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-HTP (5-Hydroxytryptophan) 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.