
A cosmeceutical is a product that contains biologically active ingredients which have medicinal benefits.
Examples of basic skin care include moisturisers, sunblock, cleansers and toners.
Examples of cosmeceuticals / prescription grade skin care include Retinoids, Niacinamide, some vitamin C preparations, and hydroquinone.
For a product to be considered a cosmeceutical that has a beneficial physiological effect, the active ingredient must fulfil 4 criteria:
- It should have a known specific biochemical mechanism of action in human skin
- It should be able to penetrate the stratum corneum of the skin
- There should be sufficient concentrations of the active ingredient
- This penetration of the skin should be in a time course consistent with its mechanism of action
There should also be published, peer-reviewed, double-blind, placebo-controlled, statistically significant, clinical trials to substantiate the efficacy claims.
An example of an ingredient that could be considered basic skin care or a cosmeceutical is Vitamin C:
Vitamin C is an antioxidant, enables collagen synthesis, and reduces inflammatory pathways.
Vitamin C is used in skin care products either as BV-OSC, or L’Ascorbic acid.
Some BV-OSC is converted to L’Ascorbic acid after application to the skin.

The most bio-available form of vitamin C is L’Ascorbic acid. This stimulates collagen production, and is water-soluble.
At least 10-15% L-Ascorbic acid is needed for optimum anti-ageing properties.
BV-OSC is oil soluble, so offers hydration and antioxidant protection in the upper layers of skin. However, BV-OSC has to be converted into L’Ascorbic acid before the body can use it to stimulate collagen.
If a product claims to have 15% Vitamin C, but this is BV-OSC rather than L’Ascorbic acid, it will offer antioxidant protection, but may NOT stimulate collagen synthesis.
The amount of this 15% BV-OSC that is converted to L’Ascorbic acid depends on the health, age and skin condition of the person.
The amount converted may not be enough for collagen synthesis.
Therefore, even a skin care product that is “15% vitamin C” may not be optimum for anti-ageing.

There are a huge number of basic skin care products and cosmeceuticals, making various claims about the activity of their ingredients.
It can be difficult to work out which will benefit the skin and which are just expensive creams making bold claims.
Over the next few blog posts, I aim to advise on what to look for and what to avoid when choosing your skin care products J