Vitamin C: What It Really Does for Your Skin

Vitamin C can be a useful addition to a skincare routine, particularly for uneven tone, dullness and early signs of sun damage. But the formula matters. Two products with “vitamin C” on the label won’t necessarily perform the same way.

What does it actually do?

Vitamin C is needed for normal collagen production. Applied to the skin in an effective formulation, it may help improve fine lines and some signs of sun damage over time. The research is encouraging, although clinical studies are relatively small and results vary between products.^1,2

It is also an antioxidant, meaning it helps neutralise unstable molecules called free radicals that can damage skin cells. UV exposure is one source of these molecules. Vitamin C can complement sunscreen by helping reduce oxidative damage, but it doesn’t replace UV protection.^2,3

For pigmentation, vitamin C can interfere with the processes involved in making melanin, the pigment that gives skin its colour. This may help improve uneven tone, but it won’t reliably clear every dark spot or treat every type of pigmentation on its own.^1,3

Which form should you use?

L-ascorbic acid is the most studied form of topical vitamin C. The challenge is keeping it stable and getting it into the skin.^3,4 Its acidic formulation can also cause stinging or irritation, particularly if your skin is already sensitive.

Derivatives such as sodium ascorbyl phosphate, magnesium ascorbyl phosphate and ascorbyl glucoside can offer better stability and may be easier to tolerate. However, they don’t all have the same evidence behind them, so I wouldn’t describe them as interchangeable with L-ascorbic acid.^1,4

I would look at the complete formulation rather than choosing the highest percentage. A product needs to remain stable, work as intended and be comfortable enough for you to keep using.

Where does it fit in your routine?

Morning is a practical time to use vitamin C, usually after cleansing and before moisturiser and sunscreen. Follow the product instructions and introduce it gradually if your skin is sensitive.

If you have active eczema, a rosacea flare or skin that is already sore and irritated, I would settle that first. Persistent burning or redness is a reason to stop and review the product, not something you need to push through.

You also don’t need to overhaul your routine to make room for it. Get your cleanser, moisturiser and sunscreen right first, then consider whether vitamin C adds something useful.

My view is that vitamin C earns its place when the formulation suits your skin and you have a clear reason for using it. Expect gradual changes rather than an overnight transformation, and don’t judge a product by how much it tingles.

Vitamin C serums we stock

These are the vitamin C products we stock at Cleon. Each one links to its page in our shop.

C E Ferulic Vitamin C Serum → SkinCeuticals · For normal to dry skin. A daytime antioxidant serum.

Phloretin CF Vitamin C Serum → SkinCeuticals · For uneven tone.

Phloretin CF Vitamin C Gel Serum → SkinCeuticals · For normal to oily skin, in a lighter gel.

Silymarin CF Vitamin C Serum for Oily Skin → SkinCeuticals · For oily and blemish-prone skin.

Serum 10 AOX Vitamin C Serum for Sensitive Skin → SkinCeuticals · For sensitive skin, or a gentler start.

Tri Vita C Serum → Dermaceutic · Three forms of vitamin C in one serum.

Antioxidant AOX Vitamin C Eye Gel → SkinCeuticals · For the eye area.

Shop all vitamin C →

References

1. Pullar JM, Carr AC, Vissers MCM. The roles of vitamin C in skin health. Nutrients. 2017;9(8):866. doi:10.3390/nu9080866 Partly funded by Zespri, a kiwifruit company.

2. Al-Niaimi F, Chiang NYZ. Topical vitamin C and the skin: mechanisms of action and clinical applications. J Clin Aesthet Dermatol. 2017;10(7):14–17. PMC5605218

3. Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143–6. doi:10.4103/2229-5178.110593

4. Stamford NPJ. Stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives. J Cosmet Dermatol. 2012;11(4):310–7. doi:10.1111/jocd.12006 Author from Ultraceuticals, a skincare company.