What happens if I take melatonin after drinking?

If your goal is to wake up feeling refreshed each day, you won't be doing yourself any favours by mixing melatonin and alcohol before bed. Photo / 123RF

Q: I take melatonin to help me sleep at night. But I also like to enjoy a glass of wine or two after a long day to unwind. Is it safe to do both?

A: The struggle to get a decent night’s sleep is real. In 2020, about 15 per cent of adults in the United States had trouble falling asleep regularly, according to the Centers for Disease Control and Prevention, and nearly 18 per cent had difficulty staying asleep. And increasingly, many people are taking melatonin in their quest for better shut-eye. Use of the supplement, which is sold over the counter as a sleep aid, has risen significantly over the past two decades.

But if your goal is to wake up feeling refreshed each day, you won’t be doing yourself any favours by mixing melatonin and alcohol before bed — and you may even be putting your health at risk, said Dr Rachel Salas, a professor of neurology at Johns Hopkins Medicine and the assistant medical director at the Johns Hopkins Center for Sleep and Wellness.

How does melatonin affect sleep?

Melatonin is not just a supplement that you can buy at the store. It’s also a hormone that your brain produces naturally in response to darkness, and its purpose is to signal that it’s time for sleep, said Dr Rafael Pelayo, a clinical professor in the sleep medicine division at Stanford Medicine and the author of How to Sleep. Contrary to popular belief, however, melatonin supplements don’t necessarily make you conk out quickly the way many classic sleeping pills do, Pelayo said. Melatonin is not a cure-all for insomnia. Instead, it is most useful in shifting the timing of your sleep by adjusting your circadian rhythm, also known as the 24-hour internal clock that regulates your sleep-wake cycle.

“If someone’s sleep problems are related to their circadian rhythm — the classic example of this would be jet lag — melatonin might help,” said Philip Gehrman, an associate professor of clinical psychology at the Perelman School of Medicine at the University of Pennsylvania. For instance, though people typically adjust to a new destination’s time zone by about an hour per day, “taking melatonin can speed up that adjustment further,” he said. One caveat: Melatonin only works well in this way if you take it at the same time each evening (usually about half an hour or an hour before bed) and if you’re consistent about when you go to sleep at night and when you wake up in the morning. It’s also important to talk with your doctor before taking melatonin, Gehrman said, to make sure it’s appropriate for you and, if so, what dosage you should take.

What effect does alcohol have on sleep?

Alcohol, on the other hand, is not an effective sleeping tool. While that glass (or two) of wine may lead you to nod off swiftly, it can backfire by causing you to wake up more frequently throughout the night, making your overall sleep quality worse, Salas said.

What’s more, alcohol depresses the central nervous system, causing decreased heart rate and slowed brain activity and breathing. So for those who have sleep apnea, a condition that causes breathing to stop repeatedly throughout the night, alcohol can exacerbate symptoms, which can limit oxygen intake further and, in some cases, may even be life-threatening, Salas said.

So at what point in the evening should you cut yourself off? “It’s not a precise science because we all metabolise alcohol at different rates, and obviously it depends on how much you’re having,” Gehrman said. As a general rule of thumb, he suggested avoiding drinking alcohol about two to three hours before bedtime.

What happens when you take melatonin and alcohol together?

There isn’t much research into the effects of taking the two at the same time, but experts say it’s best not to do it.

For one thing, doctors discourage people from consuming alcohol, which can initially be sedating, with medications or supplements that could also be sedating. And while melatonin is not likely to knock you out, it could still “have a bit of a sedating effect” in some people, Gehrman said. So “the more conservative approach,” he said, would be to steer clear of mixing melatonin with alcohol so as not to risk becoming overly sedated.

Drinking close to bedtime is also likely to derail melatonin’s role in keeping your internal clock on track. Not only will the alcohol disrupt your sleep, but it may also make it difficult for you to stick to your sleep routine if it causes you to go to bed later, sleep in, nap during the day or fall sleep earlier than normal, for example, Salas said. She emphasized that the timing of your melatonin intake is critical to getting a good night’s rest. “You don’t want to take melatonin at random times,” Salas said. “Either take it consistently, or don’t take it at all.” So if you plan on taking melatonin, aim to stop drinking at least two to three hours beforehand, and if you do end up having a drink late in the evening, it’s better to skip the melatonin until the following night.

If you decide to take melatonin (preferably without alcohol), ask your doctor what brands they recommend, as supplements are not regulated by the Food and Drug Administration and research shows that melatonin supplements don’t always contain what their labels claim they do. Or if you’re at the store, look for products with a verified mark from the US Pharmacopeia or NSF International, both of which are independent nonprofits that test supplements for quality and safety.

Of course, if you’re having trouble sleeping and melatonin isn’t doing the trick, seek out a sleep specialist. “People who have insomnia are at increased risk for cardiovascular disease, a higher incidence of mood disorders and worse quality of life,” Salas said. “So if you’re struggling, you really should talk to your doctor because we know that sleep is so important for health and wellness.”

And skip the nightcap before bed.

This article originally appeared in The New York Times.

Written by: Rachel Rabkin Peachman

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