Okay, so by now, I’m assuming you’ve heard all about sulfates. Some people love ‘em, some people hate ‘em, some people swear they’re awful for their hair and their hair color, and some people say they give their strands so much shine, softness, and gloss. So, I’m not gonna lie, it’s a little confusing out there. What even are sulfates, and do we want sulfates in our hair products or not?
Fear not, we’ve got ya covered. We brought in the experts to set the record straight. Before we get too deep into it, here’s the TL;DR: “Sulfates are not inherently bad, but they can be aggressive—as could all detergents—if used at too high of a level,” says cosmetic chemist Nick Dindio.
So, to put it simply, sulfates can be bad for your hair, but there’s a lot that goes into figuring out if you should buy that sulfate-free shampoo or not. Personally, I use both sulfate-free and sulfate-full shampoos (I like to switch things up!), and I like both. But that’s just me, so let’s let the experts do the explaining. If you’re saying to yourself, wait, what are sulfates? and just wanna know more about if they’re actually bad for your hair, what hair types should avoid them, and more, this one’s for you. Settle in and keep reading: Class is in session.
What are sulfates?
When we're talking about sulfates in this context, we're referring to sulfated detergents, with the most common being sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), sodium coco-sulfate, ammonium lauryl sulfate, and ammonium laureth sulfate. These days, you often see shampoo and conditioner bottles that say no SLS or no SLES, which means they don’t use those common sulfates. “These ingredients are all surfactants and are very good at their job,” Dindio explains. If you wanna get deeper into the weeds of the science-y stuff, surfactants have a water-soluble portion (that’s the sulfate), and a portion that is oil-soluble (that’s the lauryl, laureth, or coco), so “they can surround particles of oil and dirt to wash them away down the drain,” he adds. Pretty cool. Sulfates are also what give your shampoo that strong foamy lather.
Are sulfates actually bad for your hair?
Soooo, this is a loaded question. The reason sulfates are in your shampoo in the first place is that they’re impressively good at stripping away all the dirt, grime, and product build-up from the hair. But sometimes, they’re too good. To give you an idea of just how rough sulfates can be, dermatologist Mona Gohara, MD, previously told Cosmo that you can even find the same surfactants in your dish soap. And therein lies the potential problem for your hair and scalp, as they can be too stripping and actually remove some of the natural oils and moisture your hair needs.
“On the scalp, sulfates can remove protective lipids and moisture,” says trichologist Sara Hallajian. “For some people, this may trigger tightness, itching, flaking, or rebound oil production, where the scalp produces more oil to compensate for what was stripped away,” she adds.
Is it okay to use shampoo with sulfates?
Depending on your hair type and needs, yes. That strong cleansing effect “can be helpful occasionally, especially for people who apply a lot of product to the hair shaft, but excessive use may leave hair feeling dry or brittle,” says Hallajian. Hair colorist Meri-Kate O'Connor notes that individuals with oily hair or those exposed to a lot of dirt or dust may benefit from sulfates due to their ability to thoroughly cleanse the hair. In this case, you might also want to consider using a clarifying shampoo once or twice a month (BTW, there are sulfate-free clarifying shampoos out there if you prefer).
So unless you're covered in dirt every single day, you definitely don't need to use a clarifying shampoo or sulfate-filled shampoo all that often, only once a week max (even less if your hair is curly, coily, and/or very dry) as a reset cleanse.
Is it better to use a sulfate-free shampoo?
It’s all about balance. “For hair, frequent sulfate use can strip away natural oils that protect the hair shaft, but balanced with a hydrating conditioner, it can help to support the hair shaft,” says Hallajian. Sulfate-free shampoos can be better for some hair types, yes, but that doesn't automatically mean sulfate-filled shampoos are evil. According to Dindio, all the detergents work the same way, but they just have different properties, like foam quality, foam volume, and cleansing power.
As hairstylist Monaé Everett previously told Cosmo, shampoos for oily hair usually contain some sulfates to help break down scalp sebum, and that's totally okay to use sparingly. If sulfates seem to be way too stripping for your hair and it’s feeling dry and brittle, then yeah, that’s probably not the best shampoo for you and a sulfate-free option could be better. Pay attention to your hair and see how it responds.
Which hair types should avoid sulfates?
If sulfates are high up on the ingredient list (like if they’re listed second or third), you might be better off skipping that formula if you have curly, damaged, or dry hair, and instead opt for sulfate-free formulas.
Also, make sure to consider any scalp and skincare concerns you may be dealing with. “For the scalp, aggressive sulfates can be more problematic if you are dealing with a compromised scalp barrier, especially for individuals with inflammation, dandruff, eczema, psoriasis, or hair loss,” says Hallajian. “In these cases, sulfates may worsen irritation or dryness and disrupt the scalp’s microbiome.”
If you color your hair, should you avoid sulfates?
Now, you may be asking, “what about if my hair is colored?” You may be fine to use a shampoo with sulfates, but keep reading for some caveats. Dindio says that it's more about the concentration of the detergent, rather than the detergent itself, meaning that as long as it’s not too harsh, you could be okay. But even the experts don’t completely agree on all this. “Sulfates can oftentimes remove color pigments and chemical treatments—such as keratin treatments—faster than you would like, so I definitely recommend not using them at all, or as little as possible, to help prolong your hair,” says O’Connor. So, I’d say that, while it’s up to you, it's not a bad idea to opt for a sulfate-free shampoo for color-treated hair just to be as safe as possible.
Final verdict:
Basically, though sulfates may be better at cleansing your hair, you def don’t want to use them all the time. It all depends on your needs. I have thick, oil-prone hair and use dry shampoo at least once a week, so using a sulfate shampoo at least once a week is the right option for me. But if you have dry, curly hair, a milder sulfate-free formula is probably gonna be better for you. As Dindio explains, it's more about the concentration of the sulfates than the actual sulfates themselves, but with so many options out there (see above), you definitely don't have to use ‘em if you don’t want to. Free will!
Meet the experts:
- Meri-Kate O'Connor is a Los Angeles-based hairstylist at Cooper Hair Salon in West Hollywood. O'Connor is a colorist, stylist, and extension expert.
- Mona Gohara, MD, is an associate clinical professor of dermatology at Yale School of Medicine, and a board-certified dermatologist at the Dermatology Physicians of Connecticut in multiple locations in CT. Dr. Gohara has previously spoken to Cosmo on the topic of acne face wash.
- Sara Hallajian is a certified trichologist, and founder of âme vitality in Santa Monica, California. With over 13 years of experience as a cosmetologist and advanced training in trichology and integrative health, she specializes in non-surgical hair restoration and evidence-based scalp care.
- Nick Dindio is a cosmetic chemist and the director of research and development for SOS Beauty. Dindio has worked with brands such as Glossier, Oribe, Tata Harper, and ColourPop.Monaé Everett is a celebrity hairstylist, author, and public speaker with over 20 years of experience specializing in natural hair based in Brooklyn, NY. Everett has previously spoken to Cosmo on the topic of sulfate-free shampoos.
Why trust Cosmopolitan?
Catharine Malzahn is a freelance beauty editor with more than five years of experience writing about beauty topics like hair and scalp care.
Catharine Malzahn is a contributing beauty writer at Cosmopolitan and was previously the beauty assistant at Good Housekeeping, Woman's Day, and Prevention.
