Been on HU going on 8 years, same dose, 500 mg every day plus extra 500 on M-W-F. My hair dresser, who hadn't seen me for a few years, said this month, "Your hair looks good. It's thicker!" That was my sense, too, but I was afraid it was wishful thinking. Many of us do have initial hair thinning, but it can get better as our bodies get used to it.