It is targeting mu opioid receptors, mentioned in the article as "morphine receptor." It may not contain morphine, chemically, but neither does oxymorphone, it

It is targeting mu opioid receptors, mentioned in the article as "morphine receptor." It may not contain morphine, chemically, but neither does oxymorphone, it's only similar.. the only drug mentioned that actually contains morphine, ie. is morphine based is heroin. But having side chains and other additions can totally change a drugs' effects. Morphine-based is a poor distinction.