What you may have heard
Chemical hair products used to straighten curly or wavy hair may increase your risk of hormone-related cancers.
What the science tells us
Chemical hair straighteners, also called hair relaxers, have been linked to uterine and ovarian cancers, with exposure greatest among Black women. These products may contain endocrine disrupting chemicals that mimic estrogen and interfere with the body’s hormone balance. Absorption of these chemicals through the scalp raises concerns about long-term cancer risk.
Epidemiological Evidence
Data from the Sister Study also suggests that frequent use of hair straighteners is associated with an increased risk of ovarian cancer (White et al.). Some studies have explored a potential link to breast cancer as well, though findings are less consistent.
Laboratory Evidence/Supporting Evidence
Many scientists are concerned about the risks of formaldehyde, also known as formalin and methylene glycol, found in some chemical hair products. Formaldehyde is an IARC-classified carcinogen and poses health risks when inhaled or in contact with eyes or skin (FDA). The Food and Drug Administration is currently working to ban formaldehyde from chemical hair straighteners and other consumer products. Additional chemicals of concern include parabens, phthalates, and certain metals, which may also function as endocrine disruptors.
How to reduce your risk
- Limit the use of chemical hair straightening products, especially those containing formaldehyde.
- Engage in regular physical activity and follow a balanced, nutritious diet. Obesity is a significant risk factor for hormone-related cancers.
Bottom line
Some studies suggest a link between chemical hair straighteners and hormone-related cancers; however, causation has not yet been established. Researchers recommend further studies to better understand this relationship. If you are concerned about potential cancer risk, consider reducing use of chemical hair straighteners and maintaining a healthy lifestyle to support overall cancer prevention.