NYTOL Extra Strength Sleep Aid Quickgels : You want a better sleep! We have Nytol Extra Strength Sleep Aid Quickgels for you. Nytol Sleep Aid Quickgels uses 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!