I've had Botox on the chin 3 times in total. It lasted about 4-5 months. I had some jaw muscles, so the first time I got it, my friends saw it, and I did it myself. Will the effect last longer? It was like that when I was consulting, so it 's been about a year since I got hit 3 times and didn't, but my muscles just don't seem to come up like before .