Imagine someone developed a drug that relaxes you without any harmful side-effects. In fact, all the side-effects are beneficial. The drug helps you heal faster, it improves your disposition, it helps you sleep better, it even helps you read faces better.
This drug does not exist because we don't need it. Our own bodies produce oxytocin, which has all the effects I've described here, plus many more.
How can you get your body to release oxytocin into your blood stream? It's not that hard.
Read all about it here.