5-HTP (5-Hydroxytryptophan) is a naturally occurring amino acid and chemical precursor in the biosynthesis of the neurotransmitter serotonin. It is derived from the amino acid L-tryptophan, and is converted in the body into serotonin, a neurotransmitter that helps regulate mood, appetite, and sleep. 5-HTP is believed to increase serotonin levels in the brain, which may help alleviate symptoms of depression, anxiety, and insomnia. Some studies have also suggested that 5-HTP may have other health benefits, such as reducing symptoms of fibromyalgia, migraine headaches, and obesity.