The Best Sulfate-Free Shampoo: Get the Facts and Find the One for You
Sulfate-free shampoos promise to leave hair hydrated and more vibrant, so we got the scoop from hair care experts—plus rounded up our faves—to help you make the switch and find the best sulfate-free shampoo for your budget.
Crank on the water, step in the shower and reach for your favorite shampoo. You stand a few inches away from the showerhead and take a minute, or two, to enjoy the rich lather that leaves your hair feeling squeaky clean. But there is a catch. That ultra-lathery shampoo you love possibly contains sulfates and may be doing more harm than good.
Pros and Cons
Finding the best sulfate-free shampoo starts with weighing the pros and cons. Shampoos contain surfactants or detergents, like sulfates, that are cleansing agents used to remove dirt, oil and other residue from the hair. "These ingredients are what give shampoo the rich lather that many associate with a good cleanse," Dr. Joel Schlessinger, board-certified dermatologist and president of LovelySkin.com, says about sulfates. Sulfates are used in most products designed to clean. Morgan Willhite, creative director at Ouidad, says you will find sulfates in shampoos, as well as in industrial and home cleaning products.
In the hair world, sulfates are found in 90 percent of shampoos on the market, thanks to their low cost and effective cleansing properties. "They deeply cleanse, so if you are someone that has buildup on your hair or scalp, or doesn't shampoo often, sulfates can help deeply cleanse and remove the unwanted buildup," Willhite says.
Sounds promising, right? But not so fast. While sulfates have some positive properties, Willhite says they also have the potential to wreak havoc on healthy hair, the scalp and hair follicles because they overcleanse and leave hair dry and dehydrated.
"One downside to sulfates is that they often fade color-treated strands and create unwanted frizz," Schlessinger says. "Additionally, some salon treatments don't do well with sulfates, so your stylist might ask you to switch to a sulfate-free formula after receiving a keratin treatment or a Brazilian blowout."
Schlessinger says there is also a myth that sodium lauryl sulfate may increase the risk of cancer but added that this claim has no scientific basis. "It raises questions," says Dr. Robert Dorin, hair restoration surgeon and owner of the True & Dorin Medical Group. "The 1,4-Dioxane that it contains is known to be a carcinogen." But so far, Dorin says, there have been no studies done to prove sulfates cause a higher incidence of scalp cancer.
The Science Behind Sulfates
Dr. Joseph Cincotta, chief chemist at Federici Brands who holds a doctorate in chemistry, says sulfates have what chemists call a high molecular-charge density, meaning there is a negative charge on one end of the molecule. When in contact with hair, this high charge density causes the hair to swell, releasing oils or dirt from the hair—so what's the catch? "The problem is they also strip out all the vital oils in your hair and on your skin," Cincotta says. "People are starting to move away from them in skin care products and hair care products because they tend to strip. They're too aggressive."
Sulfates attack the proteins found in the hair, and Cincotta says these proteins are essential to hair's strength and flexibility. The feel, look and shine of hair come from the surface, where the surfactants are most concentrated.
"Once you start stripping and breaking down the protein in the hair, the hair will eventually break," Cincotta says. "New hair is produced at the root, but the hair that's already out is not healing itself as your skin would."
Cincotta says the negative effects of sulfates, like the hair becoming rough and dull and losing the color pigments that have been put in, are even worse for people who wash their hair every day with a sulfate shampoo. For those who have never used artificial color on their hair, Cincotta says the loss of color pigments caused by using sulfate shampoos does not happen with natural color, but the hair will still become dry and brittle.
On the other end of the spectrum, sulfate-free shampoos tend to have lower charge densities than those with sulfates. "These sulfate-free surfactants are a lot milder on the hair, on the skin, on the eyes, and they don't swell the hair as much," Cincotta says, "and, therefore, you get less color leaching from the hair."
Switching to Sulfate-Free
While some critics claim sulfate-free formulas do not properly clean hair, Schlessinger argues that shampoos formulated without sulfates use other purifying agents to cleanse the scalp. "They still are going to remove excess oil. The thing is that they won't overdo it. They won't swell the hair, remove the oils from inside the hair," Cincotta says about sulfate-free shampoos. "They'll only remove what's on the surface of the hair, so you will feel like your hair is clean."
Using a sulfate-free formula will leave hair feeling more hydrated, and Willhite says color-treated hair will keep its vibrancy and shine for an extended length of time. When reading labels, look out for ingredients like sodium lauryl sulfate or ammonium lauryl sulfate, which Dorin says are two commonly used sulfates.
"If switching to a sulfate-free shampoo, make sure you hair is thoroughly saturated with water before shampooing," Willhite recommends. "Wash your hair twice, as with the first shampoo you may experience little to no lather. The second shampoo will cleanse deeper, removing the buildup of product, dirt and oil."
The Best Sulfate-Free Shampoo for Your Budget