13/10/2025
By Althea Gooden, Certified Trichologist & Wellness Coach
Learn the truth about chemical hair relaxers and their possible link to uterine and breast cancer. Certified Trichologist Althea Gooden explains ingredients, research, and safer alternatives for scalp and hair health.
What’s in a Hair Relaxer?
Hair relaxers chemically break the natural disulfide bonds in the hair to make it straight.
There are three common types:
1. Lye Relaxers (Sodium Hydroxide): Strong, high-pH formulations that alter the hair’s internal structure.
2. No-Lye Relaxers (Calcium Hydroxide or Guanidine Carbonate): Gentler, but can cause scalp dryness and calcium buildup.
3. Thio-Based Relaxers (Ammonium Thioglycolate): Milder options that still alter the hair shaft’s natural pattern.
Each product may also include preservatives, fragrances, stabilizers, and conditioning agents, some of which can pose health risks.
⚠️ Ingredients of Concern
Research has identified several ingredients commonly found in hair relaxers that may be linked to hormone disruption or cancer:
• Formaldehyde & Formaldehyde-Releasing Agents (DMDM Hydantoin): Classified carcinogens often found in straightening and smoothing treatments.
• Phthalates: Hidden under “fragrance,” these chemicals can interfere with hormone balance.
• Parabens: Mimic estrogen in the body and are found in some cancer tissues.
• Diethanolamine (DEA) & Triethanolamine (TEA): Can form harmful nitrosamines when mixed with certain preservatives.
• Phenol, Toluene & Resorcinol: Common irritants and potential carcinogens.
When these ingredients touch the scalp particularly if the skin is irritated or burned they can be absorbed directly into the bloodstream.
🩺 What Research Reveals
In 2022, a study from the U.S. National Institutes of Health (NIH) reported that women who used chemical hair relaxers four or more times per year had a higher risk of uterine cancer than those who never used them.
Other studies also suggest potential links to breast and ovarian cancers.
The risk increases with frequency and duration of exposure especially for women who began relaxing their hair at a young age or used these products over many years.
⏱️ How Often Is Too Often?
Frequent use such as every 6–8 weeks raises concern because:
• It increases scalp exposure to harsh chemicals.
• Relaxers are often applied to already-processed hair, amplifying scalp irritation.
• Inhalation of chemical fumes adds to systemic exposure.
Occasional use (3-4 times year) may pose a lower risk, but awareness and moderation remain key.
Healthier Alternatives for Straighter Styles
You can still achieve smooth, manageable hair without compromising health:
• Herbal and Ayurvedic Treatments: Cassia, amla, and fenugreek naturally smooth and strengthen strands.
• Formaldehyde-Free Texture Release Systems: Choose certified clean formulations only.
• Heat Styling with Protection: Use plant-based thermal shields to minimize heat damage.
• Protective Styles: Braids, twists, and silk presses maintain style and scalp balance.
💬 Professional Advice from a Trichologist
If you or your clients use relaxers:
• Avoid applying to irritated or inflamed scalp.
• Limit to no more than three times per year.
• Always follow with neutralizing and deep-conditioning treatments.
• Periodically detox the scalp and support internal health with antioxidants and balanced nutrition (vitamins A, C, E, zinc, and omega-3s).
Final Thoughts
Your scalp is living tissue — it breathes, absorbs, and reacts. What you put on it matters. By understanding your hair products and making informed choices, you protect not just your crown but your overall well-being.
For holistic scalp restoration or personalized trichology consultations, visit The Salon Scalp Clinic.
And to continue your healthy hair journey, read my e-book:
📘 The Hair and Scalp Health Do’s and Don’ts: Essential Tips for Lifelong Vibrancy — available now on Amazon.
Althea Gooden 