When I was 17, I was on Accutane for my horrible acne (if you'd like to call it disfiguring... go ahead... it was terrible, I looked like I had measles), I believe 40 mg a day, and it actually turned my hair curly. Almost 7 years later, and I've never had any bowel issues, though I continue to get emails about lawsuits against Accutane for such issues. The only negative side effect I got from it was a little depression that went away when my skin started clearing up. Considering the hundreds or thousands my parents spent on acne medication for me, Accutane was a real life saver as it was the only thing that ever did anything.
Related to hair, it did indeed turn my hair curly for some odd reason, but the real kicker is that it thickened it INCREDIBLY, especially in the areas where I am now having thinning issues. After several months of taking it, I had hair in my temples that was just as thick as the hair in my sideburns. I couldn't get a comb through my hair (which didn't help my depression) because it was so thick and curly. After going off the medication, my hair remained curly and thick for several years. Over time, it slowly faded back to straight hair which is unfortunately much thinner. My hair is 100% straight now except in my sideburn area in front of and behind my ears and on my neck. 3 years ago, my "horseshoe" hair was wavy, but the hair on my head susceptible to balding was becoming straight and thin. That's when and why I started using Rogaine and ultimately Propecia at 22 years old, and I continue to take it to this day. At 25 now, I can't say that the Rogaine or Propecia have done anything compared to Accutane for me.
Unless I'm mistaken, Accutane is currently banned in the US. If it isn't, I would definitely consider going back on it to be a guinea pig and see if it would make my hair grow in thicker again. Though, what worries me, is that it may be for nothing. I was young and still maturing back when I was on it and now I'm an adult. I haven't ever done research into seeing what age group gets the bowel problems from taking it, but I don't think a life time of crapping myself is worth having a few years of thick, curly hair.
My results weren't typical however, my dermatologist still claims I am the only person she ever put on Accutane that ended up with thick curly hair. If I went back on it today... I don't know if it would have the same results.
I located the old comparison I made back in 2002 or 3. I don't know the dates of the photos, but the one on left was from 10th grade (so I was 15) and the one on right was from 12th grade (I was 17). Although there's mousse in my hair in both pictures... I assure you... there's no trickery going on. My hair really turned that annoyingly curly. It was a real mess to deal with, but so incredibly thick.
Keep in mind, that I wasn't having male pattern baldness or anything else when I was 15... nor when I was 17... so you probably can't see any thickness changes in between the pics...
If, for some reason, a bunch of you are interested, I could go through some old floppy disks and see if I can locate more old photos, but I don't know what good it would do anyone.