What a 5/5 rating means
On the comedogenic scale, a 5 is the top of the scale — highly likely to clog pores when used at meaningful concentration. That means Red Algae 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 Red Algae near the end of a label is present in tiny amounts and matters far less than the same ingredient near the top.
About Red Algae
It is a marine or algae extract, marketed for minerals and antioxidants. A red seaweed extract rated 5/5 for comedogenicity in classic lists.
On a label it can read as Red Algae, Rhodophyceae Extract, Rhodophyta — worth knowing when you scan an ingredient deck.
Red Algae in makeup and skincare
It features in 'anti-ageing' serums, masks, and luxury complexion products. Its irritancy is rated separately at 2/5, which is low.
Lower-rated alternatives to Red Algae
If you want a similar role with a friendlier comedogenic score, consider:
- Hyaluronic Acid — comedogenic rating 0/5 (Low risk).
- Niacinamide — comedogenic rating 0/5 (Low risk).