Are Keratin Treatments Safe During Pregnancy?

Keratin, a protein that makes up the outer surface of hair, can break down or get damaged, the Cleveland Clinic says. A keratin treatment is a chemical process that can work to restore the hair’s outer surface, resulting in smoother, shinier hair.

If you’re pregnant, consider the risk of exposure to chemicals from such treatments, says MotherToBaby, a health information service that produces scientific research on pregnancy. These treatments typically contain chemicals that may be harmful, including formaldehyde, which has been linked to an increased chance of miscarriage among women who work around it. Always talk to your doctor if you’re concerned about chemical exposure during pregnancy.

Keratin is a protein found in the hair, nails, and skin, according to the Cleveland Clinic. It affects your hair texture and whether it is straight, wavy, or curly, according to the National Center for Health Research, an independent nonprofit that conducts and analyzes health research. During a keratin treatment, a topical solution containing formaldehyde, or methylene glycol (a chemical that releases formaldehyde during the treatment process) is applied to the hair, left to set, then blown dry and flat-ironed. The combination of formaldehyde, heat, and compression causes the keratin in the solution to bind to the keratin in the hair, making the hair smoother and straighter.

Keratin treatments make hair look healthier, so they’re often thought to be better for your hair than dyes or perms. But because the treatments are likely to expose you to harmful chemicals like formaldehyde, which can be inhaled or absorbed through the skin, they may have an effect on your unborn child. Formaldehyde is also classified as a human carcinogen, meaning that exposure to it has been linked to cancer, says the U.S. Food and Drug Administration (FDA).

Most hair stylists will advise you to forego keratin treatments until after you’ve given birth and also finished nursing. Keratin treatments are relatively new, research says, and there’s no specific proof that they won’t harm your child, according to the UK Teratology Information Service, which provides information on exposure risks during pregnancy.

Keratin treatments containing formaldehyde and chemicals that release it could compromise your health, and specific risks to the health of your fetus can’t be ruled out, the UK Teratology Information Service says. While salons also don’t generally recommend formaldehyde-free keratin treatments for pregnant women, any formulas with formaldehyde are a definite no-no, the Cleveland Clinic says.

Exposure to formaldehyde can cause acute eye, lung, throat, and skin irritation or lead to cancer, so whether you’re expecting or not, it may be wise to avoid it. Ask your stylist for the specific ingredients in any treatments you get, so you know exactly what is being applied to your hair.

The FDA had previously proposed a federal rule to ban hair smoothing and straightening treatments containing formaldehyde and formaldehyde-releasing chemicals, due to their adverse effects on health; a decision had been pending. According to NBC News, a January 2025 White House executive order pausing all federal regulations means the future of the proposed ban is uncertain.

At-home hair treatments may seem safer, but it’s important to check the ingredient list of any product you use, the FDA says. Formaldehyde and chemicals that release it can cause adverse health effects in anyone, not just women who are pregnant.

Some at-home keratin kits have been known to contain formaldehyde-releasing chemicals, which are classified as carcinogens, according to research. They’re also known to sensitize skin, leading to allergic reactions. They can cause complications such as skin, eye, nose, throat, and lung irritation as well. While pregnant, avoid any type of at-home treatment that contains formaldehyde or formaldehyde-releasing chemicals, including:

• Quaternium-15
• DMDM hydantoin
• Imidazolidinyl urea
• Diazolidinyl urea
• Polyoxymethylene urea
• Sodium hydroxymethylglycinate
• Bromopol
• Glyoxal