5-HTP (5-hydroxytryptophan) is an amino acid precursor to the brain chemical serotonin, a neurotransmitter that is essential for balancing mood, along with performing cognitive tasks such as learning and memory formation. Lowered mood as well as other conditions have long been associated with low serotonin levels, making 5-HTP an attractive natural option to elevate mood and improve emotional health. Timed-release caplets bypass the limitations of immediate-release formulations. This allows for a sustained increase in serotonin, avoiding spikes, fluctuations, and the rapid drops associated with missed or delayed dosing. Additionally, timed-release formulations may help minimize the gastric discomfort some individuals experience with 5-HTP.

Clinical research supports 5-HTP supplementation for mood. A randomized double-blind clinical trial of 60 patients assessed the efficacy of 5-HTP supplementation as compared to fluoxetine. Efficacy was determined by comparing initial HAM-D scores obtained at baseline to those at 2 weeks, 4 weeks, and 8 weeks. Following 5-HTP supplementation, 73% of patients taking 5-HTP and 80% of patients taking fluoxetine showed significant reduction in HAM-D scores starting at week two and through to the end of the study.

5-HTP has also been used to address serotonin imbalance implicated in chronic pain conditions including migraines as well in fibromyalgia and insomnia. People with fibromyalgia who take 300–400 mg of 5-HTP daily in divided doses have reported improvements in symptoms, including pain severity, morning stiffness, and sleeplessness. 5-HTP is known to increase sleep quality, which is critical in those suffering from fibromyalgia. In fact, 5-HTP has been shown to promote REM sleep in healthy adults. The increased time spent in REM sleep is one of the reasons why 5-HTP is considered a sleep aid.