Ask Well: Does Melatonin Aid Sleep?
Question: Is there good evidence on the effectiveness of melatonin for sleep problems?
Answer: Melatonin has been shown to be effective in randomized clinical trials — the kind considered the gold standard in medicine — but it may work better for some sleep problems than others.
“There is pretty strong evidence it’s effective for jet lag,” said D. Craig Hopp, a program director at the National Center for Complementary and Integrative Health, part of the National Institutes of Health. But “the evidence is more equivocal for chronic things like insomnia.”
“相当有力的证据表明褪黑素可有效地帮你调整时差，”美国国立卫生研究院(National Institutes of Health)国家补充与替代医学中心(National Center for Complementary and Integrative Health)的项目主管之一克雷格·霍普(Craig Hopp)说。但是，“对于失眠等慢性疾病，证据就不那么确凿了。”
A 2002 Cochrane review that analyzed 10 randomized trials, most of them comparing oral melatonin to placebo, concluded that melatonin is “remarkably effective in preventing or reducing jet lag.” It not only helped people fall asleep faster and sleep more soundly, but also led to less daytime fatigue and improved general well-being.
Eight of the 10 trials found that taking melatonin for several days after arriving at a destination reduced jet lag from flights crossing at least five time zones. In many of the trials, people also took melatonin on the day of the flight or for several days before the trip, usually in the late afternoon or early evening. Once at the destination, melatonin should be taken close to bedtime, aiming for the local hours between 10 p.m. and midnight. Doses of 0.5 milligrams and 5 milligrams were both effective, though people fell asleep faster and slept better with the larger dose.
For others with insomnia, melatonin has more modest benefits. A 2013 analysis that looked at 19 randomized controlled trials involving 1,683 subjects determined that on average, melatonin reduced the amount of time it took to fall asleep by seven minutes when compared with placebo and increased total sleep time by eight minutes.
Melatonin, a hormone, is sold as a dietary supplement and has not been approved for safety and effectiveness by the Food and Drug Administration. It is generally considered safe for short-term use. Side effects include nausea and drowsiness, but people with epilepsy or those taking warfarin have experienced more serious complications.
褪黑素是一种激素，它通常作为膳食补充剂出售，其安全性和有效性并没有经过美国食品和药品监督管理局(Food and Drug Administration)的审批。一般认为，短期使用它是安全的。可能的副作用包括恶心和嗜睡，但在癫痫患者以及正在服用华法林(warfarin)的患者中曾发生过较为严重的并发症。