Pure vitamin C means L-ascorbic acid, the unmodified molecule and the form with the deepest research behind it. It is an antioxidant, a cofactor your skin needs to build collagen, and an inhibitor of tyrosinase, the enzyme that drives pigment production, which is why one ingredient shows up in products for firmness, dullness and dark spots alike.The clinical literature supports improvements in the appearance of fine lines, uneven tone and photodamage with consistent use, generally at concentrations from about 5 percent upward and at a low pH. The catch is stability: L-ascorbic acid oxidizes on contact with air, light and heat, turning yellow then brown, and an oxidized serum stops delivering what it promised. Japanese formulas often address this with an oil or anhydrous base and small, opaque packaging.Brands talk about spot clearing and radiance. What consistent use tends to deliver is gradual evening of tone and a brighter overall look, most visible on post-blemish marks. Deep-set melasma is a different problem, and one for a dermatologist.Pure vitamin C suits resilient, oily or normal skin that wants the most evidence-backed antioxidant, and it is a good morning partner to sunscreen. It is a poor first choice for sensitive, rosacea-prone or actively irritated skin, where a derivative is kinder. Start two or three times a week, and stop using a bottle once it has darkened.Layer it under sunscreen in the morning. It pairs well with vitamin E and ferulic acid, which help stabilize it, and with niacinamide in ordinary use. Avoid stacking it with a strong acid or a retinoid in the same application if your skin is at all reactive.Ours is a Japanese classic: the Rohto Melano CC Concentration Measures Essence.

Nothing here yet.