What is ferulic acid and why is it in vitamin C serums?Updated a year ago
In skincare, ferulic acid is an antioxidant. This means that it’s able to neutralize some of the damage that’s caused to the skin by external aggressors like the sun, cigarette smoke, and pollution. There are a ton of antioxidants often used in skincare, including vitamin C, niacinamide, vitamin E, resveratrol, and green tea extract.
Ferulic acid is often combined with vitamin C because of a patent owned by SkinCeuticals (which is now owned by L’Oreal). The company found that combining ferulic acid with 15% vitamin C and 1% vitamin E led to a formula that had better longevity while in storage for up to 1 year.
This was determined by looking at the color of the serum after storage, and judging how much discoloration occurred. Ironically, the brand claims that its formula darkening is not a signal that it's losing efficacy - a claim that we find impossible to believe.
They also discovered that ferulic acid helped improve the photoprotective abilities of vitamin C, but not to the extent that a vitamin C serum could actually replace sunscreen.