Valerian is a pink or white flowering plant, originally from Europe and some parts of Asia, also called garden valerian and all-heal, which is indicative of its beneficial nature. Its flowers have a sweet scent and extracts were once used as perfume.
As a medicinal herb, valerian has been around for at least 2,000 years: the great Greek physician, Hippocrates (as in the Hippocratic Oath), recognised its properties, and his Roman successor, Galen, prescribed it for insomnia. The extract of its roots is commonly sold as a dietary supplement to promote sleep, in capsules, tablets, or as an infusion.
Valerian root may have sedative and anti-anxiety properties as it contains gamma-aminobutyric acid (GABA), which is the most important inhibitory neurotransmitter in the central nervous system, together with other similar components in its chemical make-up which act on GABA receptors and produce a sedative effect.
Several studies have been undertaken on the efficacy of valerian root as a sleep aid, showing some improvements in quality of sleep and the amount of time needed to fall asleep, but results were inconclusive, particularly as there is little regulation on the composition of the extracts, or which particular combination of chemical elements are present.