Ammonium Lauryl Sulfate

Ammonium lauryl sulfate is a surfactant—a cleansing agent that reduces surface tension between oil and water. It is derived from lauric acid (found naturally in coconut and palm oils) and ammonia. In skincare formulations, it functions primarily as a cleanser and foaming agent, helping to remove oils and impurities from the skin's surface.

This ingredient belongs to the sulfate family of surfactants. Unlike some gentler cleansing agents, sulfates are relatively strong and efficient at breaking down sebum and dirt, which is why they appear in many mass-market cleansers and shampoos.

Ammonium lauryl sulfate is a surfactant molecule with a hydrophobic (water-repelling) tail and a hydrophilic (water-attracting) head. When applied to skin, it surrounds oil and dirt particles, allowing them to be rinsed away with water. This mechanism makes it an efficient cleanser, particularly for removing excess sebum and makeup.

However, this same cleansing action can strip the skin's natural oils if used at higher concentrations or with prolonged contact, which is why irritation is a documented concern.

If using a cleanser containing this ingredient, limit contact time to 1–2 minutes and rinse thoroughly with water. If you have dry or sensitive skin, consider using it only once daily (typically at night) rather than twice daily, and follow immediately with a hydrating toner or moisturiser. Patch test first if your skin is reactive, and discontinue if persistent redness or tightness develops.