Melatonin is a hormone that occurs naturally in the body and also can be taken as a supplement. Melatonin helps maintain the body's circadian rhythm, an internal system that affects when people fall asleep and wake up. The body produces more melatonin during hours of darkness. Melatonin supplementation shows benefits for various sleep disorders and for sleep enhancement, according to the U.S. National Institutes of Health (NIH). Melatonin supplements have some side effects to take into consideration.
Minor Side Effects
Several relatively minor side effects associated with melatonin use occur more often with higher doses. They include dizziness, headaches, abdominal discomfort or cramping and nausea.
Sleep Effects
Some people taking melatonin may experience irregular sleep-wake cycles, according to the NIH. Other sleep-related side effects include sleepwalking, vivid dreams and nightmares. A person may experience drowsiness or fatigue the morning after taking melatonin, especially if he took a high dose.
Psychological Effects
Side effects of melatonin include confusion, disorientation, giddiness, irritability, sadness and mood changes. Studies have indicated that melatonin supplements worsen depression symptoms, according to the University of Maryland Medical Center (UMMC). In one animal study cited by the UMMC, melatonin supplements decreased effects of the antidepressants desipramine (Norpramin) and fluoxetine (Prozac). The NIH notes that hallucinations and paranoia have also been reported and may result because of melatonin overdose.
Cardiovascular and Blood Sugar Effects
Melatonin may lower blood pressure, a consideration for anyone taking blood pressure medication. Increases in cholesterol levels also may occur, according to the NIH. So people with high cholesterol, atherosclerosis, or who present a risk for cardiovascular disease should be cautious about taking melatonin. Some individuals have experienced abnormal heart rhythms while taking melatonin. Melatonin also may affect blood clotting, so people taking anticoagulants or who have clotting disorders may not be able to safely use this supplement. Some type 1 diabetes patients have developed elevated blood sugar levels when taking melatonin.
Sex and Pregnancy Considerations
Melatonin side effects include decreased sperm count and motility, and women attempting to become pregnant should not take melatonin because it may decrease their fertility. Use of this supplement also may result in a decreased sex drive. Breast enlargement in men taking melatonin has been reported, according to the NIH. Other hormonal effects associated with melatonin supplements include decreases or increases in progesterone, estradiol, thyroid hormone, growth hormone, prolactin, cortisol and others. Taking melatonin supplements during pregnancy may raise melatonin levels high enough to increase the risk of developmental disorders. Breastfeeding women also should not take melatonin as it can be transferred to the baby.
Member Comments