Can you use vitamin C serum at night?

Should you use vitamin C serum during the day or at night?

Choose morning if you want vitamin C alongside your daytime sun protection. Vitamin C is an antioxidant: it helps neutralize free radicals, unstable molecules that damage skin cells. Sunlight and pollution contribute to those molecules. Vitamin C does not absorb ultraviolet light the way sunscreen does, so the two have different jobs.23

If you choose nighttime application, still use sunscreen during the day. Choose broad spectrum protection, which covers UVA and UVB rays, with SPF 30 or higher and water resistance. Apply sunscreen after your other skincare products and before makeup, 15 minutes before going outdoors. Vitamin C does not replace sunscreen or protective clothing.245

How do you use vitamin C serum on your face at night?

Before the first facial application, test a small amount on your inner forearm twice daily for four to five days. If the area stays free of redness, itching and other reactions, you can apply the product to your face. Check the full ingredient list first, particularly if you have a known sensitivity or allergy.26

1. 1Wash your face with a gentle cleanser. Remove makeup before bed, and avoid scrubbing.
2. 2Apply vitamin C serum after cleansing and after toner if you already use one. A few drops can cover the face and neck; follow your product's directions for the amount.
3. 3Apply moisturizer after the serum.

Start every other night and increase to nightly use if tolerated. Vitamin C can be used daily, but applying more than directed can cause problems rather than improve results. Introduce one new treatment product at a time so you are not starting several potentially irritating products together.26

What if you already use retinol at night?

A straightforward routine puts vitamin C in the morning and retinol at night, with moisturizer in both routines. That gives each product its own place without needing to layer them together. A routine built around your main concern needs products that complement each other, not several bottles auditioning for the same job. Check whether your moisturizer already contains an active ingredient you use separately before doubling up.5

Which serum should you choose?

For an ascorbic acid serum, look for a concentration of 10% to 20%. Sensitive skin should start at the lower end; concentrations above 20% raise the risk of irritation. Different vitamin C forms and formulations have different strengths and effects, so percentages alone do not make every serum equivalent.12

Formula stability matters because vitamin C can break down with exposure to oxygen and light, and poorly formulated products can penetrate skin inadequately. An opaque container protects the formula from light, even if it gives the serum fewer opportunities to pose for the bathroom shelf. Keep the serum away from heat and sunlight.157

What should you expect?

Vitamin C can improve fine lines and skin texture and help fade dark spots. Expect about three months of regular use to see a noticeable difference, not an overnight transformation. Continue using the serum if you want to maintain its benefits; improvements in pigmentation can fade after stopping.12

Dryness, itching and redness are possible side effects. Stop an irritating serum rather than pushing through burning or stinging. If discomfort or irritation is substantial, stop using vitamin C and contact your doctor. For a prescribed product that stings or burns, ask your dermatologist before stopping it.126