Through that reporting, we arrived at some metrics for the ideal formula: a vitamin C concentration of 5% to 20% an ideal ... We loved how quickly Obagi Professional-C Serum absorbed—but on ...

I used to think glowing skin came with a high price tag—specifically, the $150+ I was dropping on a luxury vitamin C serum ...

“Vitamin C can be irritating at concentrations above 20 percent,” says Lal ... effects,” she said in a video interview. Obagi’s vitamin C serum is super lightweight, but it still makes ...