Do You Have the Napa Chino?

Coffee can interfere with sleep, but the plus side is that it does wake you up. Caffeine takes 20 to 30 minutes after ingestion to have its full effect. Some people who say coffee puts them to sleep are actually tired and need to sleep. The caffeine doesn't kick in instantly. They fall asleep because they're tired. And then they think the coffee put them to sleep, but it's actually a third factor.