In this post
Yes, you can dye your hair while pregnant. The NHS page on using hair dye in pregnancy says “most research shows that it’s safe to dye or colour your hair while pregnant”, because you’re “only exposed to very low amounts” of the chemicals involved. ACOG agrees: “Most experts think that using hair dye during pregnancy is not toxic for your fetus.” The NHS adds a short list of ways to cut the exposure further: gloves, the minimum time, an open window and a thorough rinse.
Where this post stops
I’m pregnant with my second and my roots became a visible problem at about week nine. I’m not a doctor, a midwife or a colorist. This post is what three health sources say about coloring your hair, and how to do it the careful way. It doesn’t recommend a brand of dye. If you have a scalp condition or a history of reacting to color, ask your OB or midwife before you start.
Why the answer is yes
All three sources make the same two points.
The dose is tiny. The NHS says the chemicals in permanent and semi-permanent dyes “may cause harm, this is only in very high doses.” ACOG’s Ask ACOG answer on hair dye says animal studies show “high doses of these chemicals do not cause serious birth defects.”
Very little gets in. ACOG says “only a small amount of chemicals from hair dye is absorbed through the scalp.” The NHS says your scalp “doesn’t absorb much of the hair dye, especially if you have a healthy scalp.” MotherToBaby’s fact sheet on hair treatments says that when products are used as directed, the amount absorbed “by unbroken, healthy skin of the scalp is small.”
A healthy, unbroken scalp comes up in all three. If yours is scratched, sore or flaring, wait for it to heal or ask your provider first.
Should you wait until after the first trimester?
This line shows up on every blog, usually with no source. The NHS is where it comes from, and it words it as a choice: “You might decide to wait until after the first 12 weeks of pregnancy to dye your hair, when the risk of chemical substances harming the baby is lower.”
So it’s “you might decide to”, and it isn’t a must. ACOG’s answer doesn’t mention a waiting period at all. I waited, mostly because in the first trimester the smell of anything stronger than toast sent me out of the room, and two hours in a salon chair was beyond me. If waiting makes you feel better, wait. If you colored your hair at week six before you’d read any of this, the sources above all say the exposure is very low.
How to dye your hair the careful way
The NHS gives a home-coloring list, and it’s worth following exactly. If you’re doing it yourself, “always”:
- Wear gloves, “as skin can be more easily irritated while you’re pregnant.” Box-dye gloves tend to be thin and loose. A pair of proper nitrile ones, like MedPride nitrile gloves, fits better and won’t tear at the wrist.
- Use the minimum time. “Leave the dye on for the minimum time – check the manufacturers advice and do not exceed the maximum application time.” Set a timer on your phone, because pregnancy brain will lose track of it for you.
- Open a window. “Apply hair dye in a well-ventilated room to minimise contact with any fumes.” A bathroom with the door shut and no fan doesn’t count. MotherToBaby adds that “a strong smell does not mean that you have a high level of exposure”. The reverse holds as well, so ventilate even if the dye barely smells.
- Rinse well. “Rinse your scalp thoroughly with water and wipe away any excess dye.”
Two more steps come first, and they apply even to a shade you’ve used for years:
- Do a strand test. The NHS says to “always do a strand test first”, because “your hair may react differently during pregnancy.”
- At a salon, say you’re pregnant. The NHS says to “tell them you are pregnant and ask for a patch test, even if it’s a dye that they’ve used on your hair previously.”
The gloves-and-open-window approach is the same one I used for the nursery walls. That job is covered in can you paint while pregnant.
Highlights, henna and the lower-contact options
The NHS points to two ways to cut contact further.
Highlights. “Highlighting your hair, by putting the dye only on to strands of hair, reduces any risk. The chemicals used are only absorbed by your hair, and not by your scalp or bloodstream.” MotherToBaby makes the same point about highlights, lowlights, frosting and streaking, which put color on “the hair shaft without touching the skin.”
Vegetable dye. The NHS suggests “a safer alternative such as a semi-permanent pure vegetable dye, like henna.” The word that matters there is “pure”, so read the ingredient list. MotherToBaby notes that hair treatments are regulated as cosmetics and “do not need FDA approval before they go to the market”, and that products made outside the United States “might contain dangerous substances or contaminants, such as heavy metals.”
Bleach, perms and relaxers
The NHS page is about dye only. MotherToBaby’s fact sheet is the one I loaded that covers the rest. It groups “coloring, curling (permanents), bleaching, and straightening (relaxers)” together and concludes: “Getting or providing hair treatments as directed is not expected to greatly increase the chance of birth defects.”
It adds one caution. “Some hair straightening and smoothing treatments can contain formaldehyde or chemicals that release formaldehyde when heated”, and it notes that some studies of people who work around formaldehyde “have suggested an increased chance of miscarriage.” Those studies are about workplace exposure, where the levels are higher than one appointment. If you’re booking a smoothing treatment, ask the salon what’s in it, and ask your OB.
If you work as a hairdresser, MotherToBaby has a section for you: a well-ventilated space, protective gloves, washing your hands after handling products, frequent breaks, and not eating or drinking at your station.
When to call your OB or midwife
Nothing in this post is an emergency, but these are worth a call or a question at your next visit:
- Your scalp or skin reacts. That includes itching, burning, swelling or a rash during or after coloring. Rinse the dye off and call.
- You feel faint, sick or headachy from the fumes. Get into fresh air first. If it doesn’t pass, call.
- You have a scalp condition and want to color anyway.
- You’re worried. The NHS’s own last line is: “If you’re unsure or worried about the potential risks associated with dyeing your hair while pregnant, speak to your midwife or doctor.”
FAQ
Is box dye or salon dye safer when pregnant?
None of the three sources ranks one above the other. The NHS gives rules for both: gloves, minimum time, ventilation and a rinse at home, and a patch test and a heads-up at the salon.
Can I bleach my hair while pregnant?
MotherToBaby includes bleaching in the hair treatments that, used as directed, are “not expected to greatly increase the chance of birth defects.” Highlights that keep bleach off the scalp are the lower-contact route.
Why did my usual color come out different?
The NHS says pregnancy “can affect your hair’s normal condition”, so “your hair may react differently to colouring than it usually does.” That’s why it tells you to do a strand test every time.
Is it safe to dye my hair while breastfeeding?
MotherToBaby says that, used as directed on healthy skin, “it is unlikely that large amounts of hair care chemicals would get into breast milk.”