Niacinamide
Niacinamide
Strong evidence for barrier function, sebum control and pigmentation at 2-5%.

How solid is the pore-clogging number
Niacinamide rates 0 of 5 — no observed follicular occlusion in testing. 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.