Amodimethicone

Amodimethicone is a conditioning silicone polymer used mainly in hair products (typically ~0.1–3%) that forms an inert, occlusive film and is not a common primary irritant in clinical or patch-test data. When reactions occur, they are usually rare and more often attributable to accompanying surfactants, fragrance, or preservatives rather than the silicone itself. For highly reactive or eczema-prone patients, I still assign a low-but-nonzero score because leave-on scalp/skin exposure can occasionally trigger follicular irritation or intolerance in a small subset. Safety Notes: In mass-market conditioners, shampoos, and rinse-off masks, amodimethicone is often used at low levels (~0.05–0.5%) as part of a silicone microemulsion/deposition system to improve slip and conditioning without heavy buildup. Leave-on sprays/creams and intensive smoothing/repair masks commonly sit around ~0.2–2% for stronger frizz control and fiber feel. High-strength consumer-available smoothing serums and concentrated mask systems can reach about 3–5% amodimethicone (usually supported by emulsifiers and amine-functional silicone compatibility aids), while higher levels are uncommon due to stability/feel and diminishing returns rather than regulatory limits.