What is Chlorella?
Chlorella (INCI name: Chlorella Vulgaris Extract) falls into the marine / algae category — a marine or algae-derived extract. A freshwater green microalga sold as a detoxifying and peptide-rich active. It sits alongside spirulina, which is rated 4 here, in the algae group that pore-clogging lists treat with caution. It is named on the AcneClinicNYC pore-clogging ingredient list, but that list does not publish a 0-5 comedogenic score for it and no Fulton-derived table we cite carries one. We therefore leave it unrated rather than invent a number — treat the listing itself as the signal.
You may see it on labels as Chlorella, Chlorella Vulgaris Extract, Green Algae, so it can hide under more than one name in an ingredient list.
Where Chlorella shows up
As a marine or algae-derived extract, Chlorella typically appears in anti-ageing serums, masks, and 'marine' or 'seaweed' branded skincare.
Is Chlorella bad for acne-prone skin?
Because no reliable comedogenic score exists for Chlorella, judge it by how your own skin responds rather than by a number.
Worth flagging: Chlorella's rating is disputed. Credible sources land on different numbers, which is why we show a range rather than a single score — and why your own experience is the best tiebreaker.