l-Tryptophan | Melatonin | Valerian Extract
A hypnotic drug that seems to be free of dependence or abuse
liability is the amino acid l-tryptophan.
It has not been formally approved for medical use as a hypnotic
drug in the United States, but it was available in both drugstores
and health food stores as a dietary supplement, either in the pure
form or combined with other nutriments. There was reasonable evidence
that, at doses of 1–6 g at bedtime, l-tryptophan
had some efficacy as a sleeping pill in some patients with insomnia.
It was neither as powerful as the major hypnotics nor, presumably,
as dangerous. It would be, however, a rather expensive way to get
a night's sleep, because the drug used to cost (in the
1980s) almost $1 per gram.