Are Sulfates Harmful for Your Hair? Perhaps—Here’s When You Should Avoid Them

Achieving gorgeous, healthy hair is about more than just sticking to a regimen. While consistency is important, you also need to be mindful of the ingredients in your hair care products. Some ingredients, like formaldehyde, are well-known for their negative effects. Others, like sulfates, are a bit more unclear. Sulfates are often considered harmful to hair—but that's not always the case.

When we come across a sulfate-free shampoo, we often assume it's automatically the better choice for our hair. But most of us don’t fully understand what sulfates actually do. The truth is, sulfates aren’t always bad for your hair, depending on your hair type and texture. Let’s clear up the confusion about sulfates in hair care and explain what they are and who should avoid them.

What Exactly Are Sulfates?

"Sulfates are a group of cosmetic and household cleaning agents," explains Ron Robinson, a cosmetic chemist and the founder of Beauty Stat. These ingredients are usually listed on labels as sodium lauryl sulfate, ammonium lauryl sulfate, or sodium saureth sulfate. In hair care products, sulfates act as the primary cleansing agents, helping shampoos create lather and remove dirt, oil, and other impurities from the hair.

If sulfates are responsible for cleansing, why do some people believe they are harmful to the hair? Gretchen Friese, certified trichologist at Bosley MD, explains that sulfates can strip hair of its essential moisture. "Sulfates may remove too much moisture, leaving the hair dry and potentially damaged," says Friese. "They can also cause the scalp to become dry and irritated."

For those with color-treated hair, sulfates can strip away and dull the vibrancy of your hair color, according to Jennifer Korab, a professional hairstylist. Furthermore, if you're getting treatments like a Brazilian blowout, sulfates may reverse the smoothing effects of keratin treatments.

The Advantages of Sulfates in Shampoo

Despite the possible downsides of sulfates, that doesn’t mean everyone should rush to sulfate-free shampoos. "Sulfates have gained a bad reputation due to misinformation and fear-based narratives," says Robinson. "Just because this ingredient might not be suitable for some doesn’t mean it’s harmful to others." Here’s why sulfates are still important.

Effectively Removes Dirt, Oil, and Debris

The main advantage of using a shampoo with sulfates is its ability to effectively eliminate dirt, grime, residual products, and oil from both your hair and scalp. If your hair is very dirty or you’ve been using a lot of products and need a deep cleanse, a sulfate-rich clarifying formula can really rejuvenate your hair and scalp.

Additionally, if your scalp produces excess oil, this formula can help remove the oil, providing more lift and volume to your hair. However, it's important not to overuse it—only use it when necessary to prevent drying out your hair.

More Lather Than Sulfate-free Formulas

Another reason to choose a sulfate-based shampoo is for the rich lather it creates. "Sulfate-free shampoos still clean your hair and scalp, but they won’t produce the usual sudsy lather that you expect from traditional shampoos," says Cleveland. People sometimes overuse the product in an attempt to get that lather, but sulfate-free formulas provide a gentler cleanse, which doesn’t create the same foam.

Which Hair Types Should Skip Sulfates?

Now that we know sulfates can be beneficial for some people, who should steer clear of them? "Understanding sulfates comes down to knowing your hair type and recognizing any treatments or services that are already applied to your hair," says Michelle Cleveland, professional hairstylist and owner of Hair Addict Salon. If you have one of the following hair types, the disadvantages of sulfates may outweigh the benefits, so you might want to consider using a sulfate-free shampoo.

Dry or Sensitive Scalp or Those with Skin Conditions

If you have a dry or sensitive scalp, you might benefit from a sulfate-free shampoo, as it’s gentler and cleans without excessively drying out the scalp. Additionally, if you have a skin condition like eczema or rosacea, switching to sulfate-free products can help reduce itching and irritation.

Try It

Dry, Frizzy, Curly, or Coarse Hair

"If your hair is extremely dry, coarse, or curly, you might want to avoid using products with sulfates," advises Cleveland. Sulfates can strip away natural oils and moisture from the hair, which creates friction between the strands and leads to frizz. A sulfate-free formula will cleanse your hair without removing too much of its natural oils.

Try It

Recently Color-Treated or Chemically Serviced Hair

If you've recently undergone a chemical or color treatment, a sulfate-free shampoo can help extend the longevity of your results.

Try It

The Bottom Line

If you enjoy the lightweight feeling of your hair after using a regular shampoo or need a deep cleanse to remove buildup, a sulfate-based shampoo might be your best option. Friese recommends that people with fine hair textures can use shampoos containing sulfates, but they should keep in mind the potential risks.

Ultimately, as with all things in beauty, the key is to assess your hair type and specific concerns. If you have extremely dry or over-processed hair, or a sensitive scalp, you might want to switch to a sulfate-free formula.