Coal Tar
Coal Tar
Effective for psoriasis and dandruff, and strongly comedogenic. Not for facial use.

How solid is the pore-clogging number
Coal Tar rates 5 of 5 — strongly occlusive; widely avoided by acne-prone users. The rating is graded established. Traceable to published comedogenicity testing and consistent across sources.
It describes the raw ingredient in isolation. In a finished product, how much is present and where it sits in the list matter just as much. Check a whole label to see it in context.