23-05-2025
This Common Allergy and Sleep Aid May Be Quietly Raising Your Dementia Risk
If you've ever reached for a quick fix for allergies, a cold, or a sleepless night, chances are you've taken diphenhydramine. It's the active ingredient in well-known over-the-counter meds like Benadryl, Tylenol PM, and many generic nighttime formulas. But National Geographic reported that scientists say prolonged use could come with serious cognitive consequences.
Diphenhydramine is one of the most widely used first-generation antihistamines. It's been FDA-approved since 1946 and remains a go-to remedy for everything from seasonal allergies to insomnia. But newer research warns that long-term, daily use may increase your risk for developing dementia or other neurodegenerative conditions.
'Taking diphenhydramine is not without risk, especially as the duration of use increases,' says Dr. Sayantani Sindher, a pediatrician and allergist at Stanford Health Care. Alongside cognitive decline, extended use of the drug has been linked to weight gain, memory problems, and poor sleep quality. Some users also experience anxiety, confusion, or slower reaction times—even when taking recommended doses.
The problem isn't just the drug's pharmacology but also its pervasiveness. Diphenhydramine shows up in everything from allergy meds and sleep aids to cold and flu treatments, often without users realizing how much they're taking. 'It's one of the most commonly abused medications in the United States,' says Sindher.
According to the Consumer Healthcare Products Association, these medications 'are not intended for long-term use,' and responsible dosing is critical. But for millions of Americans dealing with chronic symptoms, dipping into the medicine cabinet becomes routine, and that's where the risk creeps in.
Earlier this year, The World Allergy Organization Journal declared that diphenhydramine is at the end of its life cycle. It suggested that the drug no longer be available over the counter.
With safer, non-sedating antihistamines now widely available, doctors suggest reconsidering what's in your daily rotation. Because when it comes to brain health, long-term convenience may not be worth the cost.
