Can I Get Chemical Hair Straightening While Pregnant?

Woman with chemically straightened hair

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It’s an unfortunate fact of many of our lives: We often want what we can’t have. And while the “straight” grasses of hair may look greener—or more desirable—from the other side for some, the opposite can be true for others. Some people with straight hair may envy bouncy, luscious waves or curls, while there are those with a lot of body who would rather have straight hair. If you're in the latter camp, you may be curious about chemically straightening your hair. 

For most of adulthood, the decision to chemically straighten your hair is a personal stylistic one. But when you’re pregnant, you must take your developing baby’s health and needs into account too. To find out if it’s safe to chemically straighten your hair while pregnant, we tapped two doctors to share their insights. Ahead, learn all you need to know about chemically straightening your hair while pregnant—including why you may want to hold off on making that appointment.

Chemical Hair Straightening During Pregnancy

Sure, anyone can straighten their hair using devices like a blow dryer or flat iron. But, while those methods can be effective, they’re also only temporary—washing right out during your next shampoo. “Permanently” chemically straightening your hair takes it a step further, allowing you to retain your sleek strands for a few months until your new, natural roots grow in.

“Chemically straightening your hair works by breaking the bonds between keratin fibers and forming new bonds between the keratin,” explains Rachel Nazarian, MD, FAAD, board-certified dermatologist at Schweiger Dermatology Group in NYC. This process physically changes the structure of your hair, thereby relaxing or straightening it. Most commonly, these strengthening techniques are referred to as “keratin treatments," "Brazilian blowouts,” "Japanese hair straightening," or "thermal reconditioning."

“In brief, hair is chemically straightened by applying ingredients that break the protein bonds that create curls,” summarizes Blair Murphy-Rose, MD, FAAD, a board-certified dermatologist at the Laser & Skin Surgery of New York in NYC. “Once these disulfide bonds have been broken, the hairs become straight.” Basically, if you remove your curls’ support, you no longer have curls—at least until new hair grows in, that is.

Every pregnancy is different. Be sure to consult with a healthcare provider about your circumstances if you have any questions about chemically straightening your hair while pregnant.

Is It Safe for Baby?

Whatever kind of chemical hair straightener you prefer, one thing remains clear: chemical hair straightening involves, well, chemicals. “It is wise and safest to avoid [chemical hair straightening] while pregnant,” cautions Dr. Murphy-Rose. 

Regulatory speaking, there are sufficient concerns about the chemicals used in straightening products. This is because healthy, bouncy curls tend not to go down without a fight. Therefore, the chemicals used are generally harsh and contain safety risks for both you and your baby.

Why You Should Not Get Chemical Hair Straightening While Pregnant

Acknowledging that chemical hair straightening is a controversial topic, Dr. Nazarian says she is not one to recommend it for pregnant people.

“Most hair straightening involves the use of formaldehyde and is often discouraged during pregnancy,” says Dr. Nazarian. “Because there are a limited number of clinical trials in pregnancy, and we know that chemicals may be absorbed through your scalp during these treatments, there’s always potential for fetal absorption, and most physicians will recommend the fewer chemicals you use in pregnancy, the better.” Moreover, you'll likely be sitting for more than an hour while getting your hair straightened, inhaling all those potentially harmful fumes all the while.

Just hearing which chemicals are commonly used during hair straightening may be enough to give you pause: Along with formaldehyde (yep, the ingredient used in human embalming fluid), hair straightening chemicals include cyclosiloxanes, parabens, sodium hydroxide, diethanolamine, phthalates, benzophenone-3, and triclosan. All of these chemicals are potential human health and environmental hazards that can disrupt your endocrine system (proper functioning of which is key to a healthy pregnancy), respiratory system, or skin barrier. They may also harm fetal development.

Risks of Chemical Hair Straightening While Pregnant

We should note: Our intention is never to scare you away from any beauty treatment—especially if you’re a super fan. We simply seek to give you accurate information, so you can make your own informed decision for you and your baby. Here is what research has to say about the potential health impacts of chemicals commonly used in hair straightening.

Endocrine Disruption and Asthma Aggravation

A recent study by the California Department of Toxic Substances and Control on three hair relaxers (straightening products) found 35 endocrine-disrupting and asthma-provoking chemicals. The former is especially concerning as negative impacts to your endocrine system while pregnant can disrupt vitamin D levels as well as sex and thyroid hormones in you and your baby. This can result in premature birth, preeclampsia, trouble with blood sugar levels, infant cryptorchidism (failure for testes to descend) and hypospadias (misplacement of the urethra), and lasting development issues that persist into babyhood and childhood.

Birth Defects

When you're pregnant, your baby’s health and safety are, of course, top of mind. That's why it's important to avoid certain things that may be associated with birth defects. “Some of the chemicals used in hair straightening may be absorbed through the scalp or inhaled, and could potentially induce teratogenic [a.k.a. fetal-development-harming] effects, warns Dr. Murphy-Rose.

Scalp Irritation 

Whether or not you’re pregnant, continually applying harsh chemicals to your head can make scalp disorders worse. For instance, chemicals will do your postpartum itchy scalp no favors. Plus, any damage your scalp incurs is likely to make it more susceptible to further irritation or damage.

When Can I Resume Chemical Hair Straightening?

This one is pretty straightforward: When in doubt, wait it out. “While there is not sufficient data to be certain, it is generally considered safe to resume chemically straightening your hair after delivery,” says Dr. Murphy-Rose. However, always be sure to run anything that has even a remote chance of harming you or your newborn by your healthcare provider to be sure. 

“Remember, the fewer chemicals absorbed through your body, the better,” Dr. Nazarian recommends. “It’s safer to wait until after you’ve given birth to resume these beauty habits.”

Pregnancy-Safe Alternatives 

Even in beauty, anytime a door closes, a window opens. Although it may not be advisable to chemically straighten your hair while pregnant, there are safe, satisfying haircare options you may try (and love).

Dr. Nazarian recommends henna (or veggie dyes), which can have a straightening effect and are less dangerous and unlikely to harm your baby. On the other hand, you can always go back to basics. Dr. Murphy-Rose advises simply using a straightening iron. Despite it not lasting as long, at least you’ll have peace of mind that you and your baby won’t be harmed by it. Just be sure to keep it a few inches from your facial skin and scalp to avoid any burns. 

A Word From Verywell

While it can be inconvenient to give up on some luxuries in life when you’re pregnant, your baby's health is priceless. It's best to avoid chemical hair straightening during pregnancy due to some potentially serious risks to you and your baby, but there are safe, tried-and-true haircare alternatives that can make you look and feel great. When in doubt, always talk to your healthcare provider about any concerns you may have while pregnant.

3 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. California Department of Toxic Substances and Control. Chemicals in Hair Straightening  Products Background Document.

  2. Tal R, Taylor HS. Endocrinology of Pregnancy. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext., Inc.; 2000.

  3. Frontiers in Public Health. The Endocrine Disruption of Prenatal Phthalate Exposure in Mother and Offspring.

By Cat Matta
Cat is a linguistic alchemist and expert wordsmith who has written and edited for some of the world's biggest brands. However, she particularly enjoys the medical, aesthetic, pharma, mental health, and beauty realms. She works full-time as a senior content manager at a multinational digital agency.