Close-up of a brown eye, brow and the thin under-eye skin, showing fine skin texture and a few freckles

Retinol Sandwich Method: How to Do It, and Retinal vs Retinol

How the retinol sandwich method works, how to start vitamin A slowly, and how retinal and retinol differ.
Close-up of a woman with dewy skin and foamy cleanser on her cheek, dabbing her face with a white cleansing sponge

Skincare Ingredients Not to Mix: What to Separate and Why

No pair is banned for everyone, but retinoids, exfoliating acids and strong vitamin C are worth separating. Add one active at a time and let your skin set the pace.