Its annoying how the biggest consideration in whats get OTC'd is how useless it is (only slightly above homeopathic level useless) or how painful the overdose is (more painful -> sure, knock urself out) and little recreational potential it has (see point 2 + again, knock urself out) with a few radical exception(s)

Edit: if its pharmacologically active and effective for "an" indication, its fun/euphoric, and super safe? --> illegal or controlled vs snake oil, no fun, narrow or easily surpassed and potentially catastrophic therapeutic window --> sure, knock urself out