More than one-third of Americans suffer from sleep deprivation, according to the National Institutes of Health. One in five has tried a natural remedy, generally melatonin, to sleep better, Consumer Reports found, driving sales of the hormone up to $425 million in 2018. About 3 million adults and half a million children take the supplement today.
The pineal gland produces most melatonin naturally, and levels of the hormone rise in the evening as daylight diminishes to prepare the body for sleep. Morning light triggers the body to stop producing melatonin and increase alertness. Supplements with melatonin use a synthetic version of the hormone.
Strong evidence supports the use of melatonin for individuals who need to alter their sleep schedule, whether they have delayed sleep phase, jet lag, or shift work that requires sleep during the day. It also helps reset circadian rhythms in the blind.
Most people use melatonin for insomnia, hoping it will help them go to sleep sooner and stay asleep longer. Studies show that, on average, people with insomnia fall asleep about 7 minutes faster with melatonin than with a placebo. Because of the minimal benefit, the American Academy of Sleep Medicine does not recommend it for this use.
Many people report good results, however. Benefiting most tend to be elderly persons and children, as both groups are more likely to produce insufficient melatonin on their own. For children with autism spectrum disorder, melatonin has been shown to add an extra hour to their nightly sleep.
A low dose works for most people, with 0.2 mg to 0.5 mg often being effective. Johns Hopkins sleep expert Luis F. Buenaver, PhD, recommends 1 mg to 3 mg 2 hours before bedtime. That amount will raise most people’s melatonin levels to 20 times normal.
Melatonin has not been studied for long-term use, so Dr. Buenaver recommends discontinuation in 2 weeks for people who have not seen results and in 2 months for those who find it helpful.
Some patients should be advised that melatonin may affect their prescription drugs or chronic illnesses, according to the Mayo Clinic. Use with anticoagulants and antiplatelet drugs or supplements can increase the risk of bleeding, while use with anticonvulsants can reduce their effectiveness. Melatonin may increase blood pressure in individuals taking medication for hypertension and increase blood glucose levels in diabetics. Melatonin can also increase the sedative effect of central nervous system depressants and diminish the effectiveness of immunosuppressive therapy and medications for epilepsy.
The hormone slows the processing of certain drugs by the liver. Some drugs in this category include acetaminophen, amitriptyline, clopidogrel, clozapine, diazepam, estradiol, olanzapine, ondansetron, propranolol, ropinirole, tacrine, theophylline, verapamil, and warfarin.
Both contraceptives and fluvoxamine increase melatonin levels and its effects, including excessive drowsiness.
Melatonin is not recommended for pregnant or nursing women.
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