Benadryl brain study halted after just 3 volunteers
NCT ID NCT05219604
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study aimed to measure how a single IV dose of diphenhydramine (Benadryl) affects thinking, memory, and alertness over time. Researchers planned to compare effects in middle-aged and older adults. However, the study was terminated early after enrolling only 3 participants, so the findings are very limited.
What this could mean
Our plain-language read of the trial. This is informational only — not medical advice or a prediction.
Active substance
diphenhydramine (Benadryl)
What this could lead to
If successful, this could help doctors better understand how antihistamines like diphenhydramine affect thinking and alertness, especially in older adults.
What could go wrong
The study was terminated early and only enrolled 3 people, so results are very limited and may not apply to the general population.
Disclaimer
Read more
Show less
This is a summary of
the original study
.
Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for CENTRAL NERVOUS SYSTEM EFFECTS OF DIPHENHYDRAMINE are added.
By submitting, you agree to our Terms of use
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Show contact details
Enter your email to view the contact information for this study.
By submitting, you agree to our Terms of use
Locations
-
Dent Neurologic Institute
Amherst, New York, 14226, United States