When you reach for that bottle of diphenhydramine, a first-generation antihistamine commonly found in over-the-counter sleep aids and allergy meds. Also known as Benadryl, it's one of the most widely used drugs in medicine cabinets across the U.S. and UK. But what seems like a quick fix for insomnia or a runny nose can quietly harm your brain, heart, and long-term health—especially if you're over 65.
Diphenhydramine is an anticholinergic drug, a class of medications that block acetylcholine, a key brain chemical for memory and muscle control. That’s why it makes you drowsy—but it also scrambles your focus, slows your reflexes, and increases your risk of falls. Studies from the Journal of the American Geriatrics Society show that long-term use in older adults is linked to a higher chance of dementia. And it’s not just seniors: healthy adults using it nightly for weeks can develop tolerance, meaning they need more just to fall asleep. Worse, mixing it with alcohol, opioids, or even some antidepressants can slow your breathing to dangerous levels.
Many people don’t realize that doxylamine, another common OTC sleep aid found in Unisom, works almost identically to diphenhydramine. Both are in the same drug family, carry the same risks, and are often swapped out as "alternatives"—but neither is safe for regular use. Even melatonin or valerian root, which show up in some of our posts as safer sleep options, are better choices because they don’t mess with your brain’s natural chemistry. And if you’re using diphenhydramine for allergies, there are newer antihistamines like loratadine or cetirizine that won’t leave you groggy or confused.
Here’s the truth: if you’ve been taking diphenhydramine for more than a few nights in a row, you’re not solving your problem—you’re masking it. Insomnia? Allergies? Itching? There are real solutions that don’t come with a hidden cost to your cognition or heart rhythm. Below, you’ll find real comparisons between diphenhydramine and its alternatives, breakdowns of who’s most at risk, and clear guidance on how to step away safely. No fluff. No marketing. Just what you need to know before your next pill.
First-generation antihistamines like Benadryl significantly increase fall risk in older adults. Learn why they're dangerous, which safer alternatives exist, and how to prevent falls through medication changes and home safety.
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