NYTOL Extra Strength Sleep Aid Tablets : Nytol Sleep Aid Tablets are a better way to sleep you better. Nytol's major ingredient Diphenhydramine to help you sleep better at night. Nytol is used for relief of sleeplessness when falling asleep can be difficult due to fatigue, over-work or tiredness. The effects can last up to 6 hours. Plus, the quickgel capsules make it work even faster!