Lauryl Betaine

Lauryl betaine is an amphoteric surfactant used in cleansers/shampoos (often a few percent up to ~10% in rinse-off formulas) that can still disrupt the stratum corneum and cause stinging or dermatitis in compromised or eczema-prone skin. Patch testing and real-world use show it is generally milder than harsh anionics like SLS, but it is not reliably non-irritating—especially with frequent use, higher surfactant loads, or prolonged contact. Given its surfactant nature and the risk profile in sensitive populations, it warrants careful introduction and avoidance on actively inflamed skin. Safety Notes: Lauryl betaine (an amphoteric surfactant/foam booster) is observed at low levels (~0.1–1%) in mild facial cleansers, baby washes, and micellar/low-foam systems where it is used mainly to reduce irritation and support viscosity/foam. Most mainstream rinse-off cleansers and shampoos commonly use it in the mid single-digits, while high-foaming consumer products (clarifying shampoos, body washes, bubble baths, and some “sulfate-free” surfactant concentrates) can reach ~10–20% as part of the total surfactant blend; it is rarely used at meaningful levels in leave-on skincare due to irritation/tack risks.