La Roche Posay is a staple French skincare brand for a reason. With 10 percent vitamin C, this serum also includes salicylic acid to slough off dead skin cells and the dipeptide neurosensine to ...

Despite its efficacy, vitamin C is notoriously unstable and can quickly go from a hyperpigmentation-zapping wonder ingredient to a $60 bottle of smelly serum. That’s why it’s important to find ...