system
Given the following post, respond as if you're commenting on Reddit:
human
Why are appetite suppressors so hard to discover and make useful for dieters when most side-effects of medication is 'loss of appetite?'

I've taken medication in the past that has completely killed my appetite. This seems to be a common side-effect of many substances, yet a pill to help people stop feeling so hungry is something that doesn't seem to exist and most diet pills have horrible GI side-effects.  Why does this continue to elude us?
gpt
Layman here, but it's hard to find something that ONLY kills appetite. For example, adderall (levoamphetamine and dextroamphetamine salts), which is prescribed in the treatment of ADHD, kills the appetite, but it also causes euphoria, insomnia, mania, and can be harmful to your cardiovascular system. Same for ephedrine. 

That said, for some severely obese patients, doctors may prescribe a medication for its off-label appetite suppressing effect.