• Marsha

DERMATOLOGICAL BENEFITS OF TOPICAL VITAMIN C


Vitamin C is well-known to be a potent anti-oxidant, used by many dermatologists to topically treat the signs of photoageing. Yes, it is true that vitamin C from food is indispensable for our health, but it has been suggested that the bioavailability of Vitamin C in the skin is inadequate when taken orally. As a result, the use of topical vitamin C is favoured in the practice of dermatology.


The biologically active form of Vitamin C is L-ascorbic acid (LAA) and while there exists many, more stable, LAA derivatives out there, I personally only trust LAA as an ingredient for topical application. But, note that LAA is extremely unstable as it is sensitive to light, air, and temperature. So formulation is everything when it comes to Vitamin C. Another important thing to note is that you need at least 8% LAA to be biologically significant. So, if you see products marketed as a vitamin C product but no % is mentioned or the LAA is listed somewhere at the bottom of the ingredients list, then I suggest you find something else! I will give my recommendations below!


So, what are the benefits of Vitamin C?


1. Antioxidant: Vitamin C protects the skin against oxidative damage by donating electrons to neutralize free radicals.


2. Photoprotection: Vitamin C, especially when combined with Vitamin E (Vitamin E increases the action of Vitamin C by 4x), can protect our skin from UVA and UVB damage, including redness, sunburn cell formation, as well as reducing cell death. Furthermore, when Vitamin C and E are combined with Ferulic acid, this combo increases the efficacy of Vitamin C by 8X!!!


3. Collagen biosynthesis: Vitamin C is essential for the synthesis of collagen - so definitely a great anti aging skincare ingredient. It has a direct effect on the transcription of procollagen mRNA.


4. De-pigmenting agent: Vitamin C interacts with copper ions at the tyrosinase (enzyme that produces melanin) active site, thereby inhibiting melanogenesis. However, because of its unstable chemical nature, it is often combined with other depigmenting agents like soy or licorice for a better depigmenting effect.


5. Anti-inflammatory: Though not thoroughly explored, Vitamin C also has a potential anti-inflammatory activity, and can thus be used by those suffering from acne or rosacea. It can promote wound healing and post-inflammatory hyperpigmentation.


There are so many benefits of topical Vitamin C. However, as I mentioned, it is highly unstable and exposure to light can trigger oxidation to Dehydro Ascorbic Acid (DHAA), giving it its yellow colour. The stability of vitamin C is controlled by maintaining a pH of lower than 3.5. This is why I cannot stress enough that formulation is everything when it comes to Vitamin C and not all preparations out there are physiologically effective.


Another question I get a lot is whether a higher concentration of vitamin C is always more effective, in other words "the more the better". The answer is yes, but only up to 20%. You're not going to get much more benefit by using vitamin C higher than 20%. So a good rule is to stick between 8-20%, depending on what your skin needs. Bear in mind that this concentration works for LAA. If you're using a derivative, this may tell a different story as these derivatives need to be converted to LAA first in order to have any effect in your skin. So for example, using 20% derivative is unlikely to give you 20% LAA (will be much lower).


Given the reasons above, I prefer Vitamin C products that are formulated with other ingredients, e.g. Vitamin E and/or Ferulic Acid. Here are my top Vitamin C serum picks:



Courtesy of Brand


SkinCeuticals

C E Ferulic


Courtesy of Brand


Paula's Choice

C15 Super Booster


Courtesy of Brand


Tatcha

Violet C Brightening Serum


Courtesy of Brand


Kiehl's

Powerful-Strength Line-Reducing Concentrate



Till next time,


The Skin Press



Reference(s):

Telang. (2013). doi: 10.4103/2229-5178.110593

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