The chemicals in permanent and semi-permanent hair dyes are not highly toxic. Most research, although limited, shows it's safe to colour your hair while pregnant.
Some studies have found that very high doses of the chemicals in hair dyes may cause harm. However, these doses are massive compared with the very low amount of chemicals you may be exposed to when colouring your hair.
Using hair dye when you're pregnant
You may decide to wait to dye your hair until after the first 12 weeks of pregnancy, when the risk of chemical substances harming the baby is much lower. If you're colouring your hair yourself, you can reduce the risk further by making sure you:
- wear gloves
- leave the dye on for the minimum time
- work in a well-ventilated room
- rinse your scalp once the dye is applied
Highlighting your hair, by putting the dye only on to strands of hair, also reduces any risk. The chemicals used are only absorbed by your hair, and not by your scalp or bloodstream.
Semi-permanent pure vegetable dyes, such as henna, are a safe alternative.
Do remember that pregnancy can affect your hair's normal condition. For example, your hair may:
- react differently to colouring or perming than it usually does
- become more or less absorbent, frizzy or unpredictable
It's always a good idea to do a strand test first using the hair dye or treatment you intend to use. Speak to your hairdresser for advice.
Using hair dye while you're breastfeeding
While information about hair treatments while breastfeeding is limited, it's thought to be fine to dye your hair while you are breastfeeding.
Very little of the chemicals used in hair dye enter your bloodstream, so it's very unlikely that a significant amount will be passed on through your breast milk.