The serotonin levels in the body are associated with the regulation of sleep, mood, and appetite. A balanced serotonin level has been shown to support restful sleep, good mood, and decreased sugar cravings. There are several ways to support a healthy serotonin level. L-tryptophan and 5-Hydroxytryptophan (5-HTP) are both precursors to serotonin. However, supplementation with 5-HTP is preferable, because unlike L-tryptophan, 5-HTP cannot be shunted into other uses in the body, such as niacin or protein production. 5-HTP is well absorbed by the body and easily crosses the blood-brain barrier where it can increase the synthesis of serotonin in the central nervous system. And 5-HTP can be taken with meals without reducing its effectiveness.

5-Hydroxytryptophan (5-HTP) is the intermediate metabolite the body produces when it initiates the process of converting the essential amino acid L-tryptophan to serotonin. Therefore, supplementation with 5-HTP will bypass the conversion of L-tryptophan into 5-HTP by the enzyme tryptophan hydroxylase – which is the rate-limiting step in the synthesis of serotonin – and is a conversion that can be inhibited by a number of factors, including stress, insulin resistance, increasing age, and deficiencies of vitamin C, folate, and iron. 5-HTP is well absorbed when taken orally, with about 70 percent going into the bloodstream.* Intestinal absorption of 5-HTP does not require the presence of a transport molecule, and its absorption is not affected by the presence of other amino acids; therefore, 5-HTP can be taken with meals without reducing its effectiveness. 5-HTP has been shown to have a beneficial impact on mood, sleep, carbohydrate cravings, and discomfort associated with fatigue. Numerous studies of individuals with negative mood status have shown significant positive response with 50-300 mg of 5-HTP daily.

To further facilitate serotonin production, Thorne's 5-HTP formula contains pyridoxal 5'-phosphate, the active form of vitamin B6 and the necessary cofactor for the conversion of 5-HTP to serotonin. 5-HTP is commercially produced by extraction from the seeds of the African plant, Griffonia simplicifolia.