I worked as a prison nurse forever.

Have you seen the track marks from heroin users? well, that is caused from the talc powder they use to cut the drug with. That stuff is NOT tissue friendly, and does a great deal of damage. Most folks thought it was from dirty needles, or bad technique, but nope, its the stuff they cut it with.

I have know diabetics with dents, and seen chemo patients with baby smooth skin. Some has to do with genetics, and collagen levels, and some has to do with what they put in the needle.

Me? I have a couple of dent on my tummy from picking my fav spot to shoot. I am gonna have to start moving it over. My legs are lumpy, but not dented. Stopped using my arms, and my butt can handle it.