I had one session of the girl group injection in my upper arm, probably one set of four shots, back in the summer of 2017. It works well. Even if I gain weight, my upper arms don't become as bulky as they used to.
I'd like to get it again.. But when you get the girl group injection, your arms swell up for a month or two, so I pass.. It might be better to just get liposuction... Still, I recommend it for people who are afraid of surgery. And if you're going to get it, don't do it in summer; get it in advance. Your arms swell a lot.