Other

Methylisothiazolinone

A common preservative that has faced significant scrutiny in recent years due to its potential to cause allergic contact dermatitis in some users.

preservativeantimicrobialallergen-flagged

✓ Safe

Comedogenic Rating

0/5

Irritation Potential

0/5

What is it?

Methylisothiazolinone (MIT) is a preservative effective against bacteria and fungi, but has been identified by dermatology research as a significant cause of allergic contact dermatitis, leading to use restrictions in leave-on products in several regions.

Used in rinse-off products like shampoos and cleansers, where exposure time is shorter, reducing allergy risk relative to leave-on use.

Key Benefits

✦

Effective antimicrobial protection

Helps prevent bacterial and fungal contamination in formulas.

Suitable for

rinse-off products primarily; those with sensitive skin should check for it on labels

Main Actions

✓ preservation✓ antimicrobial protection

When it may be insufficient

It is a recognized contact allergen for a meaningful subset of users — many regions now restrict or ban its use in leave-on cosmetics due to rising sensitization rates.

Frequently Asked Questions

What does Methylisothiazolinone do for skin?

Used in rinse-off products like shampoos and cleansers, where exposure time is shorter, reducing allergy risk relative to leave-on use.

Who should use Methylisothiazolinone?

Methylisothiazolinone is suitable for: rinse-off products primarily; those with sensitive skin should check for it on labels.

Are there any warnings about Methylisothiazolinone?

It is a recognized contact allergen for a meaningful subset of users — many regions now restrict or ban its use in leave-on cosmetics due to rising sensitization rates.

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