Which Over-The-Counter Sleep Medication Is Right for You?

Different sleep medications have different adverse effects

Man sleeping

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It's 3 a.m., but instead of dreaming the night away, you're mentally making a grocery list, balancing your budget or rehearsing your presentation. After a few nights of tossing and turning, you know you've got to do something. But now you're faced with another predicament. How do you decide what kind of over-the-counter (OTC) sleep medication can relieve your insomnia?

There are two categories of OTC sleep medications from which you can choose: diphenhydramine and doxylamine.


Active ingredients: Diphenhydramine citrate, diphenhydramine hydrochloride, diphenhydramine tannate

Common brand names: Simply Sleep, Nytol, Sominex, 40 Winks. Generics are available.

How it works: Diphenhydramine is an antihistamine with sedative properties, which slow down the nervous system and make it easier to sleep. It's the same drug that's commonly used to treat cold and allergy symptoms like sneezing and runny nose.

Typical dosage: 50 mg at bedtime

Important information: Adverse effects may include dizziness, nausea, headache, dry mouth and difficulty urinating. If you experience any of these effects, call your physician. Severe allergic reactions may include difficulty breathing; facial, lip, tongue or throat swelling as well as hives. These adverse effects require immediate attention.

If you are taking any other medicine for insomnia, anxiety or depression, get your physician's advice before taking diphenhydramine. If you are using a monoamine oxidase inhibitor (MAOI), which is a class of psychiatric medications, do not take diphenhydramine.


Active ingredient: Doxylamine succinate

Common brand names: Unisom SleepTabs, Nighttime Sleep Aid. Also comes in generic form.

How it works: Like diphenhydramine, doxylamine is an antihistamine with sedative qualities.

Typical dosage: 25 mg 30 minutes before bedtime

Important information: Take doxylamine only when you plan to sleep seven or eight hours. If you need to get up sooner, you might be drowsy until the drug has a chance to wear off. Taking doxylamine in unison with Nyquil may cause adverse effects.

Adverse effects might include dry mouth, nose and throat; nausea; chest congestion; headache; excitement and nervousness. Let your physician know if these conditions are severe or lingering. Call your physician immediately if you experience changes in vision or have problems urinating.

If you think you need to take doxylamine for more than two weeks, consult your physician first.

Additional Cautions

Be careful about choosing sleep aids like Tylenol PM, Advil PM or any generic nighttime medication that also contain acetaminophen or ibuprofen. If you're not specifically looking for a pain reliever along with a sleep aid, it's best to avoid unnecessary medication.

Avoid alcohol while taking doxylamine and diphenhydramine because alcohol exaggerates the sedative effects of these drugs.

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Article Sources

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  1. Abraham O, Schleiden L, Albert SM. Over-the-counter medications containing diphenhydramine and doxylamine used by older adults to improve sleepInt J Clin Pharm. 2017;39(4):808–817. doi:10.1007/s11096-017-0467-x

  2. HelpGuide. Sleeping Pills and Natural Sleep Aids. June 2019.

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