Microcrystalline Cellulose

Microcrystalline cellulose is an inert, insoluble plant-derived polymer used mainly as a bulking agent, stabilizer, or texture modifier in leave-on and rinse-off products, typically at low-to-moderate percentages. Clinical experience and patch-test data indicate it has very low irritation and sensitization potential, with reactions being uncommon and usually related to mechanical rubbing in very compromised skin rather than chemical irritancy. Given the need to protect highly reactive eczema-prone patients, it best fits the 'exceptionally gentle' category rather than absolute inertness. Safety Notes: In commercial skincare, microcrystalline cellulose is often used at very low levels (~0.05–0.5%) as an anti-caking/processing aid or rheology modifier in lotions, creams, and some powder-to-cream formats. More commonly it appears around ~1–5% as a texture/bulking and stabilizing agent (often alongside cellulose gum/CMC) and as a mild physical exfoliant or sensory modifier in leave-on products. The highest consumer OTC levels are seen in cellulose-based exfoliating scrubs, peeling gels, and gommage-type formulas where insoluble cellulose is used as the primary abrasive/roll-off solid phase, reaching ~10–20% in some high-solids systems (with higher loads being increasingly constrained by spreadability, viscosity, and consumer sensory).