Link: https://slatestarcodex.com/2013/09/28/sleep-now-by-prescription/

Ramelteon isn't a bad drug. It's just that its very existence stands as a condemnation of the entire medical system.

All sleep medications have to straddle a very fine line between "idiotically dangerous" and "laughably ineffective", and Ramelteon manages better than most. It outperforms placebo, it's not addictive, it won't sap your ability to sleep without it, and it doesn't screw up your brain so badly that its unofficial mascot is a hallucinatory walrus.

How does it do it? Ramelteon is the first melatonergic drug, selectively binding to MT-1 and MT-2 melatonin receptors. Binding to melatonin receptors presumably mimics the effect of the natural hormone melatonin which is believed to serve a sleep-promoting role.

Now, you might ask yourself – the natural hormone melatonin is available as an over-the-counter supplement costing a couple cents per pill in every drug store, and provably quite safe and effective. Why would anyone go through the trouble of creating a drug that mimics its action? Especially if a month's supply of the drug costs around $100 – which it does.