What a 4/5 rating means
On the comedogenic scale, a 4 is in the high-risk band, with a real likelihood of clogging pores on acne-prone skin. That means Algin deserves attention if you break out easily, especially when it appears high on an ingredient list.
One thing the number cannot tell you is concentration. Ingredients are listed in descending order, so Algin near the end of a label is present in tiny amounts and matters far less than the same ingredient near the top.
About Algin
It is a thickener that controls how a product flows and feels. A brown-algae thickener rated 4/5 on both comedogenic and irritancy axes in classic testing.
On a label it can read as Algin, Sodium Alginate, Alginic Acid, Alginate — worth knowing when you scan an ingredient deck.
Algin in makeup and skincare
It sets the consistency of gels, liquid foundations, and serums. Its irritancy is rated separately at 4/5, which is worth noting for sensitive or reactive skin.
Lower-rated alternatives to Algin
If you want a similar role with a friendlier comedogenic score, consider:
- Squalane — comedogenic rating 1/5 (Low risk).
- Niacinamide — comedogenic rating 0/5 (Low risk).