apparently no will power.
At all.
Eh, I used to think that way, but these drugs have convinced me there is a large percentage of this that is just chemical/hormonal, and varies from person to person. If one person's body chemistry tells them "I'm full" much sooner than does someone else's, it isn't really fair to just say it's a matter of willpower.
There also are people whose bad habits lead them to keep eating even when their body is not telling them to eat, and the drugs apparently don't work on them.
If the drugs reduce hunger pangs and let people eat a lot less and still be "full", that's probNly a good thing. Much better than just being obese, anyway.