Is Hair Dye Safe During Pregnancy?
Published June 29, 2026 | By SafeMama Editorial Team | Editorial policy
The short answer: Per the NHS, hair dye is considered low-risk in pregnancy because only small amounts of dye chemicals are absorbed through the scalp. Many salons and providers nonetheless suggest waiting until the second trimester as a precautionary default, and choosing highlights/balayage over all-over root colour.
What the NHS actually says
"Most research, although limited, shows it's safe to colour your hair while pregnant. Some studies have found that very high doses of the chemicals in hair dyes may cause harm, but they don't reflect the small amount of chemicals you're exposed to when colouring your hair."
Many people choose to wait until after the first trimester anyway, when major organ development is complete.
Lowering the (already low) risk further
- Wait until the second trimester — a precautionary default many providers suggest
- Choose highlights, balayage or ombré — the dye doesn't touch the scalp, so there's minimal absorption
- Use ammonia-free or "demi-permanent" colour — fewer harsh chemicals, gentler smell
- Ensure good ventilation — open windows or a salon with good air flow
- Don't leave dye on longer than the box instructs
- Rinse thoroughly
- Wear gloves if you're applying it yourself
Henna in pregnancy
- Pure natural henna (Lawsonia inermis) — the red-orange dye — is generally considered safe in pregnancy
- "Black henna" — AVOID. It contains added para-phenylenediamine (PPD), which can cause severe skin reactions, contact dermatitis and lifelong sensitivity. The same caution applies for "black henna" temporary tattoos.
- "Henna" boxed dyes that include synthetic colourants behave like regular dye; check the label
Other hair treatments
| Treatment | Pregnancy status |
|---|---|
| Brazilian / keratin blowout (formaldehyde-based) | Avoid — formaldehyde fumes |
| Formaldehyde-free smoothing | Read the label carefully; many "free-from" claims aren't |
| Hair relaxers | Limited safety data — many providers advise pausing |
| Perms | Limited data; the smell alone can worsen pregnancy nausea |
| Bleach (root or all-over) | Same low-risk profile as dye; same precautions |
| Toner / glaze | Low-risk |
| Haircuts / treatments / Olaplex | Safe |
If you're doing your own colour at home
- Open a window or run an extraction fan
- Use gloves
- Don't leave dye on longer than instructed
- Do a patch test first (especially if you've had reactions before — pregnancy can change skin sensitivity)
- Skip if you have pregnancy nausea — strong smells can trigger it
When to skip dye entirely
- Severe morning sickness — the smell will not help
- Active scalp conditions (eczema, psoriasis, cuts) — absorption is higher through broken skin
- If your provider has specifically advised against it
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