It took about 6 months on the special shampoo plus vitamins for mine to start growing back in. It reached just long enough to not be annoying (and I was off Depakote) and I had gyn surgery and my hormones got all messed up and I lost hair again. I started getting THAT back and had a hysterectomy and my hair fell out again. Almost 3 years later it seems to be all better.

For me my hair seems to be really picky about what is going on in my body.