Melatonin is a hormone produced by the body’s pineal gland. Melatonin responds to the presence and absence of light, which affects sleep-wake cycles. As a supplement, melatonin is not well absorbed by the body and is rapidly metabolized by the liver. Research supports the efficacy of melatonin for jet lag and sleep-related problems. There is mixed evidence supporting its efficacy in other purported uses, such as for depression, nicotine withdrawal, and, prostate cancer. Clinical trials are underway testing the use of melatonin for a variety of indications.
Attention for Liver Disease: Melatonin has been linked to autoimmune hepatitis. Because it appears to interact with cytochrome p-450 metabolized substances (see Cytochrome P-450), do not take melatonin during HCV treatment.
Safety Information: Melatonin has few side effects when used short-term. Common side effects include fatigue, dizziness, irritability, headache, mood changes, disorientation, eye problems and gastrointestinal complaints. There may be an increased risk of blood clotting, particularly for those taking blood-thinning drugs. Use cautiously if there is a history of seizures, major psychiatric problems, heart disease, blood pressure problems, and diabetes. Hormonal side effects have been reported, so use cautiously with any condition or medication that may be influenced by hormones. Long-term effects are unknown. Pregnant and nursing women should avoid melatonin. Not enough evidence to recommend safe use for children.
Interactions: May interact with any cytochrome p-450 metabolized substances (see Cytochrome P-450). Use cautiously with alcohol, caffeine, blood-thinning, anti-depressant, anti-seizure, blood pressure, diabetic and any sedating medications and supplements. Use cautiously if taking Nifedipine or Fluvoxamine.
Lab Notes: May affect blood pressure, blood sugar levels and blood-clotting tests.
Note: Taking melatonin too early in the daytime may cause daytime drowsiness.