Save Your Brain: Say No to Antihistamines for Sleep

Save Your Brain: Say No to Antihistamines for Sleep

Standard disclaimer: consult your personal physician for all matters relating to your personal health. This is intended to be descriptive of the science.

It was a crazy day at work, you did the laundry and dishes, got the kids to bed, and look down at your phone to check the time. 9:30. Sh*t. You have a big day tomorrow and evidently no time for yourself at all. You’re exhausted but know you have no chance of falling asleep at a reasonable hour—that post-lunch coffee was the solution at the time, but its effects are lingering way past their service period. Ah—but that Benadryl or ZzzQuil (diphenhydramine hydrochloride) under the bathroom sink will do just the trick. Bring on the drowsiness.




Don’t. Please don’t. Our objection here at Proper has nothing to do with “chemicals" or that it’s not effective—it certainly makes you drowsy (though tolerance builds quickly and with a 9-hour half-life in adults, that drowsiness is likely to continue into the morning). As a first-generation antihistamine, it crosses the blood brain barrier easily where it acts as a histamine H1-receptor antagonist, reducing wakefulness, arousal, cognition, and memory while also being highly anticholinergic. Helps you fall asleep? Sure thing. But what about over the long run?

As a general rule we should be on high alert when we see something is anticholinergic. Unfortunately, that's exactly what these first-gen antihistamines are. Why is that concerning?

Because long-term use of anticholinergics is associated with increased dementia risk.


From the Alzheimer’s Drug Discovery Foundation's Cognitive Vitality Report on Diphenhydramine:

Potential harm to the brain: Long-term anticholinergic use has been associated with increased dementia risk; diphenhydramine can impair many cognitive functions including memory.

Aging and related health concerns: Diphenhydramine may improve sleep but it is unlikely to increase slow-wave sleep; because of increased risk for greater adverse effects, it is listed as inappropriate for use in older adults based on the Beer’s criteria.


We know from The Four Stages of Sleep post that we need as much slow wave deep sleep (N3) as we can. That deep non-REM sleep is when our brains clean themselves, and certain compounds (like Venetron®, which is in all of our formulations) may help with inducing more N3. Diphenhydramine hcl not only does not help with this critical restorative slow-wave sleep, but its anticholinergic properties appear to actively put at risk our brain health. No bueno.

As researchers find more and more evidence that choline is critical to our brain health as we age, it becomes obvious that one of the easiest ways to reduce our dementia risk and keep our brains healthy is by entirely removing those first generation antihistamines from our sleep routines.

Please, stay away from antihistamines for sleep.



Note: Venetron® is a registered trademark of Tokiwa Phytochemical Co., Ltd.