A water-soluble antioxidant that helps brighten uneven tone, supports the look of firmness by aiding the skin's collagen-making process, and adds daytime protection alongside sunscreen.
L-ascorbic acid works in three calm, well-described ways. First, it acts as a helper (cofactor) for the enzymes prolyl and lysyl hydroxylase, which stabilize and cross-link collagen molecules — this is how it supports the skin's own collagen structure and the look of firmness over time. Second, it works as an antioxidant by donating electrons step by step to neutralize free radicals generated by UV and pollution; on its own it adds some daytime photoprotection, and this effect is described as roughly four-fold stronger when paired with vitamin E. Third, it helps even out tone by interacting with copper ions at the active site of tyrosinase, the enzyme that drives melanin production, gently reducing excess pigment formation for a more uniform appearance. Because it is unstable, exposure to light and air oxidizes it to dehydroascorbic acid, which turns the product yellow and signals reduced activity.
The concentration that actually makes a difference, and whether this fits YOUR skin profile, lives in the MHS BLOOM app.