Perfecting your hair care routine can be a journey of trial and error, and often involves a lot of questions to determine how to best take care of it. How porous is your hair? What curl pattern or hair type are you? How dense is your hair? How much hydration does your hair need? What styling products (creams, gels, sprays, puddings, leave-ins) work best for your hair? How often should hair be washed? The list goes on and on. But something particularly important that should be on your radar are the ingredients that are in said products. That includes sulfates, one of the most hotly contested additives in the hair care world.
In general, “Sulfates are a cleaning agent made of mineral salts that contain sulfur,” says Sarah Lund, style master at Kevin Murphy. “It’s one of the main ingredients that allows shampoo to lather.” Without sulfates, you would not experience those satisfying suds when you wash your hair. The divide between sulfate and sulfate-free products has gone on for years. Many claim sulfate-free as the better-for-your-hair option as it offers a gentler clean — but what is it about sulfates that might actually be needed in hair products? And are there any hair types that should be avoiding this ingredient altogether?
Ahead, everything you’ve ever wanted to know about sulfates, straight from industry experts.
What Exactly Are Sulfates?
At their most basic level, sulfates are a type of cleaning agent. More specifically, they are a surfactant, a collection of molecules that attract water and oil and strip the dirt and oil from your hair. They are what make your shampoo sudsy, according to Kim Kimble, celebrity hairstylist.
There are three types of sulfate compounds: sodium laureth sulfate, sodium lauryl sulfate, and ammonium laureth sulfate. Each type is different in intensity and can potentially cause irritation to the scalp. Sodium laurel sulfate and sodium laureth sulfate are most commonly found in hair care products.
“Sodium laureth sulfate is the milder form,” says Nick Stenson, Matrix artistic director. “So if you’re concerned about drying, you will want to choose that over sodium lauryl sulfate.”
How Sulfates Work in Shampoo
Sulfates help a shampoo to remove oil and dirt from your hair. However, hair needs some of its natural moisture and oil to remain healthy. If the concentration of sulfates is too high (above 15%) in a shampoo, it can strip away too much — leaving hair dry and brittle.
“Any shampoo that has a high concentration of sulfates can be damaging,” says Seamus McKernan, Nioxin top artist and master hairstylist at Golden Fleece Salon. “Sulfates are not the enemy but may not be ideal if your hair is already prone to dryness.”
When hair is stripped of its natural oils you risk the chance of not protecting the hair shaft from everyday external factors like dirt, pollution, and pollen, all of which can stress and damage your hair further.
Are Sulfates Safe For Your Hair?
According to McKernan, the benefit of sulfates is that they allow the scalp to breathe because of how effective they are at removing debris. “Sulfates act as cleansing agents and can help optimize the scalp environment,” he tells TZR. When you apply a sulfate shampoo to your hair, the SLS — sodium laurel sulfate or sodium laureth sulfate — attaches to the oils and impurities in your hair. Then, when you rinse the shampoo out, the SLS will attach to the water to free it of the oil and dirt — resulting in cleaner hair.
The concern with sulfates, however, is the dryness and irritation they can often bring. Sulfates don’t just remove some oil — they removes all the oil, even the beneficial ones. “Sulfates can dry out the hair and cause color to fade,” says Dr. Iris Rubin, dermatologist and founder of SEEN Hair Care. The dryness can then lead to brittleness and lack of shine. With the continued overuse of sulfate products and the reduction of natural oils, your scalp will overcompensate and produce more oil causing greasy hair, starting a vicious cycle of hair damage. Similarly, if you have color in your hair, the dyes will fade much quicker with a sulfate formula than if you swapped to a sulfate-free option.
If you have curly hair or if your hair is prone to dryness, you will want to avoid sulfates to prevent further drying. “It would be wise to choose products that provide gentle cleansing without stripping or drying the hair and scalp,” says Howard McLaren, co-founder and creative director of R+Co. McKernan compares the overuse of sulfates as adding too much salt to food, in that it could be beneficial to hair (cleansing) but too much of it could be detrimental (drying and irritation.)
For that reason, if you are using a sulfate shampoo, the best thing to do is follow up with a hydrating conditioner or hair mask that will keep your hair adequately moisturized. If you’d rather avoid sulfates altogether, remember that because sulfate-free products don’t lather and don’t have that oil-removing power, they require a much more rigorous scalp massage to get your hair and scalp clean.
If you don’t have curly, dry, or color-treated hair, sulfates don’t pose as much of a problem. Again, sulfates are not always a bad addition to your hair care routine, especially if your scalp is particularly oily, or if your hair and scalp is getting dirty on a regular basis (like if you work out frequently, work outside, etc). In those instances, a sulfate shampoo might actually be beneficial to get your hair and scalp clean. As long as you have moisturizing conditioner and styling products, you should be able to retain the moisture and natural oils that a sulfate shampoo would strip away if used alone. When in doubt, be sure to look at the ingredient list to note which surfactant is utilized in the formula, and make a call based on the current condition of your hair.