5-Hydroxytryptophan is an intermediate metabolite in the pathway from tryptophan to serotonin. 5-hydroxytryptophan supplementation enhances serotonin levels. Serotonin is involved in the body's control of sleep, mood regulation, & appetite. A woman who is pregnant, or who might become pregnant, should not use 5-hydroxytryptophan. 5-hydroxytryptophan is specifically contraindicated during pregnancy.1 to 2 capsules