Vitamin C is an essential nutrient, and cannot be synthesized by the human body. It must be consumed in food and is the most abundant antioxidant in human skin.

The active form of Vitamin C in the skin is Ascorbic acid. When applied to the skin in the right formulation, ascorbic acid it is reported to have effects on:

• collagen synthesis (antiageing)

  • ascorbic acid is needed to convert pro-collagen to collagen

• pigmentation

  • suppresses melanin formation via an action on quinone

  • reduces tyrosinase activity

• anti-inflammatory and antioxidant actions

  • acts synergistically to regenerate Vitamin E (tocopherol) and reduce oxidative stress

So why isn’t everyone using Vitamin C and why do Dr Alice Rudd and Skindepth Dermatology not routinely recommend it?

Ascorbic acid is that is very unstable and oxidizes when exposed to air and light, pollution and ozone. So even though the benefits are theoretically there, by the time it hits your skin, the activity may have been lost (despite what the marketing tells you). Additionally formulations of vitamin C that allow stability may penetrate the skin better but are not as potent nor effective once in the skin.

It has been found that in addition to ascorbic acid being difficult to formulate, it is not very effective when used as mono therapy. Which is why when patients ask us ‘which vitamin C should I use’ it really is not that easy. Dr Alice Rudd would always recommend combing the vitamin C with other ingredients, depending on what you can it to achieve in your skin. For example, for pigmentation you are best picking a product that has other tyrosinase inhibitors in it (kojic acid, hydroquinone etc). If you want it for anti ageing then combine with a retinol or vitamin A containing serum.

And finally Vitamin C being an acid is notoriously irritating on sensitive skin. So best avoided in those with rosacea, dry skin or sensitive skin. We see it commonly causing redness in these skin types. Some sensitive skin types will tolerate Vitamin C if formulated with other calming ingredients, or in slow release precursor forms.

So the upshot is Vitamin C is amazing in theory but the reality is is quite restrictive and most of the time is either not doing much in the skin unless the Vitamin C is formulated properly, or may be irritating and worsen some sensitive skin types. Dr Rudd’s advice? Have a proper assessment by a professional who knows skin to determine what the best option is for your skin.