It took about 2 -3 months to get to grey - it was also intensely frizzy! I had been wearing a wig and lots of people didn't know I had lost my hair, so when I dropped the wig, there were a lot of looks of the WTH - why has she got that awful perm and gone grey?? Didn't care! It was MY hair. Every time I got it cut, which I did quite frequently at first, the frizz was less apparent and the colour more apparent. So even if you had long hair and are keen to get it that length again, there is some sense in keeping it short at first as you progressively cut out what is fairly damaged first growth. Good luck!