There’s no debate over the place vitamin C deserves in every skin-care routine. A potent antioxidant, a quality vitamin C serum can effectively fend off visible damage from UV rays and blue light, shield from free radicals, plus help fade existing hyperpigmentation and dullness. Like we said, no question there.
However, vitamin C, aka ascorbic acid, can come in a variety of forms and combinations. Some products only contain vitamin C, others may contain ingredients such as hyaluronic acid to aid in plumping the skin, and certain formulas may contain additional actives in order to boost results and increase the vitamin’s stability.
If you’re wondering what stability in the world of serums means, you’re not alone. Cosmetic chemist Ginger King says the buzz word actually means, “the ascorbic acid content in the product is stabilized via a specific delivery system and or pH, heat, light degradation control so when the product delivers onto the skin, you still get the benefits of vitamin C such as skin plumping and brightening.”
The most popular stabilizer of the bunch? Ferulic acid, found in best-selling products such as SkinCeuticals C E Ferulic ($182) and Drunk Elephant C-Firma Day Serum ($79).
Why does my vitamin C serum stink?
While ferulic acid has a long list of benefits, especially when added to vitamin C—San Antonio, TX dermatologist Vivian Bucay, MD says it stabilizes its antioxidants and increases their effects—it also has another not-so-pleasant effect when added to vitamin C.
If you’ve tried a serum combining vitamin C and ferulic acid, you’ve likely noticed its scent has a bit of a bite to it, unlike their fresh, orange-scented or unscented counterparts. The reason, according to cosmetic chemist Stephen Alain Ko, is the combination of vitamin C and ferulic acid.
“Ascorbic acid in water doesn’t have a smell (when it’s not old), but some of the ingredients that have been shown to improve its photoprotective effects, such as ferulic acid, can have a strong smell,” adds Ko.
Dr. Bucay agrees, adding that it’s normal for serums containing ferulic acid to have a strong, almost unpleasant smell. However, the benefits far outweigh the couple of seconds you’ll notice it when applying. “Ferulic acid is an antioxidant and also stabilizes vitamin C. It has been shown that the antioxidant effects of a serum containing vitamins C and E and ferulic acid are much greater than a serum containing only the vitamins,” explains Dr. Bucay.
The bottom line: While your vitamin C serum does not need to have an unpleasant smell in order to deliver standout results—case in point: the potent, fragrance-free Skin Refiner ($85) from Beauty Stat—opting for a vitamin C serum that’s spiked with ferulic acid will significantly enhance the results you’re looking for, even if it takes a couple of uses to get used to the smell. Whatever it takes to get that glow, right?