Comparing Over-The-Counter Sleep Medications

If it's 3:00 a.m. and your mind is ticking away⁠—making grocery lists, balancing your budget, or preparing tomorrow's to-do list—your insomnia is likely nothing to worry about. However, if this continues for several nights, it may be reasonable to reach for an over-the-counter (OTC) sleep remedy .

There are four OTC sleep remedies you might consider: Two are early-generation antihistamines with sedative properties and the other two are natural remedies believed to aid with sleep.

Diphenhydramine

Diphenhydramine is an antihistamine typically used to treat allergies. It has sedative properties that last for up to seven hours. Diphenhydramine is the active ingredient in Benadryl, and is found in other over-the-counter (OTC) cold-and-flu remedies.

There are several versions of diphenhydramine with similar chemical properties and effects. These include diphenhydramine citrate, diphenhydramine hydrochloride, and diphenhydramine tannate, none of which are inherently better or worse than the other.

Simply Sleep, Nytol, Sominex, and 40 Winks are just some of the OTC sleep products in which diphenhydramine is the active ingredient. Generics are also available.

Dosage

The recommended dose of diphenhydramine for adults and children 12 and over is 50 milligrams (mg) at bedtime. Diphenhydramine citrate may require a dose of up to 76 mg.

Diphenhydramine should only be used in younger children under the direction of a pediatrician. It should never be given to children 2 or younger.

When taken as directed, oral diphenhydramine is unlikely to be addictive. However, persistent insomnia is a concern and poses serious health risks, including an increased risk of high blood pressure, type 2 diabetes, and congestive heart failure. 

Side Effects and Risks

In addition to sleepiness, common side effects of diphenhydramine include nausea, headache, and dry mouth. Most will be relatively mild and resolve within 24 hours. However, if they persist or are severe, stop taking the drug and let your doctor know. You should also call your doctor if you have trouble urinating.

If you are on medications for anxiety or depression, get your physician's approval before taking diphenhydramine. You should never take diphenhydramine with a type of antidepressant called a monoamine oxidase inhibitor (MAOI); doing so may cause seizures, hallucinations, and a severe drop in blood pressure.

Diphenhydramine should never be taken with alcohol. If you experience daytime drowsiness after taking diphenhydramine, don't drive or use heavy machinery until you feel fully alert again.

When taken as directed, oral diphenhydramine is unlikely to be addictive. However, persistent insomnia is a concern and poses serious health risks, including an increased risk of high blood pressure, type 2 diabetes, and congestive heart failure. 

Doxylamine Succinate

Doxylamine succinate is also an antihistamine with sedative properties. Popular sleep aids containing doxylamine succinate include Unisom SleepTabs, Wal-Som, and Nighttime Sleep Aid. It is also available in generic form.

Dosage

The recommended dose of doxylamine succinate for adults and children over 12 is 25 mg 30 minutes before bedtime. It should never be given to children under 12.

Side Effects and Risks

In addition to sleepiness, common side effects of doxylamine include nausea, chest congestion, nervousness, excitability, and a dry mouth, nose, or throat. Let your physician know if these conditions are severe or linger. Call your doctor immediately if you experience changes in vision or have trouble urinating.

Doxylamine succinate should never be taken with alcohol or another medication that causes sleepiness (such as cold-and-flu remedies). The use of doxylamine succinate with an MAOI antidepressant is contraindicated.

Doxylamine succinate is as effective as diphenhydramine but tends to work longer. For this reason, you shouldn't take it the night before a heavily scheduled morning and only if you intend to sleep for at least seven to eight hours. Even then, you shouldn't drive or use heavy machinery until any wooziness passes.

As with diphenhydramine, contact your doctor if you need to take doxylamine more than three times weekly or if insomnia persists.

Melatonin

Melatonin is a naturally occurring hormone that helps regulate the sleep-wake cycle. There are two types of melatonin sold as an OTC remedy: one that is manmade and another that is derived from the pineal gland of animals.

The effectiveness of melatonin for sleep varies. Some people claim that it works and leaves them feeling refreshed the next morning. Others derive no benefits.

On the downside, the effect appears to wane the longer that you take melatonin. As such, melatonin should only be considered a short-term remedy when needed.

Dosage

There is no melatonin dose agreed to be universally effective. Generally speaking, higher doses deliver better results.Most melatonin manufacturers recommend between 0.5 mg and 3 mg 30 minutes before bedtime.

Due to the lack of safety research, melatonin should not be given to children, pregnant women, or nursing mothers.

Side Effects

Melatonin is likely the safest OTC sleep aid. Excess melatonin is quickly cleared and does not accumulate in the body. Side effects may include headache, nausea, and vivid dreams, but these are rare.

Valerian Root

Valerian root (Valeriana officinalis) has been used for centuries to treat insomnia. It contains a substance known as valerenic acid believed to affect gamma-aminobutyric acid (GABA) receptors in the brain. GABA is responsible for tempering nerve signals and, by doing so, may delivering a calming, sedative effect.

Despite its long-standing use in traditional cultures, the effectiveness of valerian root in treating insomnia is uncertain. According to a 2015 review of studies in Sleep Medicine Reviews, valerian root (and similar "calming" herbs like chamomile or kava) had no discernible effect on insomnia.

Dosage

There is no recommended dose for valerian root. Most valerian supplements are formulated in doses ranging from 300 mg to 600 mg and are considered safe within this range.

Due to the lack of safety research, children, pregnant women, and nursing mothers should not take valerian root.

Side Effects and Risks

Side effects of valerian root tend to be mild and may include headache, dizziness, itchiness, upset stomach, dry mouth, vivid dreams, and daytime drowsiness.

Although rare, liver damage has been known to occur, usually due to the overuse of valerian root or the use of "wild-crafted" dried root (which may be contaminated with heavy metals, fertilizers, and other toxic substances).

A Word From Verywell

Insomnia doesn't always require medication. In fact, improved sleep hygiene often is all that's needed to get a good night's rest. This includes not eating before bedtime, turning off electronics at least an hour before sleep, keeping the temperature cool, and ensuring that the bedroom is as dark and quiet as possible.

If insomnia persists despite your best efforts, see a doctor. A prescription sleep aid can be very useful in treating occasional insomnia if used correctly and with supervision.