Under-eye circles can appear for a number of reasons, and vitamin C eye creams may not effectively treat some of them, experts say. But brands often market ingredients such as vitamin C and vitamin K — which consumers recognize — as a catchall for dark circles, according to Roberts-Smith. These skin-brightening ingredients are best for true hyperpigmentation, which is caused by skin inflammation. Inflammation near the eyes can happen for a number of reasons such as repeated exposure to the sun, untreated allergies or rubbing your eyes too aggressively. Some are also predisposed to hyperpigmentation under the eyes based on genetics, and in that case, a vitamin C eye cream may not provide visible results.
Another form of dark circles are known as under-eye shadows, and these appear when the fat that supports under-eye tissue loses volume or shifts. The eye’s thin skin can also invite blood and other fluids to collect near the under-eye area, causing them to look dark or puffy. To address puffy or fatigued under-eyes, Roberts-Smith suggests finding products with caffeine, green tea and ginseng.
The takeaway: Vitamin C and vitamin K can help with true hyperpigmentation, but not necessarily for eye shadows, which may require consultation with a skin-care professional.