Question: what over the counter medication makes you sleepy?
Answer: Diphenhydramine (Benadryl, Aleve PM, others). Diphenhydramine is a sedating antihistamine. ...  Doxylamine succinate (Unisom SleepTabs). Doxylamine is also a sedating antihistamine. ...  Melatonin. The hormone melatonin helps control your natural sleep-wake cycle. ...  Valerian.