Clortermine (Voranil) was developed in the 1960s by Ciba and is an amphetamine-class anorectic drug. It is the 2-chloro analog of phentermine, the better-known appetite suppressant, which is the positional 2-chloro isomer of chlorphentermine. Similar to chlorphentermine, clortermine induces very low levels of self-administration in animals and, as a consequence, it possibly does not function on dopamine. It can instead serve as a releasing agent of serotonin and/or norepinephrine.