June 30, 2021

What to Know About Over-the-Counter Sleep Aids

The scoop on sleep supplements and sleeping pills

man trying to sleep in bed

It’s late. It’s dark. You’re tired. (So tired.) So why – why – are you still staring at the ceiling, wide awake?


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If you’re experiencing insomnia, a pill to make you sink into dreamland sounds like magic. Drugstore shelves are lined with medications and supplements that promise a good night’s sleep. But do they work? And are they safe?

Family medicine doctor Matthew Goldman, MD, gives us the lowdown on common over-the-counter sleep aids.

Diphenhydramine and doxylamine (antihistamines)

What they are

Both diphenhydramine and doxylamine are antihistamines, medications that are often used to fight allergies. But diphenhydramine and doxylamine are part of a family of antihistamines that can act on your central nervous system and have a sedating effect. In other words, they can make you sleepy.

You can find diphenhydramine and doxylamine in many over-the-counter sleep aids. Diphenhydramine is the snooze-inducing ingredient in drugs like:

  • Benadryl®.
  • Unisom®.
  • Advil PM®.

Doxylamine is found in products such as:

  • Unisom® SleepTabs.
  • Tylenol® Cold and Cough Nighttime.
  • Vicks NyQuil® Cough.

Side effects

These drugs affect people differently. Some have few side effects while others aren’t so lucky. “Older patients are often more sensitive to side effects, so they should limit or avoid using these products,” Dr. Goldman says. Possible side effects include:

  • Agitation or nervousness.
  • Dizziness.
  • Nausea.
  • Constipation.
  • Dry mouth.
  • Headache.

Call your doctor immediately if you have these serious side effects:

  • Vision problems.
  • Urination problems.

How to use it

Follow the dosage instructions on the package and don’t mix the drugs with alcohol or other sedatives. Also, don’t take these drugs night after night. “These medications aren’t recommended for chronic insomnia, but they can help if you’re occasionally having trouble falling asleep,” Dr. Goldman says.


What it is

Melatonin is a hormone your brain makes. “Melatonin regulates your sleep-wake cycle,” Dr. Goldman explains. “The amount made by your body normally peaks at night, which causes you to feel sleepy.” If you’re having trouble sleeping, melatonin supplements might send you off to dreamland.

Side effects

Melatonin isn’t linked to major side effects, Dr. Goldman says. But there’s some evidence it may cause:

  • Dizziness.
  • Nausea.
  • Headaches.
  • Confusion.
  • Fragmented sleep.

How to use it

In the United States, you can buy melatonin as a dietary supplement. The typical dose can range from 1 milligram to 10 milligrams. If you’re trying it for the first time, Dr. Goldman recommends starting with 1 milligram or even splitting a pill in half and taking just 0.5 milligrams.

Once you see how it affects you, you might gradually increase your dose. “Talk to your healthcare provider to determine the right dose for you,” he says. “But in general, starting low and going slow is the best way to go for all medications and supplements.”

Melatonin is best for short-term treatment of insomnia. It’s also helpful for reducing jet lag when traveling and can help people who do shift work fall asleep at irregular hours. “It’s a safe choice, but don’t use it for more than three months at a time,” Dr. Goldman says.

Valerian root

What it is

Valerian is an herbal supplement made from dried roots. It contains compounds that may act on receptors in the brain, potentially slowing down the nervous system and making you drowsy. “But it’s not completely known yet how valerian root works,” Dr. Goldman says. And it’s not a sure thing. Research studies testing how effective valerian is for insomnia have had mixed results.


Side effects

There are few reports of serious side effects from valerian, aside from feeling drowsy (a good thing if you’re taking it for insomnia). But some people may experience dizziness, Dr. Goldman says.

How to use it

Valerian is sold as a dietary supplement in tablet and capsule form. Follow the dosage instructions on the bottle. And like melatonin, it’s a good idea to start with a low dose. Since it’s a sedative, valerian could, in theory, slow down your breathing, Dr. Goldman adds — especially if you combine it with other medications. “Talk to your healthcare provider first, and avoid taking it with alcohol or other sedatives,” he says.

Sleep strategies that work (sleep aids not required)

If you have an occasional sleepless night, over-the-counter sleep aids can be a helpful short-term fix. But if insomnia is a regular thing, there are better strategies.

Dr. Goldman offers these tips to set yourself up for slumber success:

  • Practice good sleep hygiene: “Maintain a regular bedtime and wake time routine. Get out of bed if you aren’t sleepy. And avoid alcohol, tobacco, stimulants and electronic devices before bed,” he says.
  • Get regular exercise: A better night’s sleep is yet another benefit of exercise.
  • Find the light: Get outside for a dose of sunlight, especially in the morning.
  • See a counselor: Therapists can teach cognitive behavioral therapy for insomnia (CBT-I), a drug-free treatment to improve sleep.
  • Keep a diary: Dr. Goldman recommends keeping a sleep journal so you and your doctor can look for patterns to better understand when you sleep — and when you struggle. Armed with information, you can find the right path forward for a good night’s rest. “It’s always a good idea to talk to your doctor or a sleep specialist before trying new sleep aids or supplements,” Dr. Goldman says.

It might take some effort to turn your insomnia around. But it’ll be worth it when you wake up bright-eyed and bushy-tailed after a deep, restful slumber.

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