I took Accutane a LONG time ago when the dosing was much more aggressive (like, 20 years ago). I had some thinning, noticeable only to me. There may have been some drying but even then I colored my hair and swam so much, it would've been hard to notice. It all went back to normal after my six months on Accutane and a growing out period.
The dry skin was a much bigger issue but it's only temporary. If the side effects are unmanageable to you, you can always quit.