Key Takeaways
- Sulfates are surfactants — they create lather and strip oil and dirt from your scalp and hair
- There are two main types used in shampoos: SLS (Sodium Lauryl Sulfate) and SLES (Sodium Laureth Sulfate)
- SLS is harsher; SLES is milder but requires a purification step to remove a carcinogenic by-product
- Used correctly and sourced responsibly, sulfates are safe — but they can cause problems for sensitive, dry, or colour-treated hair ?- At Clynn By Nature, we source the best-grade ingredients and formulate specifically to ensure scalp safety
Why Ingredients Matter
This is the science of shampoos. But why care? Because ingredients matter: what goes onto your head can make your scalp dry, and itchy, and sensitive — intolerably irritating. Ever told yourself to stop scratching your head?
Don't worry. You can skip these bad hair days — with just a little help from science. So let's begin with sulfates.
"Consumers have grave concerns about the ingredients in their hair shampoos. Reading materials on the internet and coffee talks with friends have left many feeling uneasy. In this series, we will discuss the nature of chemicals commonly associated with shampoos and how they impact us as end users."
— Lynn Yap, Founder & Cosmetic Chemist, Clynn By Nature
What Are Sulfates?
Sulfates are a class of surfactants — chemicals that attract both water and oil molecules. This dual nature is what makes them effective cleansers: they grab the oil on your scalp, then wash it all away down the drain. They're also responsible for the satisfying lather you get when you massage shampoo into wet hair.
Shampoo as we know it emerged in the 1920s and 1930s. It was in 1930 that Procter & Gamble made the first sulfate-based shampoo — and since then, the basic formulation approach hasn't changed all that much. Sulfates have become the workhorse of the personal care industry, found in shampoos, body washes, toothpastes, and household cleaners.
SLS vs SLES: Meet Laurie and Lauren
There are two types of sulfates used in shampoos. You may think of them as (1) Laurie and his friend (2) Lauren. Laurie's the older one — he's been around longer. He's real fun too, because he easily makes frothy bubbles in whatever kind of water, hard or soft.
Sodium Lauryl Sulfate (SLS) — "Laurie"
The original, older sulfate. Excellent lathering in both hard and soft water. Works well but can be more irritating to sensitive skin and scalps.
Before Laurie came along, many rural regions without access to soft water were using soaps that didn't perform very well. No problem for Laurie — he lathers in any water. And before long, he could be found in soaps for washing yourself, doing the laundry, and cleaning household items.
Sodium Laureth Sulfate (SLES) — "Lauren"
The milder, more modern derivative. Less irritating than SLS, but its manufacturing process produces a carcinogenic by-product that must be removed.
The manufacturing process that creates SLES produces a carcinogenic by-product called 1,4-dioxane.
Important — 1,4-dioxane: Before SLES can be added to any personal care product, manufacturers must subject the chemical through a purification process that reduces levels of 1,4-dioxane to safe limits. Responsible personal care product companies work closely with reliable suppliers to ensure these harmful by-products are not present in finished products. At Clynn By Nature, we verify every batch with our suppliers.
Are Sulfates Good or Bad?
The honest answer: it depends. Used correctly and sourced responsibly, sulfates are generally safe for most people. In fact, people with especially oily scalps or persistent dandruff often find that shampoos containing sulfates are the only products that clean their hair effectively.
The problems start when sulfates are too effective. Their ability to strip dirt and oil is so powerful that they can also remove the natural oils your scalp needs to stay healthy — leading to dryness, irritation, and rebound oiliness.
| Hair / Scalp Type | Sulfate Shampoo | Effect |
|---|---|---|
| Normal / Oily scalp | ✅ Generally fine | Effective cleanse; manages grease and dandruff well |
| Dry / Sensitive scalp | ⚠️ Use with care | May strip too much moisture; can worsen dryness and irritation |
| Eczema / Psoriasis | ❌ Avoid or limit | Can trigger itching, redness, and cracking in the scalp |
| Colour-treated hair | ⚠️ Use with care | Sulfates can accelerate colour fade by opening the hair cuticle |
| Fine / Thinning hair | ⚠️ Use with care | Potential for dryness-related breakage; DHT not addressed |
How Clynn By Nature Approaches Sulfates
At Clynn By Nature, we believe that sulfates are a useful component in shampoos — but only if they exist in the right form and are refined to the right levels. We source the best-grade ingredients and work only with suppliers who can demonstrate consistent purity testing.
More importantly, we don't rely on sulfates alone to do all the work. Our Scalp Shampoo 00 pairs carefully selected cleansing agents with a full suite of active tonic ingredients — so your scalp is cleaned and treated in the same step, without the side effects of over-stripping.
The Bottom Line
Sulfates are not the villain they're sometimes made out to be — but they're also not without risk for certain scalp types. The key is understanding which sulfate is in your shampoo, whether it's been properly purified, and whether the overall formula is designed for long-term scalp health — not just short-term lather.
In the next part of this series, we'll look at parabens — the preservatives that appear in up to 85% of cosmetic products and what the evidence actually says about their safety.
Tags: Sulfates · Shampoo ingredients · Scalp health · The Science · Hair care tips · SLS SLES
Related product: Scalp Shampoo 00 — Clean Refresh — 2-in-1 tonic shampoo · DHT-blocking · Anti-fungal certified · Safe from age 4
Next in series: Part 2 — Harmful Shampoo Chemicals: Parabens and Why They Matter
