You are probably correct, I honestly do not know. What I meant is that there is an association between melatonin and sleep and there is _some_ research on it as

You are probably correct, I honestly do not know. What I meant is that there is an association between melatonin and sleep and there is _some_ research on it as an effective medicine but the quantity of it (to my untrained eye) is limited. So when people take it they generally take it as an over-the-counter supplement with some hope for uncertain effects because "it's the thing in the body that regulates sleep". Thus the quotes around "drug".