From (Season 2 Episode 2) “Simpson and Delilah”
Homer discovers a new miracle hair growth formula called Dimoxinil and cheats on some insurance forms so that he can buy some. Homer grows hair overnight and is soon given a promotion at the Springfield Nuclear Power Plant. He gets a new secretary named Karl, who helps him become successful. However, Mr. Burns’ assistant Waylon Smithers becomes jealous of all the attention Burns is giving Homer and discovers that Homer had cheated on the insurance forms. Smithers tries to fire Homer, but Karl claims he cheated on the forms and is fired in Homer’s stead. Bart spills Homer’s remaining Dimoxinil and Homer loses all of his hair. As a result, Homer is demoted back to his old position.