Sulfates in Shampoo: Should You Avoid Them?

Ever wondered why shampoo quickly turns into foam when mixed with water? The answer, for many supermarket shampoos, is the inclusion of chemical foaming agents like sodium lauryl sulfate and sodium laureth sulfate.

Known commonly as sulfates, these ingredients help shampoo mix into water, creating the foamy texture — the lather — you get when you massage shampoo into your hair and scalp. Sulfates are commonly found in mass-market shampoos, including most of the brands you’ll find in your local supermarket.

At low concentrations, sulfates are considered safe to use. However, frequent use of products with a high concentration of sulfates may lead to buildup, which can contribute to cell damage and excess stripping away of natural oils and hair proteins.

From a hair care perspective, this definitely isn’t a good thing. In this guide, we’ll look at how the most commonly used shampoo sulfates can affect your hair, as well as the key reasons why you should avoid shampoos that contain chemical sulfates.

What Are Sulfates in Shampoo? 

Sulfates are surfactants — chemicals that reduce the level of surface tension between shampoo and your skin, so that the shampoo can do a more effective job of cleaning dirt, oil, and dead skin from your scalp and hair — all things that need to be removed regularly for the health of your hair.

Shampoo formulations may employ different types of sulfates like sodium lauryl sulfate (sometimes abbreviated SLS) and sodium laureth sulfate (sometimes abbreviated as SLES).

Sulfates are commonly found in mass-market shampoos, including most of the brands you’ll find in your local supermarket. In fact, a variety of products contain sulfates, from shampoo to liquid dish soap and laundry detergent.

What Does Sulfate Do to Your Hair?

Ever wondered why shampoo quickly turns into foam when mixed with water? The answer is typically the inclusion of sulfates, which make achieving that lather much easier.

When used in shampoo, ingredients like sodium lauryl sulfate and ammonium laureth sulfate amplify the shampoo's effects, allowing it to strip away excess oil from oily hair, which can feel uncomfortable.

Is Sulfate Bad For Your Hair?

Unfortunately, sulfates may also damage your hair. Sulfates can strip away naturally occurring proteins and oils, damaging the keratin, undoing the effects of whatever hydrating products you use, and ultimately leaving your hair feeling brittle and dry.

There have also been rumors over the years that sulfates (including sodium lauryl sulfate, the most common sulfate in hair products) can potentially cause cancer.

Luckily, these rumors aren’t backed up by any scientific evidence. The sulfates used in shampoo and other hair care products are not known carcinogens, and there are currently no scientific studies that show any link between sulfates and cancer.

Still, sulfates can potentially cause damage to your hair when overused. They can trigger protein removal and contact dermatitis — the former, a long-term problem, and the latter, a short-term one.

Sulfates and Hair Protein Removal 

Hair is made of protein — in fact, hair itself is a protein filament. When the protein that makes up each of your hairs is damaged, it can weaken the hair, affecting its strength and appearance.

Sulfates are closely linked with damage to hair protein because, along with the grime, these cleansing agents can also wash away your healthy hair — almost literally. 

One study from 2005 showed that hair immersed in a sodium dodecyl sulfate solution loses two times as much protein as hair immersed in water. This can lead to split ends, breakage and hair that’s difficult to manage.

This problem may affect different hair types differently — fine hair and color-treated hair might be more susceptible than curly hair.

Because of this, sulfates are best avoided if you want to optimize your hair’s health, appearance and strength.

Sulfates and Contact Dermatitis

As a dermatology professional will tell you, sulfates not only strip hair protein. In some people, they can cause severe skin irritation and a painful allergic rash — a condition called contact dermatitis.

That’s why the American Academy of Dermatology Association calls out sulfates as one of the potential irritants for people with conditions like rosacea.

Studies suggest that people with low levels of ceramides — a type of waxy lipid molecule found in your skin cells — are more likely to experience skin irritation and contact dermatitis after exposure to sulfates such as sodium lauryl sulfate.

Not everyone will experience skin rashes or dermatitis after using shampoo or conditioner that contains sulfates. Still, it’s best to avoid shampoos that contain sulfates just in case, as there’s nothing fun about dealing with a scalp rash and the resulting itchy scalp.

Do Sulfates Cause Hair Loss? 

No, sulfates do not directly cause hair loss. While sulfates aren’t directly linked to male pattern baldness, they’re best avoided if you have sensitive skin or naturally thin hair.

A combination of hormones and genetics cause male pattern baldness — namely, a genetic sensitivity to something called dihydrotestosterone, or DHT.

Sulfates aren’t currently known to affect scalp DHT levels and, as such, aren’t directly linked to pattern hair loss in men.

However, sulfates can be indirectly linked to male hair loss. If you’re susceptible to skin irritation from sulfates, you could temporarily lose hair as a result of irritation, turning those particular cleansers into hair loss shampoos. It’s also possible for protein loss from excessive exposure to sulfates to weaken your hair, making breakage more likely.

The Verdict on Sulfate in Shampoos

If you use shampoo with sulfates, all you may notice are the sudsy sensation when you’re lathering them up, or the fragrances they’re scented with.

Unfortunately, you may also notice product buildup, frizzy changes in the texture of your hair, and more skincare issues.

Sulfates can contribute to skin conditions like dryness that could require a dermatologist to address.

If you see these problems, talking to a dermatologist about your symptoms and a hairstylist about other options could help you maintain better hair and skin health.

Sulfate-free products like our hair thickening shampoo, our volumizing shampoo, or our dandruff zinc shampoo are great options to start with. 

A few warnings about the best sulfate-free shampoos, though:

• Compared to sulfate-based shampoos, sulfate-free shampoos can feel a little different. There’s less of a foaming, bubbling effect, meaning it can require some extra water to rinse sulfate-free shampoo from your hair. The routine may take some getting used to.

• Sulfate-free shampoos can also feel less intense, meaning you may not get the “cleansed” feeling you would from a typical shampoo. The shampoo is still effective, but the lack of foaming chemicals can mean it doesn’t have such a pronounced feel on your scalp.

• It’s also worth reading the ingredient label on your other products — from body wash to toothpaste and conditioner — as many mass-market conditioners use ingredients like sodium lauryl sulfate or sodium dodecyl sulfate.

One final word: switching your shampoo isn’t all you can (or should) do. You may also want to explore other forms of hair loss treatment to supplement your shampoo.