Vitamin C: can it be used as a deodorant?

The vitamin C, or ascorbic acid, is one of the most extensively studied active ingredients in cosmetics for its ability to neutralise free radicals and stimulate collagen synthesis. It also plays a role in regulating pigmentation thanks to its inhibitory effect on tyrosinase, the enzyme that converts tyrosine into melanin. Moreover, several studies have shown that the vitamin C may be beneficial in reducing skin inflammation. It is most commonly found in derivative forms, such as sodium ascorbyl phosphate or ascorbyl glucoside, because pure ascorbic acid is unstable and its acidity can cause redness, tingling and sometimes irritation in individuals whose skin barrier is compromised.

To date, no scientific data show that vitamin C has a deodorising effect or that it could mitigate unpleasant body odours.

As a reminder, deodorants work through two mechanisms: reducing bacterial proliferation and neutralising odorous molecules produced during the breakdown of sweat. Contrary to popular belief, sweat itself is odourless: it is the bacteria of the axillary microbiome that metabolise the compounds in sweat to form volatile acids responsible for body odour. To counteract this phenomenon, deodorants employ antibacterial agents, such as certain forms of zinc, and absorbents that limit moisture, moist environments favouring the proliferation of micro-organisms. The vitamin C, despite its recognised antioxidant properties, neither interferes with the growth of odour-causing bacteria, nor with the biochemical pathways that lead to the formation of odorous molecules.

Nevertheless, while vitamin C cannot reduce body odour, it could be beneficial in combating underarm hyperpigmentation.

The armpits are indeed areas frequently prone to hyperpigmentation. The skin there is thin and subject to repeated friction — notably from tight clothing or shaving — which induces persistent low-grade inflammation. This inflammation stimulates melanocyte activity through the local release of pro-inflammatory cytokines, promoting increased melanin production. Furthermore, perspiration and the microbiome specific to this area contribute to maintaining an irritated state that further increases the risk of hyperpigmentation.

In this context, the vitamin C could theoretically be of interest, not as a deodorant but as a lightening agent. As mentioned previously, vitamin C has an inhibitory effect on melanin synthesis, together with antioxidant and anti-inflammatory properties, both of which are relevant for addressing hyperpigmentation at an early stage.

Vitamin C therefore does not act on odours, but may reduce underarm hyperpigmentation, making its use potentially relevant in deodorants.

Note : Although the skin-lightening effect of vitamin C has been demonstrated in various clinical trials, none have been specifically conducted on the underarm region, so caution is advised.

• SELANG T. & al. Vitamin C in dermatology. Indian Dermatology Online Journal (2013).

• CHIANG N. & al. Topical vitamin C and the skin: Mechanisms of action and clinical applications. Journal of Clinical and Aesthetic Dermatology (2017).

• LEONARDI G. R. & al. Deodorants and antiperspirants: Identification of new strategies and perspectives to prevent and control malodor and sweat of the body. International Journal of Dermatology (2021).