An honest answer, even though we sell keratin treatments.
Can you have a keratin treatment while pregnant?
Our advice is to wait until after pregnancy and breastfeeding. Formaldehyde-based treatments should be avoided completely, and even for formaldehyde-free formulas there are no clinical studies in pregnancy. Speak to your GP or midwife if you are unsure. Here is what we know, and how to manage frizz in the meantime.
By Yasmin, founder of Nero Hair · Updated 22 September 2026
The short answer
Our advice: wait until afterwards.
Formaldehyde-based keratin treatments should not be used during pregnancy. Formaldehyde is released as fumes when the treatment is heated with a flat iron, and it is a known carcinogen and respiratory irritant.
Formaldehyde-free treatments — including every treatment we sell — remove that main concern. But there are no clinical studies on any smoothing treatment during pregnancy or breastfeeding, so nobody can honestly promise they are risk-free.
Because a smoothing treatment is cosmetic and can wait, we recommend holding off until after pregnancy and breastfeeding. If you are considering one anyway, talk it through with your GP or midwife first.
Formaldehyde-based
Avoid
Formaldehyde-free
No studies yet
Our advice
Wait until after
Unsure?
Ask your midwife
Why formaldehyde matters
The main risk is fumes, not the product on your hair.
Older and cheaper keratin treatments release formaldehyde when heated. In a salon, that means breathing it in for the two to three hours the treatment takes — which is the main reason these treatments are not recommended in pregnancy.
Some products are labelled "formaldehyde-free" but contain ingredients that release formaldehyde when heated. If you are ever buying a smoothing treatment, check that it is both formaldehyde-free and aldehyde-free.
QIQI Hair Controller and Nanokeratin System are both formaldehyde-free and aldehyde-free, with no harmful fumes during application. That makes them a far better choice than formaldehyde-based treatments — but it does not replace medical advice during pregnancy.
Hair changes in pregnancy
Your hair may behave differently right now.
Hormone changes during pregnancy often make hair thicker, shinier or more textured — and some people find their curl pattern or frizz changes. After birth, many people notice more shedding for a few months.
That is another reason to wait: a treatment chosen for your pregnancy hair may not suit your hair a few months later. Once things have settled, you can pick the formula that matches your hair as it really is.
In the meantime
Gentle ways to manage frizz until then.
Switch to sulphate-free shampoo
Sulphates rough up the cuticle and make frizz worse. A gentle sulphate-free shampoo and conditioner make a noticeable difference.
Deep-condition once a week
A hydrating masque smooths the cuticle and tames frizz without any chemical smoothing.
Blow-dry downwards
Drying along the hair shaft, root to tip, flattens the cuticle for a smoother finish.
Finish with a light oil
A drop of finishing oil on the lengths seals the ends and adds shine.
Sleep on silk
Less friction overnight means less frizz in the morning.
What we recommend
Gentle, sulphate-free care for now.
Everyday sulphate-free shampoo, conditioner and a deep-conditioning masque to keep frizz down until you are ready for a treatment. If you have any concerns about a product, check the ingredients with your midwife.
From £18 · 75ml / 300ml / 1000ml
Smooth Service Shampoo
Sulfate-free keratin aftercare shampoo formulated to extend QIQI Hair Controller results. Deeply moisturising with 19 precision-selected ingredients. Prolongs smoothing treatment longevity by weeks. 95% felt nourished and smoother after one wash.
Shop now →
From £45 · 300ml
Hydration Fixation Conditioner
Sulfate-free keratin aftercare conditioner that detangles, hydrates, and locks in moisture. Extends the life of your QIQI Hair Controller treatment by weeks. 97% experienced hydrated, smoother hair after first use.
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From £24 · 75g / 250g / 350g / 1kg
Super Soaker Smoothing Masque
Deep-conditioning keratin aftercare masque for intense hydration between smoothing treatments. Extends QIQI Hair Controller results. Smooths, strengthens, and locks in shine. 98% reported healthier-looking hair after weekly use.
Shop now →Common questions
Keratin & pregnancy — FAQ
Can you have a keratin treatment while pregnant?
We recommend waiting until after pregnancy and breastfeeding. Formaldehyde-based keratin treatments should be avoided completely. Formaldehyde-free treatments remove the main concern, but there are no clinical studies on smoothing treatments during pregnancy, so speak to your GP or midwife if you are considering one.
Is formaldehyde-free keratin safe during pregnancy?
Formaldehyde-free treatments avoid the main known risk — breathing in formaldehyde fumes. However, no smoothing treatment has been clinically studied in pregnancy, so no one can guarantee it is risk-free. Our advice is to wait, or to get the go-ahead from your GP or midwife first.
Can you have a keratin treatment while breastfeeding?
The same caution applies. There is little research on smoothing treatments during breastfeeding. Many people choose to wait until they have finished; if you do not want to wait, check with your GP or health visitor first.
What if I had a keratin treatment before I knew I was pregnant?
Try not to worry — one treatment before you knew is very unlikely to be a cause for concern, especially if it was formaldehyde-free. Mention it to your midwife at your next appointment so they can reassure you.
How soon after giving birth can I have a keratin treatment?
Many people wait until they have finished breastfeeding, and until postpartum shedding has settled — often a few months. That way, you choose a formula that suits your hair as it is after pregnancy.
Free UK delivery over £80
Gentle care now. Smooth hair later.
Formaldehyde-free professional treatments and sulphate-free aftercare. Dispatched next working day. UK delivery 1–3 working days.