Is Diphenhydramine as a Sleep Aid Bad for Your Health?

Getting a good night’s sleep is one of the pillars of good health, but for many people it is a real struggle. They toss and turn, worrying that they won’t be able to fall asleep at all. It is no wonder over-the-counter (OTC) sleeping pills containing diphenhydramine are so popular. They are widely available and may help people feel drowsy.

Are OTC Sleeping Pills Safe Enough for Regular Use?

Q. I started taking OTC sleep aids when I was working a late shift. Even when I got back to a more normal work pattern, I had to rely on diphenhydramine to fall asleep.

Sometimes I take two or three pills to stay asleep but then I wake up feeling groggy. Are these OTC pills bad for me?

How Does Diphenhydramine Affect the Brain?

A. Diphenhydramine (DPH) is a sedating antihistamine. It is the ingredient in the allergy medicine Benadryl. DPH is also the “PM” component of pain relievers like Advil PM, Aleve PM, Excedrin PM and Tylenol PM.

Some people complain of “brain fog” the morning after taking diphenhydramine. That would be especially likely if you double or triple the dose.

The American Academy of Sleep Medicine recently issued guidelines about DPH (Journal of Clinical Sleep Medicine, Feb 15, 2017):

“We suggest that clinicians not use diphenhydramine as a treatment for sleep onset and sleep maintenance insomnia (versus no treatment) in adults.”

DPH Is an Anticholinergic Drug

Our principal concern with DPH is that it is highly anticholinergic. (We wrote about why that is a problem here.) As a result, we are concerned that regular use of diphenhydramine over the long term might contribute to confusion or memory loss, not just morning-after brain fog (JAMA Neurology, June 1, 2016). It would be better not to rely on OTC sleeping pills with DPH, but you will need to find other ways to get the sleep you need.

What Are the Alternatives to DPH for a Good Night’s Sleep?

Q. I have been taking DPH sleep aids for several years, even though they are not recommended. Sleep is difficult for me, though, and they almost always work within half an hour. There are no side effects that I am aware of.

Part of my problem might be that I read books on my iPad in the evenings, which may be too much screen time. Perhaps I should switch back to paper books. Do you have any other suggestions for safe ways to get to sleep?

A. Diphenhydramine (DPH) is a sedating antihistamine. You might recognize it by the brand name Benadryl. As we noted above, many nighttime (“PM”) pain relievers contain DPH.

Preliminary mouse research published as a preprint on bioRxiv (July 28, 2026) reported that “…chronic DPH use degrades sleep quality…”  Even if it helped sleep, though, we worry about DPH because it is anticholinergic. A study of elderly French people found that that those using any anticholinergic medicine were at risk for declining cognitive performance (British Journal of Clinical Pharmacology, Feb. 2005).

It would be cruel for us to scold you for using DPH and not offer any alternatives. Probably the best-known and best supported alternative treatment is entirely drug-free. It is called cognitive behavioral therapy for insomnia, or CBT-I. Not everyone sticks with it, but for those who do, it can help ease depression as well as insomnia (Journal of Affective Disorders, Dec. 15, 2024).

Sometimes insomniacs may have trouble finding a therapist offering this treatment. They can feel comfortable searching online. A review has found that web-based CBT-I with a therapist is effective at improving sleep (Sleep Medicine Reviews, Feb. 2022).

Learn More

You will learn about other problems associated with DPH plus nondrug strategies for combatting insomnia in our Guide to Getting a Good Night’s Sleep. describes numerous herbs, supplements and bedtime snacks that can be helpful. It also discusses the pros and cons of a range of prescription sleeping pills. In addition to advice on herbs and supplements that can be helpful, this online resource lists a number of medications that might be inadvertently keeping you awake.

If you like to learn through listening, we can offer a couple of informative podcasts based on interviews we have conducted. the most recent is Show 1480: The Sleep Reset: How to Fall Asleep and Stay Asleep. The guest was Dr. Roger Seheult, a sleep medicine expert. You might also be interested in Show 1393: How to Get the Sleep You Need.