Vitamin C Serum: What Can it do for my skin

Vitamin C is one of the most researched antioxidants in skincare. It is present in high concentrations in normal skin, protects against ultraviolet-induced pigmentation, and helps regulate collagen production [1].

What the research shows

A 2023 systematic review searched Medline, CENTRAL and Scopus for randomised controlled trials of topical vitamin C in photodamage and melasma, and included seven trials covering 139 volunteers. Trials that measured skin topography found treated skin appeared smoother and less wrinkled, supported by biopsy data, and objective assessments showed significant lightening of pigmentation [1].

Two honest caveats from that same review: long-term use may be needed before changes are noticeable, and the ideal concentration has not yet been established [1]. Interestingly, hydration improved equally in the vitamin C and placebo groups, so vitamin C is not primarily a hydrating ingredient [1].

Mechanistically, vitamin C reduces oxidative stress and promotes collagen gene expression and maturation, which is the basis for its use as an anti-ageing active [2].

How to use a vitamin C serum

Use it in the morning, where its antioxidant activity supports the skin against daily environmental stress.

Apply after cleansing and before moisturiser. Use 1 to 2 pumps, pressed gently into the face, neck and décolletage. Let it absorb, then moisturise and finish with sunscreen.

If your skin is sensitive or this is your first vitamin C, start every second day and build to daily as tolerated.

The different forms of vitamin C

Not all vitamin C is the same. The forms differ in stability, strength and suitability for different skin types [2].

L-ascorbic acid. The pure, active form and the one used in most of the clinical trials above [1]. Effective for brightening, collagen support and pigmentation, but less stable and more likely to irritate sensitive skin.

Sodium ascorbyl phosphate (SAP). A gentler, more stable derivative suited to sensitive and acne-prone skin, with antioxidant and brightening benefits and lower irritation risk.

Magnesium ascorbyl phosphate (MAP). Water-soluble and stable, supporting hydration, tone and barrier function. A good option for dry or sensitive skin.

Ascorbyl glucoside. A stable derivative that converts to active vitamin C in the skin, offering gradual brightening with good tolerance.

Derivatives are generally more stable and better tolerated, but the strongest clinical evidence sits with L-ascorbic acid, so there is a genuine trade-off between tolerability and evidence base [1][2].

What to pair it with

Vitamin C works in the morning; retinoids work at night [3]. Sunscreen is non-negotiable alongside both, since UV exposure is the dominant driver of visible facial ageing [3]. In a 2025 network meta-analysis of topical anti-ageing treatments, retinoids ranked highest for fine wrinkles while different agents suited different concerns, which is a good argument for a combined routine rather than a single hero product [4].

Niacinamide pairs well with vitamin C and supports the barrier [5].

Choosing the right vitamin C for your skin

The best serum depends on your skin type, concerns and tolerance. Stronger formulations may work faster but need careful introduction, while gentler derivatives deliver steady benefits with less irritation.

At Oceania Wellness we recommend choosing vitamin C as part of a personalised routine, so you get results without compromising your skin barrier. Book a consultation if you would like help deciding.

References

1. Correia, G., & Magina, S. (2023). Efficacy of topical vitamin C in melasma and photoaging: A systematic review. Journal of Cosmetic Dermatology, 22(7), 1938–1945. https://doi.org/10.1111/jocd.15748
2. Boo, Y. C. (2022). Ascorbic acid (vitamin C) as a cosmeceutical to increase dermal collagen for skin antiaging purposes: Emerging combination therapies. Antioxidants, 11(9), 1663. https://doi.org/10.3390/antiox11091663
3. Quan, T. (2023). Human skin aging and the anti-aging properties of retinol. Biomolecules, 13(11), 1614. https://doi.org/10.3390/biom13111614
4. Lin, L., Chen, X., Liu, C., Wang, Q., Lian, W., Xu, X., Guo, Y., Zhong, H., Zhong, J., Zhao, N., Cheng, W., Shu, P., & Xu, Z. (2025). Comparative efficacy of topical interventions for facial photoaging: A network meta-analysis. Scientific Reports, 15. https://doi.org/10.1038/s41598-025-12597-0
5. Crespi, O., Rosset, F., Pala, V., Sarda, C., Accorinti, M., Quaglino, P., & Ribero, S. (2025). Cosmeceuticals for anti-aging: Mechanisms, clinical evidence, and regulatory insights—A comprehensive review. Cosmetics, 12(5), 209. https://doi.org/10.3390/cosmetics12050209

This article is general information about skincare ingredients and is not personal medical advice. If you have a specific skin concern, please speak with your GP, dermatologist or one of our therapists.