Taurine or L-taurine is a conditionally essential amino acid that is normally synthesised in the body from cysteine with the help of vitamin B6. Although taurine is referred to as an amino acid it is technically an 'amino sulfonic acid'. It is not used to build protein but has many other important functions in the body. It may be particularly important for vegetarians and vegans because it is only found in animal sources. In fact, during times of extreme stress and illness the body may be unable to produce taurine.
Taurine has a key role in maintaining proper hydration and electrolyte balance in cells, forming bile salts (which play an important role in digestion), insulin sensitivity and protecting mitochondria from reactive oxygen species.
In mitochondria, taurine has been shown to be a key regulator of levels of superoxide production (superoxide promotes hydroxyl-radical formation which damage all cells) and of oxidative phosphorylation since taurine deficiency results in oxidative stress in mitochondria through respiratory chain impairment.
Taurine is often taken before bed due to its central nervous system neuromodulation. It increases glycine and GABA to calm the brain. This effect can may help to reduce anxiety and improve sleep quality, especially when paired with magnesium.