How To Layer Them Correctly
As always, the order of application matters. Your Vitamin C serum should always be applied first, directly onto cleansed skin, and allow for it to fully absorb before SPF is layered on top. This ensures the antioxidant is positioned within the skin where it can intercept free radicals, while SPF sits on the surface to filter incoming UV rays.
Avoid formulations that combine both ingredients in a single product, the stability of Vitamin C can be compromised when mixed directly with SPF filters, ultimately reducing the efficacy of both5.
The Long-Term Payoff
Prevention is the most powerful tool against anti-aging. Consistent, daily use of Vitamin C and broad-spectrum SPF can help to improve skin tone and texture, as well as reduce fine lines.
Footnotes
1. Diffey, B.L. (2001). When should sunscreen be reapplied? Journal of the American Academy of Dermatology, 45(6), 882–885.
2. Lin, F.H., Lin, J.Y., Gupta, R.D., et al. (2003). Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin. Journal of Investigative Dermatology, 125(4), 826–832.
3. Pinnell, S.R. (2003). Cutaneous photodamage, oxidative stress, and topical antioxidant protection. Journal of the American Academy of Dermatology, 48(1), 1–19.
4. Burke, K.E. (2007). Interaction of vitamins C and E as better cosmeceuticals. Dermatologic Therapy, 20(5), 314–321.
5. Telang, P.S. (2013). Vitamin C in dermatology. Indian Dermatology Online Journal, 4(2), 143–146.