Recent Blog Articles
Masks save lives: Here’s what you need to know
Stretching studios: Do you need what they offer?
Why are women more likely to develop Alzheimer’s disease?
Seeing red? 4 steps to try before responding
Tics and TikTok: Can social media trigger illness?
Pandemic challenges may affect babies — possibly in long-lasting ways
4 immune-boosting strategies that count right now
If you have knee pain, telehealth may help
How to address opposition in young children
New study investigates treatment-associated regrets in prostate cancer
Ask the doctor: Is hair straightening safe?
Q. I had my hair straightened six months ago. Is there any danger in getting these treatments twice a year? I hear they may contain formalin or formaldehyde.
A. Like permanent wave solutions, hair straightening products are designed to break and reform the chemical bonds in keratin, the key structural protein in hair and nails. Permanent wave solutions make the hair more curly; hair straighteners, as the name implies, make it very straight.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
Free Healthbeat Signup
Get the latest in health news delivered to your inbox!