i died my hair in first tri before i found out, and i told the doctor and she said it should be fine but if i wanted to do it again to make sure that you go to a salon because they can do it like the other girls said, not touching your scalp, if you really cant afford the salon cause i know their crazy prices ( especially here in canada) to not bleach your hair or if you can get someone to do it for you with a brush and just not touch your scalp with the dye. If it does dont worry to much just be careful and get fresh air and dont do it often, if you can live with waiting till later in 2nd tri its best, 3rd and 1st tri arent good to dye your hair in if you do it at home. But rarely is it a huge concern.