Is the taurine in energy drinks harmful?

Taurine in energy drinks, at the amounts found in common products, has not been shown to be harmful. Multiple studies found no reports of negative health effects at those levels. Those amounts are far below what would be needed for therapeutic or toxic effects.

The safety profile of taurine is less well studied than that of caffeine. There are no clear indications of harm, but its safety has not been fully established either. In a laboratory study, cell damage occurred in human nerve cells when taurine, caffeine and guarana were combined. However, those concentrations were much higher than what you would take in from a can, so this result says little about normal use.

There is even preliminary evidence that taurine counteracts some of the unwanted cardiac effects of caffeine. A European scientific committee concluded as early as 2003 that this may be the case, but it has not yet been sufficiently studied in humans to make firm statements about this.

The real risks of energy drinks lie in the caffeine, not in the taurine. Documented side effects of caffeine include insomnia, nervousness, headaches and heart palpitations. Four documented deaths and four cases of seizures have been associated with energy drink consumption. If you are concerned about energy drinks, caffeine is the substance to watch, especially if you drink a lot or are sensitive to caffeine.