Methylisothiazolinone in skincare
A well-known preservative sensitizer, especially problematic in leave-on products.
What to do about it
Avoid if your skin is reactive or you have eczema/contact allergy.
This one matters more in leave-on products — a serum or moisturiser that stays on your skin — than in a cleanser you rinse off within a minute. Skinvio weighs it less heavily for rinse-off formulas for that reason.
Why it's flagged
- Known sensitiser
- Regulatory restriction
How common is it?
Listed on roughly 1 in 40 of the 4,195 product labels in Skinvio's catalogue.
Counted by matching label text, so it reflects how often the name is printed on a label rather than a verified chemical analysis.
Also written as
methylisothiazolinone · mi
Labels rarely agree on naming. Skinvio matches all of these to the same ingredient.
Where this comes from
FDA allergen guidance and Cosmetic Ingredient Review safety assessment history.
This is cosmetic guidance, not medical advice
Skinvio does not diagnose, treat, or cure any skin condition. Ingredient scores describe general formulation patterns, not how your skin will respond. Always patch test, and speak to a licensed clinician about reactions, persistent irritation, or any changing spot or growth.
Related ingredients
Check a whole label at once
Skinvio scans a product's full ingredient list and scores it for your skin type, flagging everything on this list in one pass.
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