I've been getting square jaw Botox for 10 years haha
I got it all the time with a domestic product, but I didn't develop resistance, and once I got it, it seems to last for about 6 months. Square jaw Botox is highly recommended. There were no side effects, and it feels good to be aesthetically slimmer.
When getting chin botox, it is recommended to go to a place where three or four injections are given for each side of the chin. Occasionally, in some hospitals, they just plug it in once and put it all in. It was really bad. lol