What Is Ammonium Laureth-9 Sulfate?
Ammonium Laureth-9 Sulfate is a surfactant derived from lauryl alcohol, a fatty alcohol most often sourced from coconut or palm kernel oil. The lauryl alcohol is first reacted with ethylene oxide to attach an average of nine ethoxy groups, a step that increases water solubility. The resulting ethoxylated alcohol is then sulfated and neutralized with ammonium hydroxide, producing a gentle, water-friendly salt that carries a negative charge in solution.
The ingredient emerged in the 1970s when formulators searched for cleansers that offered the rich foam of traditional sulfates without the harsh feel. By adding ethoxy groups they found a way to soften the cleansing action, giving rise to the “laureth” family of surfactants. Today Ammonium Laureth-9 Sulfate appears in everyday rinse-off products like shampoos, body washes, liquid hand soaps, bubble baths and facial cleansers. It is also blended into scrubs, exfoliating masks and some shaving creams where dense, stable foam is a priority.
Ammonium Laureth-9 Sulfate’s Cosmetic Benefits/Uses
This multitasking surfactant makes formulas both effective and pleasant to use
- Cleansing: Its amphiphilic structure lifts away oils, sweat and dirt then rinses them down the drain, leaving skin or hair feeling fresh without a heavy residue
- Foaming: It produces a rich, cushiony lather that spreads easily, helps distribute other ingredients evenly and adds a sensory cue that the product is working
Who Can Use Ammonium Laureth-9 Sulfate
Most skin and scalp types tolerate Ammonium Laureth-9 Sulfate well, including normal, oily and combination skin. Dry or very sensitive skin may find even this milder sulfate a bit stripping if left on for long periods, so rinse-off formulas are generally preferred for those groups. People with eczema or compromised skin barriers should choose low concentrations or gentler alternatives if irritation is a recurring issue.
The ingredient is typically plant-derived from coconut or palm kernel oil and is not processed with animal by-products, so it fits vegan and vegetarian preferences. That said, anyone avoiding palm derivatives for environmental reasons should check a brand’s sourcing policies.
No data indicate that topical use poses a risk during pregnancy or while breastfeeding. This is not medical advice; expecting or nursing mothers should review any skincare product with their healthcare provider to be safe.
Ammonium Laureth-9 Sulfate does not increase photosensitivity, and there are no known systemic interactions from its use in rinse-off personal care items.
Potential Side Effects/Adverse Reactions
Reactions to Ammonium Laureth-9 Sulfate vary from person to person. The points below outline possible but uncommon effects; most users experience none of them when the ingredient is formulated correctly and used as directed.
- Skin dryness
- Mild itching or tightness
- Redness or irritation, especially on already sensitive or broken skin
- Eye stinging if the product accidentally contacts the eyes
- Scalp flakiness when used in very high concentrations or with frequent washing
If any discomfort, redness or other adverse effect occurs, stop using the product and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 1 / 5
Ammonium Laureth-9 Sulfate is highly water soluble and rinses off cleanly, leaving little to no residue that could block pores. Its molecular size and negative charge make it less likely to linger in follicular openings compared with heavier oils or waxes, which is why the rating is a low 1 rather than a full 0. In practical terms it is considered safe for skin that breaks out easily.
Because it is used primarily in wash-off products where contact time is short the chance of it contributing to blackheads or pimples is minimal. Only in very concentrated leave-on formulas would pore clogging become a remote concern, and those are uncommon.
Summary
Ammonium Laureth-9 Sulfate works as a dual cleanser and foam booster. Its amphiphilic structure grabs onto oil and dirt with one end while the other end stays friendly with water so grime lifts away when you rinse. The nine ethoxy groups soften the sulfate’s edge, giving you a creamy lather that feels gentle yet still gets the job done.
While not as famous as sodium lauryl sulfate it shows up in plenty of modern shampoos, body washes and facial cleansers aimed at users who want a big foam feel without the squeaky-clean harshness of older sulfates.
Overall safety data rate it as low risk when used in typical rinse-off concentrations. It seldom irritates and carries virtually no systemic concerns, though anyone trying a new product should still patch test first to make sure their unique skin plays nice.