Key takeaways

OTC sleep aids, including antihistamines and herbal supplements, are widely used for occasional sleeplessness but are not recommended for nightly use due to potential side effects and interactions with other medications.
Long-term use of OTC sleep aids can lead to tolerance and decreased effectiveness, making them unsuitable for managing chronic insomnia or sleep disorders.
Older adults, pregnant or breastfeeding women, those with specific medical conditions, or individuals taking other medications should exercise caution or avoid OTC sleep aids altogether.
While prescription sleep aids may be necessary for some persistent sleep difficulties, they come with risks. They should be considered only after consulting with a healthcare provider and exploring non-pharmacological sleep improvement strategies.

Having trouble falling and staying asleep? You’re not alone. As many as 70 million Americans have sleep disorders that can keep them tossing and turning at night, according to the National Library of Medicine. And many of these sleep-seekers reach for over-the-counter (OTC) sleep aids like antihistamines and herbal supplements to help them get the shut-eye they need.

Over-the-counter sleep aids are a booming business, raking in $437 million in 2021 in the United States. Estimates vary on how many people take these medications and supplements, but use does seem to rise with age. A 2017 study revealed that 10% of adults aged 18-45 use OTC sleep aids while 17.5% of people 65 years and older do.

Most over-the-counter options are considered safe when used occasionally—as long as the medication is compatible with any medical conditions you have and other medications you take. But when taken night after night, trouble can mount. Many of these products produce side effects, can interact with other medications you take, and may even stop working if you take them long-term.

So, what’s worth taking? And how often can you safely use it? We’ve talked to the experts about it, so you don’t have to lose sleep over it.

What are over-the-counter sleep aids?

The best OTC sleep aid will vary from person to person. Over-the-counter sleep aids generally fall into two categories: non-prescription sleep medications and natural, dietary supplements.

Non-prescription sleep medications

The active ingredient in many nonprescription medications used as sleep aids is an antihistamine, particularly diphenhydramine or doxylamine succinate. Histamine is a chemical the body produces that helps you feel awake (it also causes allergy symptoms). Antihistamines, which are often used in allergy medications, help block that chemical, so you feel drowsy.

Diphenhydramine is an OTC drug that can be used in individuals 6 years and older for allergic reactions and itching. It can also be used in children ages 2 years to 6 years old, if recommended by the healthcare provider. However, for short-term treatment of insomnia, diphenhydramine should only be used in adolescents and adults 12 years and older. The drug has sedating effects and can cause urinary retention, constipation, dry mouth, and daytime drowsiness. Some of the diphenhydramine-containing products used as sleep aids include:

Benadryl
ZzzQuil
Nytol
Unisom SleepGels
Advil PM (which also contains the anti-inflammatory ibuprofen)
Tylenol PM (which also contains the pain reliever acetaminophen)
Excedrin PM Headache (which also contains acetaminophen and aspirin)

Doxylamine succinate works similarly to diphenhydramine, but it should not be used in individuals younger than 12. Sleep aids containing the drug include:

Unisom SleepTabs
Tylenol Cold/Flu/Cough Nighttime (which also contains the decongestant phenylephrine, the cough suppressant dextromethorphan, and the pain reliever acetaminophen)

People often wonder if there’s an OTC alternative to prescription drugs such as Ambien (zolpidem tartrate), but there is not. Ambien (and similar drugs like Lunesta) is a sedative-hypnotic that works by slowing down brain activity—it is a controlled substance and requires a prescription.

Natural sleep aids

There are a variety of herbal and dietary supplements that people take for sleep, including melatonin, valerian root, chamomile, and CBD.

Melatonin

Your body has a natural circadian rhythm that helps regulate your sleep-wake cycle. In response to light, your body becomes more alert. And as daylight wanes and night creeps in, your body produces melatonin, a hormone made by the pineal gland that helps promote sleep.

Research published in the journal Plos One found that melatonin helped study subjects fall asleep seven minutes sooner than those not taking the supplement and sleep eight minutes longer while also improving their sleep quality.

But melatonin—which seems to work best in those who have disruptions to their circadian rhythms, for example those who are shift workers or who are experiencing jet lag—is not a magic bullet. Its effects are modest, and experts caution that taking more is not necessarily better. For most adults, a starting dosage is 1 mg to 2 mg, with a maximum daily dosage of 5 mg (or up to 10 mg under a healthcare provider’s supervision).

RELATED: A melatonin dosage guide

Short-term use of melatonin to combat sleeplessness is considered safe for most people, but there are some who should proceed with caution. According to Craig Kimble, Pharm.D., an associate professor at the Marshall University School of Pharmacy, this includes:

Adolescents
Women who are pregnant or lactating
People with migraines
People with psychological conditions
People in cancer treatment

Melatonin can cause side effects like headache, nausea, dizziness, and drowsiness, and it interacts with certain medications—which is why it’s important to check with your healthcare provider before using melatonin or any OTC sleep aids.

Valerian root

Valerian root is an herb that’s thought to promote sleep by interfering with the breakdown of the neurotransmitter gamma-aminobutyric acid (GABA), a brain chemical that helps you feel calm and relaxed.

Most studies looking at valerian root and sleep are inconclusive. While some have shown that users fall asleep more quickly (one study showed they fell asleep about seven minutes faster than nonusers, though researchers didn’t believe that this finding was clinically significant) and felt they had improved sleep, others have found no effect. What’s more, many of the studies include small sample sizes and use different sources and amounts of valerian, so it’s hard to draw definitive conclusions.

Valerian root should not be taken with other medications or alcohol and has the potential to slow breathing.

Chamomile

Chamomile is an herb that may play a role in sleep due to its chemical compounds that bind to benzodiazepine and GABA receptors. But studies examining the sleep-inducing effects of chamomile—in tea or extract form—have been mixed. In one small study involving older adult subjects, those receiving capsules containing chamomile extract twice a day for 28 days reported better sleep quality than those in the control group. Yet other studies show that chamomile does not significantly improve things like sleep quality and the total time spent asleep.

CBD

Cannabidiol (CBD) is a compound found in the hemp plant. Studies suggest that oral CBD may be beneficial for promoting sleep and reducing anxiety. Although more research is needed, preliminary data indicates that the compound may be helpful for insomnia and REM sleep disorder. But according to the U.S. Food and Drug Administration (FDA), CBD comes with risks, including liver injury, and animal studies have reported male reproductive toxicity (damage to fertility in males, or in male offspring of females who have been exposed to CBD). CBD can also interact with alcohol and drugs that slow brain activity, and cause side effects when combined with other medications. Be sure to reach out to your healthcare provider for medical advice before using CBD for sleep.

What is the best OTC sleep aid?

For most people, virtually any of the OTC sleep aids are safe to use short term. Some people find them effective, others not as much. But long-term use is not a good idea.

“If you feel as though one of these products benefits you and you’re not encountering significant side effects, then I don’t see a concern [for occasional use],” says Philip Alapat, MD, an assistant professor of medicine-pulmonary at Baylor College of Medicine in Houston. “But these products should not be used on a regular basis.”

If you want to use one, talk to your healthcare provider and pharmacist first. This is especially true if you’re pregnant, breastfeeding, take other prescription or OTC medications, have certain medical conditions like asthma, sleep apnea, or chronic obstructive pulmonary disease, or if you are 65 or older.

Other precautions to take:

Read the dosing directions and don’t exceed what’s recommended.

Avoid alcohol, which in and of itself can cause drowsiness.
Don’t drive or do anything that requires focus and concentration for at least 8 to 10 hours after taking sleep aids.

Is it safe to take an antihistamine for sleep every night?

While antihistamines have been around for decades, there isn’t a lot of good data supporting their use in treating sleep problems. Research has found that they are only minimally effective in getting people to sleep, can impact the amount of quality sleep you get, and can cause next-day grogginess, along with other potential side effects, such as dry mouth, constipation, and dizziness. The latter can be particularly problematic for older individuals, increasing their risk of mental confusion and falling.

What’s more, research published in the JAMA Internal Medicine shows that repeated use of anticholinergic medications (including first-generation antihistamines like doxylamine or diphenhydramine) can increase a user’s risk of dementia.

“It’s strongly recommended that elderly patients avoid taking OTC sleep aids, especially the ones with antihistamines,” Dr. Alapat says. Older adults generally metabolize drugs differently than younger ones, which means a drug can sometimes linger longer in their systems. And because they tend to take more medications than younger patients, drug interactions are more likely.

In general, experts don’t recommend using Benadryl (or any form of diphenhydramine) for sleep more often than for the occasional sleepless night. The same goes for doxylamine, the tablet formulation of the Unisom sleep aid.

“The antihistamine diphenhydramine [found in Benadryl] is only approved for management of short-term or temporary sleep difficulties, particularly in those people who have problems falling asleep,” Dr. Kimble says. “The data for use in long-term or chronic insomnia is poor. Patients can become tolerant to the sedative effect within days of taking it repeatedly, and it is usually not recommended for more than three days in a row.”

Dr. Kimble recommends that if you need Benadryl for more than 14 days, you should contact your healthcare provider for medical advice.

When would a prescription sleep aid be recommended?

If you’re having trouble sleeping, reach out to your healthcare provider. In some cases, a physical exam can shed light on an underlying medical condition that is interrupting your sleep (for example, sleep apnea, gastroesophageal reflux disorder, or restless leg syndrome).

Your doctor can also discuss with you whether you’re a good candidate for prescription sleep medicines, such as Ambien (zolpidem) or a benzodiazepine like Restoril–all of which are controlled substances. Ambien is typically prescribed short-term for people who have difficulty falling asleep, while Ambien CR may be prescribed short-term for individuals who have trouble falling and/or staying asleep. Ambien and related drugs have fewer side effects than benzodiazepines—however, there is a black box warning alerting patients to the possibility of dangerous activities such as sleepwalking or sleep driving. Benzodiazepines may be prescribed in patients with chronic insomnia, but have many side effects.

Although nonbenzodiazepines like Ambien, Lunesta (eszopiclone), and Sonata (zaleplon) have fewer adverse effects than benzodiazepines, there is a risk of dependence with both classes of prescription sleep medications.

To help yourself get a good night’s sleep—with or without sleep aids—you should practice good sleep habits. “Often these small life changes yield the biggest benefits,” Dr. Kimble says. Start with these tips:

Establish a regular sleep pattern. Go to bed and get up at about the same time daily, even on the weekends.
Make the bedroom comfortable for sleeping. Avoid temperature extremes, noise, and light.
Engage in relaxing activities before bedtime. For example, take a warm bath or read.
Avoid stimulation at bedtime—that means shutting off the TV, computer, and phone.
Stay away from substances like caffeine, nicotine, and alcohol. All of these can keep you awake, or prevent you from having a good night’s sleep.