Not medical advice. General education only — not medical advice, and not a substitute for your prescriber or pharmacist. Emergency & crisis resources · How we review content

Why does trazodone make me so drowsy?

Short answer: Trazodone blocks histamine H1 receptors, similar to how antihistamines like diphenhydramine cause drowsiness — this is the mechanism behind its most common side effect.

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See our Drowsiness and Sedation page. This antihistamine-like activity is also part of why trazodone is so commonly used off-label for sleep at low doses, even though it was originally developed and approved as an antidepressant.

Not medical advice. This answer is general and educational. Your prescriber knows your full history and can give guidance specific to you.

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The Medication Companion lets you log doses, sleep, symptoms, and questions for your prescriber — privately, in your browser, no account required to start.

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