Target has Simply Sleep Non-Habit Forming Nighttime Sleep Aid Caplets - Diphenhydramine HCI - 100ct on sale for $11.04. - Fall asleep and wake up feeling refreshed with SIMPLY SLEEP Nighttime Sleep Aid Caplets. Specially formulated to help you sleep when pain isn't what's keeping you up, each caplet contains 25 mg of diphenhydramine hydrochloride. This nighttime sleep aid is suitable for adults and children 12 years and older to help relieve occasional sleeplessness. From the makers of Extra Strength TYLENOL PM, SIMPLY SLEEP is designed to relieve occasional sleeplessness and is non-habit forming when used as directed.