Is Sodium Hydroxide safe during pregnancy?
Chemical relaxers aren't expected to raise birth defect risk when used as directed, but NIH studies link frequent use to other health risks.
What the sources say
MotherToBaby notes older relaxers used sodium hydroxide (lye) and says hair treatments used as directed are not expected to greatly increase birth defect risk; scalp burns raise absorption. NIEHS Sister Study research linked frequent straightener/relaxer use with higher uterine and ovarian cancer risk and slightly lower fertility, without proving cause. Limit: space out treatments, protect the scalp, avoid on broken skin; consider waiting until after pregnancy. Breastfeeding: little reaches milk.
Also listed as
calcium hydroxide relaxer, chemical relaxer, chemical straightener, guanidine hydroxide, hair relaxer, lye relaxer, no-lye relaxer
Sources
- MotherToBaby: Hair Treatments
- NIH NIEHS: Cosmetics and Your Health: NIEHS Research Findings (fact sheet, Jan 2024)
Last reviewed . This is general information, not medical advice. Ask your doctor or midwife about your own situation.