The Long-Term Effects of Using Hair Straighteners on Your Hair Health

The popularity of hair straighteners reflects a global trend toward personal grooming and hair care, where styling tools play a pivotal role. With the hair straightener market set to grow from $591.2 million in 2018 to $861.1 million by 2026, it’s clear that these devices are more than just a passing trend. 

Unfortunately, many people are unaware of the dangerous side effects that some hair treatments have. 

In this article, let us explore the science behind hair straightening, as well as some of the dangers that exist. 

The Science Behind Hair Straightening

To understand how hair straighteners work, it’s essential to know a bit about hair’s natural composition. Hair straightening involves the application of heat to alter the natural structure of hair and break down the hydrogen bonds. 

These bonds hold the hair’s inherent shape, be it curly, wavy, or straight. When heat is applied, it temporarily disrupts these bonds, enabling the hair to be restyled into a straighter configuration.

Essentially, the science behind hair straightening is rooted in the manipulation of the hair’s hydrogen bonds through heat application. However, this manipulation can also happen chemically. 

Chemical hair straighteners work by breaking down the structural bonds in the hair and then resealing them into a straighter structure. 

The procedure usually entails using a chemical solution that modifies the hair’s proteins, especially the disulfide bonds that determine the hair’s inherent structure. This solution disrupts these bonds, permitting the hair to be reformed. 

After the solution has acted on the hair, a neutralizer is applied to re-form the bonds in their new, straightened alignment. This treatment can significantly alter the hair’s texture and is usually permanent, meaning the treated hair will remain straight until new hair grows.

However, are these methods safe? Are there any dangers to subjecting one’s hair to long-term changes? What does the research say? Well, let’s find out. 

The Long-Term Risks of Hair Straighteners

We know that chemical treatments lead to significant changes at the molecular level in the hair. The core of your hair’s structure is a protein known as “keratin.” Exposure to high heat from hair straighteners can fundamentally change the shape of keratin strands. When subjected to temperatures over 300°F, ⍺-keratin in hair transforms into β-keratin. 

This conversion weakens the hair, leading to a loss of elasticity and increased susceptibility to damage. 

Unfortunately, the side effects go beyond the weakening of the hair. The relationship between the use of hair straighteners and the risk of cancer, particularly uterine cancer, is concerning.

Research by the US National Institutes of Health (NIH) indicates that chemical hair straighteners and relaxers increase the likelihood of uterine cancer in women. 

The research involved data from over 33,000 women and aimed to identify risk factors for breast cancer and other health conditions. It found that women who reported using hair straightening products were nearly twice as likely to develop uterine cancer.  

Moreover, frequent users of hair straighteners (more than four times in the previous year) had about 2.5 times the risk of developing uterine cancer​.

These studies have also had real-world consequences, as several hair straightener cancer lawsuit cases were filed by those affected. As of October 2023, a total of 6,027 hair straightener cancer lawsuits had been filed. 5,996 of these cases are still pending in the Illinois Multidistrict Litigation.

According to TorHoerman Law, companies facing litigation include L’Oreal, African Pride, and Dark & Lovely, among others. 

What Safe Alternatives Exist?

Considering the health risks that exist, it is well worth looking into safe, straightening treatments. Thankfully, there are a number of options available. Let’s take a look at three. 

1. Keratin Treatments

These treatments involve applying a keratin-based formula to the hair, which is then sealed in with a flat iron. The process smoothens the hair cuticle, resulting in straighter, frizz-free hair. 

While keratin treatments often involve heat application, they are generally considered safer than traditional chemical relaxers. However, it’s crucial to ensure that the product is formaldehyde-free, as formaldehyde can pose health risks.

2. Hair Straightening Brushes

Hair straightening brushes detangle and straighten hair simultaneously at a lower heat setting than traditional flat irons. As a result, they are gentler and distribute heat more evenly across the hair, reducing the risk of heat damage.

3. Silk Press

A silk press is a modern version of the traditional press and curl. It involves using a blow dryer and then a flat iron to achieve a straight look. The key to a silk press is using a heat protectant and not using excessively high temperatures. 

Hair straightened by a silk press can last anywhere from 2 to 5 weeks, depending on hair maintenance. To prolong the results, it’s advisable to avoid humidity, water, or steam, as these elements can revert the hair back to its natural texture.


Hair straighteners are a popular tool for achieving various hairstyles, however, their long-term use poses significant risks to hair health. Understanding the science behind hair straightening, its physical and chemical impacts on hair, and adopting protective measures can help mitigate these risks. 

Thoughtful and informed use of hair straighteners, coupled with regular hair care practices, can ensure the well-being of your hair in the long term. 

With so many studies coming out on the dangers of chemical hair straighteners, it makes sense to be extra careful.