Sulfates

Let's Talk Sulfates

Sulfates are the ingredient that basically started the whole "clean hair care" conversation. They're a type of strong surfactant (a.k.a. cleanser) — the reason your shampoo lathers up so satisfyingly. That foam doesn't actually mean it's cleaning better, by the way. It just feels nice.

On a chemistry level, sulfates have a negatively charged head that grabs onto oils and dirt so water can rinse them away. Sounds great — except it doesn't always know when to stop. It can strip your hair's natural protective oils too, leaving strands feeling dry, rough, and tangle-prone.

How Do Sulfates Affect Curls & Waves?

The Case Against Sulfates

This is the big one that Lorraine Massey warned about in Curly Girl: The Handbook — stripping away natural oils robs your hair of moisture and can leave it looking dull and lifeless. For curly and wavy hair that's already prone to dryness, that's not ideal.

There's also the frizz factor. Strong cleansers like sulfates can increase negative charges on the hair strand, and those charges repel each other — hello, flyaways.

And scalp irritation? While it's often cited as a reason to ditch sulfates, the reality is more nuanced. Lab studies showing irritation use isolated sulfates at concentrations way higher than what's in your shampoo. In a properly formulated product, most people's scalps handle sulfates just fine (unless you have a genuine sensitivity).

The Case For Sulfates

Here's where it gets interesting. Plenty of curly and wavy-haired people actually find sulfates help their hair — especially if you have a looser wave pattern or an oily scalp. A thorough cleanse removes product buildup that can weigh down your waves and flatten your volume.

Some people use a sulfate shampoo every wash and love it. Others keep one on hand as a monthly clarifying reset. There's no single right answer — it depends on your hair.

Not All Sulfates Are Created Equal: SLS vs. SLES

This is where the nuance lives. Sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES) sound nearly identical, but SLES goes through a process called ethoxylation that gives it a larger, gentler molecular structure. It's less likely to penetrate your skin and generally less stripping.

Then there's ammonium lauryl sulfate (ALS) and ammonium laureth sulfate (ALES), which are also considered milder options. Not all sulfates behave the same way, and the specific formulation matters more than the ingredient name alone.

The Bottom Line: Should You Avoid Sulfates?

The honest (and slightly boring) answer: it depends on the whole product, not just one ingredient. Shampoos are formulas — they blend sulfates with mild co-surfactants, conditioning agents, humectants, and more. A well-formulated sulfate shampoo can actually be gentler than a poorly-made sulfate-free one.

We still flag sulfates for anyone following the Curly Girl Method strictly. But as you build your routine, keep an open mind. Ingredients don't exist in isolation — they're part of a bigger picture. A sulfate shampoo might end up being exactly what your hair needs, whether that's as a weekly staple or an occasional deep-clean moment.