osmoregulation, modulation of cellular calcium levels and immune function. It is one of the main ingredients in energy drinks. Taurine is an amino acid which is widely found in animal tissues and also present in the daily diet and in most infant formulae. It is also a natural constituent of the human body. Approximately 0.1% of the total human body weight come from taurine. Taurine in energy drinks is synthetically produced and safe for consumption.

In 2009, in line with numerous health authorities across the world, the European Food Safety Authority (EFSA), which is the risk assessment body for food safety in the European Union, concluded that the exposure of taurine at levels presently used in energy drinks is not of a safety concern. This was confirmed by the EFSA in its scientific opinion on the safety of caffeine (2015).