When I first met Sunday Riley’s vitamin C serum, C.E.O. Rapid Flash Brightening Serum, I had just exited an abusive relationship with a product that left me the worst acne scarring of my life. I had a ton of new hyperpigmentation (dark spots from dark times) and, because I had scaled back on all other skincare to coax the healing process along, my complexion was looking seriously dull and splotchy. I needed something that would be gentle on my battered skin, powerful enough to lift pigmentation, and fast-working.
To buy: $64 with code "BIRTHDAY" (marked down from $85); dermstore.com
I had already heard a lot of great things about this product, mainly in the form of recommendations from beauty insiders, so my expectations were high. After only a day or two of using the vitamin C serum, the smattering of brown acne marks along my cheeks was already beginning to fade. My lackluster skin beneath the unsightly spots was taking on a more uniform tone, and within a month I was no longer using foundation, just spot concealing the ever-vanishing dark marks.
Vitamin C is well known for its brightening and collagen-boosting abilities, and this serum is formulated with THD ascorbate, a less common form of the antioxidant. THD is just as effective as vitamin C’s more popular forms, but is more shelf-stable, which means no fussing over refrigeration or worrying about it expiring before you’ve emptied the bottle, and "is quickly absorbed into skin," according to New York City dermatologist Debra Jaliman, MD. It also means a lowered risk of irritation, which was exactly what my skin needed in its fragile state.
Pair the major benefits of vitamin C with gently exfoliating glycolic acid, ultra-hydrating squalane, and other soothing agents—all ingredients found in this one product—and my face was finally looking fresh again.
It’s luxuriously creamy, gently fragrant, and so effective. The only thing I don’t love about it is the (admittedly worthwhile) price tag. Lucky for all of us, C.E.O. plus a ton of other Sunday Riley products—which rarely go on sale—are marked down 25% at Dermstore’s anniversary sale with promo code BIRTHDAY. Until August 19 you can score my favorite vitamin C serum, which usually costs $85, for a smooth $64.