Skincare, Aging & Vitamin C

Let’s talk vitamin C for your skin - the good and the bad.

Vitamin C is one of the most powerful antioxidants in your skin! There are MANY different forms of vitamin C but the most bioactive form that has the most evidence to support its use in skincare is Ascorbic Acid (or L-Ascorbic Acid).

While many of us might think that citrus fruits are the highest source of vitamin C, they actually are not. In 100 grams of oranges, there are only 53mg of Vitamin C but there’s 120mg in the same amount of kale and 147mg in bell peppers. For the sake of this post, let’s focus on TOPICAL application of vitamin C in skincare products.

How is vitamin C (ascorbic acid) beneficial for the skin?

supports collagen formation
stabilizes collagen fibers
decreases collagen degradation
protects against photo-aging
prevents UV damage from the sun
scavenges free radicals from environmental pollutants
decreases melanin formation (therefore, reduces hyperpigmentation or dark spots)

The GOOD:

In theory, vitamin C (ascorbic acid) can improve sun damaged skin and help the skin handle pollution or UV stressors by scavenging free radicals. Since it is already a component within our skin and gets depleted with aging and UV damage, applying vitamin C topically *may* help to mop up some of the free radicals caused by sun (or UV) exposure if it gets through your sunscreen. Sunscreen should ideally block out the damaging UV rays, but anything that gets through can be managed by your skin’s vitamin C. Since vitamin C is a component of collagen, there is data suggesting that it can have an impact on wrinkling and aging by boosting collagen production in the deeper layers of the skin. Ascorbic acid (recall, it is the most bioactive form of vitamin C) can inhibit the tyrosinase enzyme which can be useful in minimizing dark spots and hyperpigmentation.

The BAD:

In topical skincare products, it is very challenging to formulate a product that will have a true beneficial impact on your skin. There are countless “vitamin C” products on the market, but none have the rigorous clinical data that prescription grade products have to really show that the vitamin C is still active and stable once it makes its way in your serum or moisturizer. This doesn’t mean you shouldn’t use a vitamin C product if you enjoy it and you notice a difference. You do you! For the sake of this post, I’m just presenting the facts that we have to date.

To begin, vitamin C is a hydrophilic (water loving) molecule and our skin's stratum corneum is lipophilic, which makes it challenging for a vitamin C product to actually penetrate the tough skin barrier when applied topically. Vitamin C is also extremely unstable when exposed to air and light! So if your bottle or jar of serum or moisturizer is opened day after day and exposed to the light and air in your bathroom, it is rapidly degrading each time you open it. For these reasons, it’s difficult for skincare companies to formulate a product that can actually get INTO your skin and still be active when it gets there.

BUT… it is not all doom and gloom with topical vitamin C!

There is one product that I am aware of that has robust scientific evidence to support the use of topical vitamin C. This specific product has a patented formula that contains vitamin C stabilizing components that are shown to aid in vitamin C skin penetration. Without disclosing the name of this product (if you’re a patient, ask me at your next appointment), here is the criteria that helps to stabilize topical vitamin C and aid with skin penetration:

Ensuring the product is at a pH of 3.5 and concentration of 10-20% (anything higher can increase skin irritation)
Adding ferulic acid to the ingredient list to help prevent degradation of vitamin C
Adding other antioxidants to the formula (like vitamin E tocopherols) to further stabilize the vitamin C

In summary, if you are enjoying your skincare regimen and YOU notice a difference, then that’s all that matters. Again, I always want to reiterate that other products might be useful, but the science isn’t there yet. Remember that the most bioactive evidence based form of topical vitamin C is L-Ascorbic Acid and the other forms we don’t yet have data for their use. Vitamin C can be degraded from other skincare products, so check with your healthcare provider to ensure your skincare products aren’t interacting with one another. If you have any questions, please don’t hesitate to reach out!

References:

PMID: 10522500

PMID: 18310938

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PMID: 17268089

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PMID: 18045356