Chitosan is a naturally derived polysaccharide (from chitin) used in skincare as a film-forming, moisturizing, and mild antimicrobial ingredient that can improve product texture and skin hydration. It is also studied for wound-healing support and as a carrier for other actives.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation or redness | Uncommon | Generally well tolerated topically; transient irritation possible in sensitive skin. |
| Contact dermatitis / allergic reaction | Rare | Allergic sensitization reported infrequently. |
| Reaction in shellfish-allergic individuals | Rare | Often shellfish-derived; theoretical concern though topical reactions are uncommon. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.