Is keratin treatment safe while pregnant?

What do health bodies say about keratin treatments in pregnancy?

No body we found has published a rule on getting a keratin treatment as a client while pregnant. What is published is about the formaldehyde these treatments can release, and mostly about the people who give them.

Health bodies call these hair smoothing or straightening treatments. The FDA says the products often contain formaldehyde. On a label it can also be called formalin or methylene glycol.

MotherToBaby has a fact sheet on hair treatments in pregnancy. It says smoothing treatments can raise formaldehyde levels for people who provide them, most of all in workplaces with higher levels.

Some studies of people who work around formaldehyde have suggested a higher chance of miscarriage, MotherToBaby says. Those were studies of people at work.

On birth defects, MotherToBaby says getting or providing hair treatments as directed is not expected to greatly increase the chance.

The CDC’s workplace health institute, NIOSH, has a page on formaldehyde and reproductive health. It says current exposure limits were written for healthy non-pregnant workers and might not protect a developing fetus.

How does a keratin treatment release formaldehyde?

Heat releases it. The FDA says that when the smoothing solution is heated, the formaldehyde in it goes into the air as a gas.

OSHA, the US workplace safety agency, says some products hold chemicals that release formaldehyde when heated. It names flat ironing and blow drying as examples.

The FDA says that if the salon is not properly ventilated, both stylists and their clients are at risk of breathing it in. Its warning covers the client as well as the stylist.

OSHA reports one salon where formaldehyde during blow drying measured five times its short term limit. NIOSH found formaldehyde at lower levels near the next stylist and around the salon, OSHA reports. Workers other than the stylist could be exposed.

No body cited here gives a measured level for a client during one appointment. The FDA lists reactions people have reported, such as headaches and dizziness, eye irritation, sore throat, cough, wheezing, nausea, chest pain, vomiting and rash.

Can a formaldehyde free keratin treatment still contain formaldehyde?

Yes. OSHA says products that do not list formaldehyde, or that claim to be formaldehyde free, can still expose salon workers to it.

OSHA reports a test by NIOSH. A smoothing solution labelled Formaldehyde Free contained 11% formaldehyde. Air tests in salons using it found levels above OSHA’s limits.

OSHA also says many smoothing products contain formaldehyde or formaldehyde dissolved in water. So the words on the front of the bottle may not tell you what is inside.

No body cited here says whether a formaldehyde free keratin product is safe in pregnancy.

Is a keratin treatment safe in pregnancy, while breastfeeding, trying to conceive, or with PCOS?

MotherToBaby is the one source cited here that covers hair treatments in pregnancy, breastfeeding and getting pregnant. Its lines are findings, not a rule for keratin clients.

The chip on each row is what the Truva app shows for formaldehyde at that stage.

Pregnancy

AVOID MotherToBaby says hair treatments used as directed are not expected to greatly increase the chance of birth defects. Its miscarriage findings come from people at work. The CDC says exposure limits, written for non-pregnant workers, might not protect a developing fetus. No body we found has a rule for clients. See the app’s pregnancy ingredient list.

Breastfeeding

AVOID MotherToBaby says that on healthy, unbroken skin, large amounts of hair care chemicals are unlikely to get into breast milk. That line is about hair care chemicals through the skin. See the breastfeeding ingredient list.

Postpartum, not breastfeeding

AVOID The sources cited here give no rule on keratin treatments postpartum while not breastfeeding. The FDA’s warning about heat and ventilation is written for stylists and clients alike.

Trying to conceive

AVOID MotherToBaby reports on 19 studies of hairdressers and cosmetologists. They found a small increase in the time it took to get pregnant. Two later studies suggested hair care products might be linked to trouble getting pregnant. One looked at hair straighteners. The app’s flag here is its own call about the weeks before a pregnancy is known.

PCOS

AVOID The sources cited here give no rule on keratin treatments with PCOS. If you could get pregnant, the trying to conceive row is worth reading too. The app has a PCOS ingredient list.

Not pregnant or breastfeeding

AVOID The FDA’s warning is for everyone in the salon. Without proper ventilation, stylists and clients are at risk of inhaling formaldehyde. Its list of reported reactions includes headaches, cough and rash.

What should I look for on the label, at a salon or at home?

Look for three words the FDA names: formaldehyde, formalin and methylene glycol.

Methylene glycol is formaldehyde dissolved in water, OSHA says. The app has pages for formaldehyde and methylene glycol.

A salon product may have no list to read. The FDA says products sold only to salon professionals may not have a list of ingredients. The US labelling law the FDA names covers only products sold to consumers.

A kit sold to you as a consumer falls under that law, so check its list for the three words. A formaldehyde free claim can still be wrong, as the NIOSH test showed.

For people who work with hair products, MotherToBaby says well ventilated areas and recommended safety practices help reduce exposure.

Who should I ask about a keratin treatment in pregnancy?

Ask your midwife or doctor, and ask the salon for the product’s name and ingredients. That is our suggestion, not a published rule.

Tell them whether the treatment is sealed with a flat iron or a blow dryer, and how well the room is aired. Heat and ventilation are the two things the FDA and OSHA tie to breathing formaldehyde in.

If your hair question is about hair loss instead, we read what is published on minoxidil in pregnancy and breastfeeding.

Where this came from

Every health claim on this page links to the body that published it. Nothing here comes from another blog.

Every link above was fetched and confirmed to resolve on 6 September 2026.

Truva summarises published guidance from bodies including ACOG, the FDA, the EU SCCS and the Cosmetic Ingredient Review. It has no access to your medical history and it is not a substitute for your doctor, dermatologist or midwife. This post was written by the Truva team from the sources listed above. It has not been reviewed by a clinician, and nothing in it is a diagnosis or a prescription. If you are pregnant, breastfeeding or being treated for PCOS, take the ingredient list to the person looking after you.