Instruct: Classify Amazon reviews into positive or negative sentiment
Query: It works like a charm

What a wonderful product! Having used melatonin before with little result, I was initially skeptical regarding this product. But WOW! Falling asleep, then staying asleep is greatly facilitated. Even returning to sleep after a middle of the night issue with the kids is possible. And no hangover in the morning. I never want to be without these in my medicine cabinet again!