5-Hydroxytryptophan (5-HTP, CAS: 4350-09-8) is a naturally occurring amino acid that serves as a metabolic intermediate in tryptophan and a precursor to the neurotransmitters serotonin (5-hydroxytryptamine, 5-HT) and melatonin.
As a precursor of serotonin and melatonin, 5-HTP regulates brain neurotransmitter levels, thereby influencing mood, sleep, and appetite. Research suggests that 5-HTP may help alleviate mild depression, anxiety, and insomnia, and may aid weight loss by increasing satiety. It has also been used to improve symptoms of fibromyalgia and migraines.