07/29/2026
Benadryl (diphenhydramine) is a commonly used antihistamine, but like any medication, it's important to understand how it works and when it's appropriate to use.
Because it crosses the blood-brain barrier, diphenhydramine can cause drowsiness and, in some cases, confusion, delirium, or hallucinations, particularly in children, older adults, or when taken in higher-than-recommended doses. It's also generally not recommended for long-term daily use unless directed by your healthcare provider.