Vitamin C is one of the most researched ingredients in skincare — and one of the most misunderstood. Here's what it actually does and how to use it without irritating your skin.
What vitamin C does
- Brightens: helps fade the look of dark spots and post-blemish marks for a more even tone.
- Protects: as an antioxidant, it helps defend skin against pollution and UV stress (under sunscreen, never instead of it).
- Supports collagen: regular use helps skin look firmer and smoother over time.
How to use it
Apply your vitamin C serum in the morning, after cleansing and toning, before moisturizer and SPF. A few drops go a long way. Our Radiance Day Serum With Vitamin C is lightweight and layers cleanly under makeup.
Common mistakes
- Mixing with strong actives in the same step. If you use AHA or retinol, keep them for the evening and vitamin C for the morning.
- Expecting overnight results. Brightening takes 4–8 weeks of consistent use.
- Skipping patch tests. Try a small area first for 2–3 days, especially with sensitive skin.
- Forgetting SPF. Vitamin C works best as sunscreen's teammate.
Who should try it
Anyone dealing with dullness, uneven tone, or dark spots — which is most of us. Start every other morning if your skin is reactive, then build to daily.
Shop the Radiance Day Serum and read more in The 4-Step K-Beauty Routine for Glass Skin.