4-6 hours: Typically, the effect of Benadryl (diphenhydramine) is 4-6 hours. It may be longer in people with liver disease.
Answered 11/30/2018
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7 doctors weighed in across 2 answers
A doctor has provided 1 answer
6 doctors weighed in across 2 answers
A doctor has provided 1 answer
A doctor has provided 1 answer
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