I am at 9% now but even when I was at 6-7% I still preferred using 1.5's. One time I used a 1" and got a bubble(maybe a abcess...not sure) in my ass. It went away after a week or two. I was probably at 10-11% bf when this happened though... But since then I stick to 1.5" in the glutes and 1" for quads and delts.