H.A. Supreme Vita Brightening Concentrate Serum

Apply it to damp skin after cleansing and toner, then seal it with moisturizer so the water does not evaporate. Skipping that last step can leave skin feeling tighter instead of softer.

Derivatives are generally more stable and less irritating than ascorbic acid, though they tend to work more slowly. That trade-off often suits sensitive skin.

Yes, a hydrating serum with a vitamin C derivative usually layers fine with a nighttime retinoid. If you get flaking, move the serum to your morning routine.

This is a concentrated serum used sparingly, so 30 ml generally covers two to three months of daily use. If plain hydration is all you want, Hada Labo's basic lotion does that for less.