Simethicone

Simethicone (a silicone-based skin protectant/occlusive and slip agent) is typically used at low-to-moderate levels in creams, lotions, and barrier products and is widely considered non-sensitizing with very low irritancy in patch testing and clinical use. True irritation or allergy is uncommon and usually related to the overall formula rather than simethicone itself, but in severely compromised skin any film-former can rarely contribute to occlusive discomfort or trapping of other irritants. For patient safety in highly reactive/eczema populations, it fits best as exceptionally gentle rather than completely inert. Safety Notes: In consumer skincare, simethicone is most often used at low levels (~0.1–1%) as a slip agent, anti-foam/processing aid, and skin protectant/emollient component in moisturizers, primers, sunscreens, and cleansers (rinse-off typically at the low end). Higher-strength OTC products marketed as barrier/skin-protectant creams, chafing/friction balms, and some “silicone-rich” smoothing primers commonly reach ~2–5% total simethicone for a more occlusive, blurring feel. This range reflects observed commercial usage; higher levels are limited by sensory, stability, and regulatory/product-positioning considerations rather than a strict cosmetic maximum in major markets.