Are Sulfates Bad for Your Hair? The Case Against Sulfates in Shampoo

If you want to take better care of your hair and the planet, sulfate-free shampoo is the way to go.

You’ve read all about it and your hairstylist keeps telling you: sulfates are bad for your hair. But are they really that bad?

The short answer is yes, sulfates are not only hard on your hair and your body, but they are hard on the planet, too. If you’re looking to practice better self-care this year while also living a more sustainable life, here’s everything you need to know about sulfate-free products and why they are the better choice.

What Are Sulfates? (And Why Are They in Our Shampoo?)

So what are sulfates, anyway? And why are they used in personal-care products like shampoo and body wash?

Sulfates are surfactants, compounds that effectively reduce surface tension between two liquids or a liquid and a solid. Surfactants also act as detergents, wetting agents, emulsifiers, foaming agents and dispersants.

In the case of sulfate-containing shampoo, the job of these ingredients is to lower the surface tension between your shampoo and skin, making the shampoo more effective at cleaning dirt, oil and dead skin from your hair and scalp.

Most brands of shampoo contain at least one of these common forms of sulfates, sodium lauryl sulfate, sodium laureth sulfate and ammonium laureth sulfate, often abbreviated as SLS, SLES and ALS, respectively. These chemicals provide that foamy lather we associate with getting clean. The effect may be visually satisfying, but the inclusion of sodium lauryl sulfate, sodium laureth sulfate, sodium laureth sulfate, and ammonium laureth sulfate doesn’t actually do anything to make your hair cleaner.

We put this substance in our hair without a second thought, but did you know it is also a key ingredient in powerful cleaning products like dish liquid and laundry detergent? Sulfates can be a little excessive, and for some people they are downright uncomfortable. There’s a reason why the CDC advises people to be careful of overexposure to the chemical.

Why Are Sulfates Bad for Your Hair (and Body)?

When it comes to products, too much power can be bad. For example, has anyone ever told you that using shampoo every day is bad for your hair?

This colloquial wisdom exists because both consumers and hairdressers have claimed that shampoo with sulfates is unnecessarily strong and can gradually erode hair, leaving it dry and brittle. Professionals in the bathroom products manufacturing industry have supported this allegation.

“Sulfate can harm the hair if the balance of the formula is not just right, and shampoo with SLS as an ingredient will definitely do some damage to the scalp and the sebaceous glands,” said Andy Stafford, Technical Manager at Vanguard Soap.

You may have heard rumors that sodium lauryl sulfate can cause cancer, but existing scientific evidence suggests that this claim is false. Still, research has also shown that sulfate shampoo can also have adverse effects on your hair and scalp.

Sulfate Removes Hair Proteins and Natural Oils

Your hair is primarily made of protein, with a variety of nutrients also included in the mix. To be exact, protein constitutes for around 91% of each hair fiber. When these proteins are damaged, it can make your hair weaker in both appearance and strength, leading to split ends and breakage.

A study published in 2005 concluded that sulfates could lead to the deterioration of hair protein. Researchers discovered that hair immersed in a sodium dodecyl sulfate solution lost seven times as much protein as hair immersed in water. Additionally, high concentrations of this ingredient may also cause cell damage and remove natural oils from your hair and scalp.

Contact Dermatitis

For certain people, sulfate shampoo can also cause scalp irritation and contact dermatitis, a type of skin inflammation that results from allergens or irritants. A 1996 study found that exposure to sulfates was more likely to cause skin irritation and contact dermatitis in people with low levels of ceramides, which are waxy lipid molecules found throughout the skin.

It’s important to note that most people will not encounter these issues when using shampoo with sulfates, but it could still be a cause of concern for those with sensitive skin.

Can Sulfates Cause Hair Loss?

Another worry is that these ingredients could cause hair loss. While there’s no scientific evidence directly connecting sulfates with hair loss, irritation could potentially cause temporary hair loss and damage of proteins can lead to breakage.

General Discomfort

Products with sulfates can also cause irritation in the eyes, skin, mouth and lungs, as well as clogged pores and acne issues. Have you ever gotten shampoo in your eyes? Part of what makes it so unpleasant is the sulfates.

To avoid this discomfort, people often slam their eyes shut when they lather on shampoo. Then they scramble to rinse it off. Obviously, people shouldn’t let shampoo pour freely into their eyes, but it’s ironic to be stressed during what is supposed to be a peaceful respite.

Because of these negative effects, many sulfate-based shampoo users feel like they need to choose between daily cleanliness and healthy hair. But if your own health isn’t enough to make the switch, here’s another reason to consider buying shampoo that is sulfate-free.

Are Sulfates Bad For The Environment?

Still not convinced that you need to switch to a sulfate-free shampoo? Our hair isn’t the only thing sulfates can hurt. Once those sulfates wash down the drain, they flow through our sewage systems and eventually empty into the ocean or local rivers and marshes.

An environmental agency in the U.S. Department of the Interior recently demonstrated that sulfates are contaminating freshwater ecosystems such as the Everglades in Florida. This corruption makes fish inedible, and it can poison the surrounding environment as well.

Then there’s the issue of where sulfates come from. Many shampoo producers derive sulfates from palm oil, according to the World Wildlife Fund. To harvest palm oil, most manufacturers clear forests that are often home to endangered species. This practice can also negatively impact local communities that are sometimes impoverished and struggling to survive.

There are ethical manufacturers that produce certified sustainable palm oil, but the process doesn’t change how bad this ingredient is for your hair. SLS can also come from petroleum oil, Stafford said, so sulfate-based shampoos are not the practical choice for consumers who want to reduce dependency on fossil fuels.

Shampoo that is sulfate-free avoids all of these problems while still producing that blissful lather effect. Brands that produce this type of shampoo utilize harmless and sustainable ingredients such as coconut and olive oil. You can apply the product daily without stressing about your hair eroding or getting dried out.

This type of hair care product is likely to be better for your body, and it isn’t harmful to the ecosystems it ultimately drains into. It also makes using shampoo more relaxing, and isn’t that what we look forward to when we take a bath or hop in the shower?

So give sulfate-free shampoo a try. It might work better for your hair, and you’ll be doing your part to help the environment.

If you want to avoid sulfates while also trying to maintain color in your hair, you can also check out the best shampoos for color-treated hair.