Coloring your hair while pregnant: what precautions should you take?

Hair dye should be used with great caution, especially during pregnancy. While it is not formally prohibited, the chemical substances it may contain should be monitored closely. What are the potential risks and what precautions should you take?

Coloring your hair while pregnant: let’s take a look.

Coloring your hair while pregnant: potential risks

Hair products do in fact contain various chemical substances, some of which are debated in terms of their safety. Most traditional hair dyes contain a combination of chemicals that can pass through the scalp and enter the bloodstream, although the amount remains very small. Ingredients to watch closely include:

• Ammonia: used to open the cuticle and allow pigments to penetrate, it can cause irritation of the scalp and respiratory tract.
• Parabens: these preservatives, suspected to be endocrine disruptors, should be avoided in hair products during pregnancy.
• Resorcinol: this chemical component, found in many hair dyes, can be irritating and may cause allergic reactions.
• p-Phenylenediamine (PPD): frequently used in colorants to achieve dark shades, it is also known for its allergenic potential.

The amount of chemicals absorbed through the scalp during a standard hair coloring is quite low. To date, no study has shown a direct link between using hair dyes during pregnancy and congenital malformations or major complications for the baby.

However, experts recommend caution, especially during the first trimester, a key period of fetal development. It is best to limit hair coloring, oxidative dyes, or any product application that comes into contact with the scalp. Allergic or irritant reactions may also be more common during pregnancy because the skin and scalp become more sensitive due to hormonal effects.

Also avoid:

• Spray products: they are more easily inhaled and can irritate the lungs, especially in poorly ventilated spaces.
• Leave-in color-depositing shampoos: more readily absorbed through the skin, they increase the risk of exposure to unwanted substances.

Want to learn more? Feel free to download the May app, where you’ll find plenty of resources to support and guide you throughout your pregnancy.

Coloring your hair while pregnant: precautions to take

In general, it’s best to wait until the end of pregnancy before coloring your hair to avoid absorbing external products. However, if you feel that your color can’t wait, take the time to carefully check the product’s ingredients so that it is as natural as possible and certified organic by the International Nomenclature of Cosmetic Ingredients (INCI).

It is also essential to adopt safe practices for any hair coloring during pregnancy:

Before coloring:

• Choose gentle products: opt for plant-based dyes, natural henna (reddish brown or orange—definitely not black), or dyes without ammonia or parabens. These alternatives respect the hair fiber and limit the risk of scalp irritation.
• Do an allergy test: even if you’ve never had a reaction before, pregnancy can make the skin and scalp more reactive. Apply a small amount of dye behind the ear 48 hours before application.

During coloring:

• Ventilate the room: fumes from certain products, even ammonia-free ones, can be bothersome. Open windows and avoid confined spaces.
• Choose methods without direct contact: highlights, balayage, or partial bleaching are ideal because they don’t touch the scalp, thereby limiting chemical absorption.
• Favor methods that allow you to partially color the hair in targeted areas, without the product touching the skin.

After coloring:

• Rinse thoroughly: a long, careful rinse removes dye residue from the skin and hair.
• Moisturize your hair: use a gentle treatment to preserve shine and hair health.
• Monitor your skin: if you experience itching, redness, or allergic reactions, consult a healthcare professional promptly.

Note: even though plant-based dyes or pure henna are generally better tolerated, some so-called “natural” products hide synthetic additives to intensify shine or pigment longevity. It is therefore essential to check the ingredient list, as some blends may contain traces of ammonia or heavy metals.

Coloring your hair while pregnant: when should you consult a healthcare professional?

Certain situations require the advice of an experienced hairdresser or a healthcare professional:

• A history of allergies: if you’ve already had reactions to a dye, colorant, or hair products, ask a professional for advice before starting.
• A sensitive or damaged scalp: itching, irritation, or scalp injuries should be monitored closely during pregnancy.
• Skin conditions: if you have eczema, psoriasis, or other scalp conditions, a medical consultation is recommended before any coloring.
• Unusual reactions: if you notice unusual hair loss, red patches, or concerning symptoms after coloring, schedule an appointment promptly with a healthcare professional.

In summary, while coloring your hair during pregnancy is not formally contraindicated, it is still essential to choose your products carefully and take appropriate precautions to protect your health and your baby’s.

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Photo credits: LightFieldStudios | diignat | bernardbobo

This text was translated from French by an artificial intelligence. The information, advice, and sources it contains comply with French standards and may therefore not apply to your situation. Make sure to complement this reading by visiting the May US/UK app and consulting the healthcare professionals who are supporting you.