Nytol Extra Strength

The active sleep aid ingredient in Nytol Extra Strength is diphenhydramine and is intended for the relief of occasional sleeplessness when difficulty falling asleep is due to fatigue, over-work or tiredness.

Diphenhydramine belongs to a group of medications known as antihistamines, the same active ingredient found in many cold and allergy medications.  The effect of Nytol lasts for up to 6 hours.