Use it in the morning on clean, dry skin, a few drops only, then moisturiser, then sunscreen. Keep the bottle away from heat and sunlight, and replace it if it turns dark yellow or brown. Give it up to 12 weeks before judging.
Step by step
- Cleanse. Wash your face and pat it dry.
- Toner, if you use one. Lightest products go on first.
- Vitamin C serum. A few drops, spread over face and neck. Follow the amount on your product’s label.
- Moisturiser. Dermatologists suggest layering moisturiser over the serum.
- Sunscreen, every morning. Make it the last step before makeup.
Use it once a day to start. Putting on more doesn’t give faster results, and overdoing it can irritate skin.
Morning or night?
Most dermatologists prefer the morning, because vitamin C is an antioxidant that helps against free-radical damage from UV light and works alongside your sunscreen. Night use is fine too, especially if your serum irritates when combined with other morning products.
One important point: vitamin C is not a sunscreen. It doesn’t absorb UVA or UVB light, so you still need SPF every day. In India’s sun, that matters more than any serum.
Choosing a serum: what the label should tell you
- The form. L-ascorbic acid is the most effective form on skin but the least stable. Derivatives such as ascorbyl phosphate are more stable but penetrate skin less well.
- The strength. Studies that found less wrinkling and roughness used 3–10% vitamin C for at least 12 weeks. Lab research found absorption peaked around 20%; going higher didn’t help.
- The packaging. Air, heat and light slowly break vitamin C down. Dark or opaque bottles and airless pumps protect it better than clear droppers.
Storing it in Indian heat
Keep it at room temperature, out of direct sunlight, with the cap closed. Don’t leave it on a sunny windowsill or in a hot car. If the serum turns dark yellow, orange or brown, it has oxidised and is past its best. Many practitioners suggest replacing an open bottle after about three months.
What not to mix it with
Avoid applying it at the same time as retinol or retinoids, benzoyl peroxide, or AHA/BHA acids. They can irritate together and work best at different pH levels. An easy split: vitamin C in the morning, retinol or acids at night, on different days if your skin is sensitive.
Side effects
A light tingle is common at first. Mild redness, dryness or irritation can happen and usually settles. Try it on a small area first if your skin reacts easily.
Stop and see a doctor if you get a rash, itching, hives, or any swelling of the face, lips or throat. Those are signs of an allergic reaction.
Where Nu Skin’s Vitamin C Serum fits
Nu Skin sells a Vitamin C Serum in India for ₹2,400 (nuskin.com/in, checked 22 October 2026). We haven’t reviewed it yet. Before buying any serum, check the ingredient list for the form of vitamin C and the packaging, using the points above.
How we wrote this: this guide is based on the sources listed below, including Oregon State University’s Linus Pauling Institute and Cleveland Clinic. It isn’t medical advice. If you have a skin condition, are pregnant, or are using prescription treatments, ask a doctor first.
Questions
Can I use vitamin C serum every day?
Yes, once a day is the usual starting point. Use small amounts; more isn’t better and can irritate.
How long until I see results?
Give it up to 12 weeks. The studies that found improvements in wrinkles and roughness ran for at least 12 weeks.
Does vitamin C serum replace sunscreen?
No. Vitamin C doesn’t absorb UVA or UVB light. Use sunscreen every morning as your last step.
My serum turned brown. Is it still okay?
It has oxidised and lost effectiveness. Replace it, and store the next bottle away from heat and light.