I've had stretch marks on my arms, forearms and shoulders ever since I was 12 years old. I gained a lot of weight as a pre-teen and teenager and have since lost most of it. I am now 23 and left with these horrible marks. I am an african american female so I am hesitant about using lasers. I've read that carboxytherapy is "the best development in stretch mark treatment in years." Does it really work? Will it work on old stretch marks?