Most people assume a 10% niacinamide serum will shrink pores overnight and stop oil production by day three. That expectation is wrong. After testing The Ordinary Niacinamide 10% + Zinc 1% Serum ($5.90 for 30ml, $10.90 for 60ml) for 30 consecutive days, the reality is more nuanced. Here is the data. How I Tested: Protocol, Metrics, and Baseline I used […]