Sodium lauryl sulfate and ammonium lauryl sulfate show up mainly in cleansers.

If you’ve picked up a bottle labeled with SLS or SLES and wondered what’s really going on, you’re not alone. Those acronyms pop up a lot in cleansers, shampoos, and body washes, but what they mean and why they’re there isn’t always obvious. Let me break it down in plain terms, with a few practical takeaways you can use next time you read a label.

SLS and SLES: what they are, and what they do

Sodium lauryl sulfate (SLS) and ammonium lauryl sulfate (SLS, with different counterions) are surfactants. Think of surfactants as the “bridge builders” of the cleaning world. They help water mix with oil, dirt, and grime. When you lather up, these molecules line up at the surface where water and oil meet. One end loves water (hydrophilic), the other loves oil (lipophilic). That dual personality lets soap loosen oils and carry them away with the rinse. The result? A foamy, satisfying cleanse that leaves skin and hair feeling refreshed rather than coated.

In practical terms, that cleansing power is exactly why SLS and SLES show up where you wash. They’re superb at creating rich lathers—perfect for shampoos, body washes, facial cleansers, and sometimes dish soaps too. The foam feels good, and the product spreads easily. For many people, foam equals clean—so these ingredients have earned a big role in many formulations.

Why cleansers love these ingredients

Let’s talk about what cleansers actually do for your skin and hair. A cleanser’s job isn’t just to wipe stuff away; it’s to lift dirt, oil, and environmental gunk so water can rinse it off. Surfactants like SLS and SLES lower the surface tension of water, so it can grab and carry away particles that would otherwise cling to your skin. The foaming texture you get with these ingredients isn’t just a sensory cue; it’s a sign of the cleansing action at work.

Cleanser formulas often balance surfactants with other ingredients. You’ll see a mix of:

• Additional surfactants that are milder or specialized for scalp and skin.

• Humectants and emollients to keep the skin from drying out.

• pH adjusters to keep product compatibility with the skin’s natural acidity.

That blend helps ensure you feel clean without feeling “stripped,” provided you don’t have very sensitive or reactive skin.

Where you’ll typically find these ingredients

If you flip over a bottle and scan the ingredients list, you’ll probably spot SLS or SLES near the top, especially in products designed to wash away oils and dirt. They’re common in:

• Shampoos and conditioner washes

• Facial cleansers and makeup removers

• Body washes and bar cleansers that want a luxurious lather

They might show up in households across many brands because the cleansing action is reliable, predictable, and cost-effective. That practical performance matters in both everyday routines and more specialized products.

Moisturizers, sunscreens, and exfoliators: what’s different

To keep things straight, here’s how the other categories you mentioned usually differ from cleansers—why they don’t rely on SLS/SLES as their main action.

• Moisturizers: These are about hydration and barrier support. They lean on emollients (like esters and oils that smooth the skin) and humectants (like glycerin or hyaluronic acid that attract water). They don’t need strong detergents, so you won’t typically see SLS or SLES listed as the star ingredients. If a moisturizer has surfactants at all, they’re usually mild emulsifiers that help blend oils and water without stripping moisture.

• Sunscreens: The primary job here is to absorb or reflect UV light. Active UV filters do the blocking, while other ingredients help with texture and stability. Surfactants may appear, but they’re not the feature. You’ll often see silicones, esters, and film-forming polymers that help the product spread evenly on the skin and stay put—far different from the cleansing action of SLS/SLES.

• Exfoliators: Exfoliation means removing dead skin cells to reveal fresher skin underneath. Exfoliants can be physical (grains, beads) or chemical (AHAs, BHAs). Some exfoliators use mild cleansing agents to help the granules glide, but the star action is the smoothing or chemical reaction, not heavy detergency. If you’re shopping for a scrub, you’ll notice the focus is on abrasion or chemical activity, not on producing copious foam.

Practical notes for readers: reading labels and choosing products

If you’re trying to decide which products suit your skin or hair, a few practical tips can help you navigate labels without getting overwhelmed:

• Look at the top of the ingredient list. The higher an ingredient appears, the more of it is in the formula. If SLS or SLES are listed near the top, expect a strong cleansing action and a noticeable lather.

• Consider your skin type. People with sensitive or reactive skin may prefer sulfate-free cleansers or those that use milder surfactants (like coco-glucoside or decyl glucoside) combined with soothing additives. Patch testing a new product is a smart move if you’re prone to irritation.

• Check for supporting ingredients. A cleanser might include glycerin, panthenol (pro-vitamin B5), or ceramides to support moisture. If your skin tends to dry out after cleansing, these additions can balance the cleansing power a bit.

• Remember there are sulfate-free lines. In recent years, many brands have crafted sulfate-free cleansers for people who want a gentler cleanse or have sensitive skin. These products often rely on different surfactants that are milder but still effective at cleaning.

A quick note about safety and experience

Surfactants do a lot of heavy lifting, so it’s natural to wonder about safety. In general, SLS and SLES are considered safe for use in cosmetics at common product concentrations. However, they can irritate very sensitive or compromised skin, especially with frequent or prolonged exposure, or when combined with fragrances and certain other additives. If you notice redness, itching, or burning after cleansing, it’s a sign to pause and try a gentler option.

If you’re curious about the science, here’s the gist: SLS and SLES are an economical way to create effective cleansers with a satisfying lather. But “effective” doesn’t always mean “best for every person.” Skin is personal—there are days when a mild foaming cleanser hits the spot, and days when a fragrance-free, sulfate-free formula feels like a better fit.

A small digression that still matters

Here’s a little real-world aside that many people relate to: the sense of ritual around washing. Some folks love the rush of a big foam—it's almost meditative, washing away the day as the suds glow. Others prefer a simple, quick rinse and a clean finish without the extra bubbles. Both camps have products designed to accommodate their preferences. The key is knowing what you’re buying and how it aligns with your routine, not blindly chasing a super-lather. In short, your personal routine should reflect your needs, not just a marketing hook.

Putting it all together: a friendly guide

If you want a concise takeaway:

• SLS and SLES are surfactants that power cleansing and foaming. They’re common in cleansers, shampoos, and body washes.

• Cleansers benefit from these ingredients because they help lift and rinse away dirt and oil.

• Moisturizers, sunscreens, and exfoliators aren’t built around strong detergents. They focus on hydration, UV protection, or skin renewal, with milder formulations or specialized active ingredients.

• If sensitive skin is a concern, look for sulfate-free options or products that use milder cleansers, and don’t forget to patch test new products.

• Reading labels helps you tailor your routine to your needs, balancing cleansing performance with comfort and skin health.

A closing thought

Routines are personal—and that’s a good thing. The same cleanser that makes one person feel wonderfully refreshed might irritate someone else. That’s not a flaw in the product; it’s a reminder that skin chemistry is wonderfully varied. So next time you’re in front of a shelf, take a moment to consider what your skin actually needs: a thorough cleanse, a comforting touch, or a gentle pat of hydration after the wash. And if SLS and SLES appear on the label, you’ll know exactly what they’re doing there and why they matter.

If you want, I can help you compare a few popular cleansers side by side, pointing out where SLS and SLES show up, what milder options exist, and how to pick the best match for your routine. After all, a thoughtful choice today can make your next wash feel just right.