However, agomelatine was not approved in the US due to clinical trials not showing effectiveness (withdrawn by the drug company after phase III), although regular melatonin is super easily available here and I've heard some people say it helps. For a good analysis it is important to get access to unpublished studies submitted to the FDA. I don't have links but I think there are a couple that have done that.

Edit: Looks like they did include some unpublished studies at least.