There was an empty box of these in my childhood home until my parents moved in the mid-00s.
They dulled your taste buds so food would be less tempting. They got fairly popular in the 70s after the US decided that maybe putting amphetamines in OTC diet pills wasn't a great idea, and people were looking for other magic weightloss products.
South park had an episode about a guy who advocated to give people aides to help them with getting fit and organize their life. Except it sounded like the dude went around saying he wants to give aids to children