Botox and botulisum also does something for the muscle weakness and tendon loss in our bodies and is being used for medical reasons as well. I know a young man who is in wheelchair and because he has weak tone the medical team is considering botox for him. Not sure how it will react exactly but it is supposed to improve his tone and help him stand easier after many treatments. I am interested to see what it does.
Also botulism was used many years ago in my boyfriends eye. He has one that looks the other way. Really cool when you are trying to negotiate a deal with someone but in an attempt to fix it so they would both stay focused they used the botulism, no go, it worked for a short while and then the eye decided it was going to do what it wants to do again. He loves to see if he can freak people out, some get the biggest kick out of it and some nervous about it. He has decided to just leave it alone since he is so used to how it is and it really does not bother him.
I know some substances are not supposed to be in our bodies like botulism but supposedly within certain areas of use it reacts differently, not sure I would ever use it to take wrinkles away but then again if I get any I might change my mind really quick too, depends on where they are and how they look but I would not use it to the point of making myself look like some people who get carried away with it either. Seen some like you said who can't even smile anymore.