During pregnancy, a person may worry that the chemicals in hair dye could harm their fetus. However, the small amount of chemicals absorbed should not be harmful.

Hair dyes can contain potentially harmful chemicals. The skin can absorb these chemicals through the skin during application to the hair.

However, if used correctly, the quantity of chemicals absorbed during the hair dyeing process should not be harmful to a fetus.

Read on to learn more about the safety of using hair dye while pregnant, hair dye alternatives, and the safety of other hair treatments during pregnancy.

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Although limited research is available, researchers believe it is not harmful for a person to dye their hair while pregnant.

The American College of Obstetrics and Gynecology states that many experts consider hair dye to be nontoxic to a fetus. Based on animal studies, the scalp only absorbs small amounts of the chemicals.

There are different types of hair dye a person can use, including:

  • permanent
  • semipermanent
  • temporary

Permanent dyes may contain stronger chemicals than semipermanent or temporary dyes. However, there is no evidence to suggest that the permanency of a hair dye makes it more harmful to a fetus.

Research from 2018 found that females who dyed their hair prepregnancy had a higher chance of their baby having a low birth weight.

However, researchers do not mention how frequently people dyed their hair before becoming pregnant. Additionally, they did not collect data regarding hair dye use during pregnancy.

Hairdressers and cosmetologists

There is no recommendation for hairdressers or cosmetologists to stop working while pregnant. A 2015 meta-analysis notes that hairdressers and cosmetologists may have a slightly higher risk of:

However, many different factors could contribute to these slight increases, such as:

  • ventilation
  • working conditions
  • working hours
  • exposure to various chemicals

A person should perform a patch test every time they dye their hair. A patch test involves applying a small amount of dye to a person’s skin before dyeing their hair.

Patch tests can help see if a person is allergic to any ingredients in the hair dye. Allergic reactions to hair dye can cause serious symptoms, such as swelling of the throat and difficulty breathing.

The Food and Drug Administration (FDA) recommends the following steps for a patch test:

  1. Apply a small amount of dye to the inner elbow or behind the ear.
  2. Leave the dye on the skin for 48 hours.
  3. If there is a rash after 48 hours, do not use the hair dye.

If a hairdresser is dying a person’s hair at a salon, they should perform a patch test.

The FDA also recommends the following safety tips when dyeing hair at home:

  • Always follow the instructions on the package.
  • Always wear gloves.
  • Never use hair dye to dye eyebrows or eyelashes, as this can cause serious injury or blindness.
  • Rinse the scalp thoroughly with water after dyeing hair.
  • Never mix two different hair dyes.
  • Do not scratch or brush the scalp for 3 days before dyeing hair.
  • Do not dye hair if the scalp is irritated, sunburned, or damaged.
  • Wait at least 2 weeks after relaxing, perming, or bleaching hair before dyeing it.
  • Read the list of ingredients and make sure the dye does not contain substances that have caused problems previously.

People should also avoid leaving the hair dye for longer than recommended. The United Kingdom’s National Health Service (NHS) advises leaving the dye on the hair for the minimum time recommended on the box.

In addition, they suggest that a person may wish to wait until after the first 12 weeks of pregnancy. This is when the risk of chemicals harming the fetus is much lower.

To keep exposure to chemicals to a minimum, some doctors suggest that people wait until after their pregnancy to dye their hair. Others may recommend waiting until after the first trimester.

If a person is using hair dye at home, they should try and keep the space well ventilated. They can do this by opening windows and doors or using ceiling fans.

A person can also reduce exposure to chemicals by highlighting their hair rather than dyeing it. Highlighting hair involves using a cap that covers the scalp, which can reduce the amount of dye that reaches a person’s skin.

To reduce their exposure to chemicals, hairdressers and cosmetologists can:

  • use protective equipment, such as gloves
  • work in well-ventilated areas
  • avoid eating and drinking in the workplace
  • take frequent breaks
  • practice safe handling and storage of hair care products

If a person does not want to use chemical dyes during pregnancy, alternatives are available.

The NHS notes that certain dyes are vegetable-based or use henna. Henna is a natural dye that comes from the leaves of the henna tree. There are also chemical hair dyes that are free from bleach or ammonia.

A person can use natural box dyes in the same way they use chemical hair dye. Henna comes in powder or cream forms. If a person is using powdered henna, they will have to mix it with water to form a paste before application.

Natural dyes may not be as long lasting as chemical dyes and may fade sooner. They may also not produce as strong a color as chemical dyes or have as many colors available.

Pregnancy can affect a person’s typical hair condition. The NHS advises performing a strand test before applying the dye to the rest of the hair.

Here are some frequently asked questions about the use of hair dye and other hair treatments during pregnancy.

If a person is concerned about using hair dye or undergoing hair treatments during pregnancy, they should speak with a healthcare professional.

Will using hair dye increase the chance of pregnancy loss?

The nonprofit organization Mother To Baby states that no studies on human pregnancy suggest that using hair dye during pregnancy can increase the chance of pregnancy loss.

It points out that the amount of chemicals the scalp may absorb is very low under typical use and very little would reach the fetus.

Is hair dye safe to use whilst breastfeeding or chestfeeding?

Information from Mother To Baby notes that the effects of hair dye on a nursing baby are unknown. However, they note that hair dye is unlikely to affect them.

The NHS states that only a very small amount of the chemicals in hair dye will enter the bloodstream. As a result, a person will not be able to pass on a significant amount through breast milk.

Is it safe to bleach the hair during pregnancy?

There is no evidence to suggest that bleaching the hair could be harmful during pregnancy. Mother To Baby states that no hair treatments are currently known to be dangerous to a fetus.

Is it safe to perm the hair or use relaxers during pregnancy?

Hairdressers use chemicals to perm or relax a person’s hair.

A 2021 study explored the relationship between chemical-associated hair product use during pregnancy and gestational age at delivery. It found no difference in birth weight or premature birth among people who used chemical perm or relaxer products 3 months before pregnancy or while pregnant compared with those who did not.

There is currently no evidence to suggest that a person should not perm or relax their hair during pregnancy.

If a person has any questions or worries about hair treatments during pregnancy, they should speak with a healthcare professional.

There is no evidence to suggest that any hair treatment, including hair dye, is harmful during pregnancy. As a precaution, a doctor may recommend that a person waits until after their pregnancy, or the first trimester, before dyeing their hair.

A person should always perform a patch test before dyeing their hair. Additionally, a person should follow certain precautions to limit their exposure to hair dye chemicals.

Various vegetable or plant-based dyes are available if a person does not want to use chemical hair dyes. However, these dyes may fade more quickly or produce a less vibrant result.

If a person has any concerns about hair treatment during pregnancy, they should speak with a healthcare professional.