Most research says the chemicals found in both semi-permanent and permanent hair dyes isn’t too toxic, and so it’s safe to use during pregnancy. Only very small amounts of hair dye are absorbed into your skin, so that leaves very little that would be able to reach your baby. So, this small amount is not believed to be harmful to your baby.
If you’re worried, think about holding off on coloring your hair until your second trimester. Once your first trimester is over, your developing baby will be less vulnerable. And, you could do highlights or steaks instead of using an all-over hair color. With highlights and streaks, the chemicals in hair dye have almost no contact with your scalp.
Coloring your hair with henna (a semi permanent vegetable dye) is also an option. But henna can be pretty messy, and you have to leave it in for a long time. Plus it can give your hair a red-orange hue that you may not like. If you do decide on using henna in your hair, avoid henna products that come in other colors or are fast-acting: they could contain synthetic chemicals or metallic compounds that may be risky.
If you’re considering whether to color your hair or hold off until after pregnancy, think about if coloring your hair will make you feel good or cause you months of unnecessary worry. If you decide to color your hair, make sure that you wear gloves (many at-home kits come with gloves inside). And, color your hair in a well-ventilated area with fresh air, so that you can reduce your exposure to hair coloring chemicals. Only leave the dye in for the recommended time (no longer), and make sure to rinse all of the color out at the end.