Vitamin C & Skincare

By Mark Miller, MD | Jun 30, 2019

Vitamin C (L-Ascorbic acid) is a topical skincare ingredient whose benefits are backed by scientific evidence. It’s primary use in Cosmeceutical skincare is as a powerful antioxidant which means it fights, “free radicals.”  So, what exactly is a free radical and why do we need to fight them?

No, it is not something political – It’s a term used in chemistry to describe an atom or molecule that is highly reactive and in some cases, particularly bad for our health and the health of our skin. Webster’s gives a pretty good definition of a “free radical:"

an especially reactive atom or group of atoms that has one or more unpaired electrons; especially : one that is produced in the body by natural biological processes or introduced from an outside source (as tobacco smoke, toxins, or pollutants) and that can damage cells, proteins, and DNA by altering their chemical structure

We need to fight free radicals because they can damage the DNA of our skin cells. Ingredients called antioxidants are the solution and Vitamin C is an excellent choice in skincare.  Vitamin C is also a proven tyrosinase inhibitor, which means it interferes with the skin’s production of melanin. This can lead to lighter and more even skin tone. Hence, vitamin C is also a popular ingredient for skin lightening and fading freckles and spots. There is also solid research indicating vitamin C can stimulate collagen synthesis. Skin with more collagen will appear younger and more supple. Finally, research also indicates Vitamin C also combat sun (UV) damage to the skin, damage which can cause wrinkles and photoaging.

Stability & Water

Formulating vitamin C in skincare products is difficult due to its lack of stability. When exposed to air, a vitamin C solution will oxidize rendering it less effective and possibly harmful to the skin. The key sign of oxidation in a Vitamin C solution is a yellowish tint, which will darken as the process advances.

A vitamin C solution means that it has been dissolved in water, which is very common in many skincare brands. “Anhydrous” vitamin C formulations are less common and more challenging to formulate into skincare products. These contain high amounts of vitamin C with no water. This helps prevent oxidation while also reducing irritation, as vitamin C solutions can be very acidic.

Anhydrous (water free) vitamin C is more stable, not only in the cosmetic bottle or tube sitting on the shelf, but also on your skin after you apply it. Many water-based vitamin C formulas have other ingredients, such as Ferulic acid, added to them to help stabilize them and delay oxidation during storage. However, they can still oxidize quickly on the skin surface. The other advantage of anhydrous vitamin C is that it’s less irritating. This is the result of not having hydrogen ions generated by acid reacting with water. 


The potency of vitamin C skincare products is an issue not widely understood. Many products have only a token amount of vitamin C in them, perhaps just used as a marketing angle. However, the body of research indicates vitamin C serum
 should have 5% to 
At least 10% 
is preferred by many
to promote collagen synthesis.

 Some might ask, why not 100%? Well, 100% vitamin C would be a white crystalline powder, not a cream or serum one could apply to the skin -- and it would also be very acidic and irritating. If anyone tells you a skincare product is 100% vitamin C, I would be cautious; they might not really understand the chemistry. 


There are 3 types of vitamin C most commonly used in skincare products. The first, L-Ascorbic Acid, is pure vitamin C. Ascorbyl Palmitate is a fat-soluble derivative of vitamin C and is very popular due to its ability to blend with oils and increased stability, which means it resists oxidation better in a skincare formula. It is also less irritating to people with sensitive skin. It has great antioxidant benefits, however it may not be as effective at stimulating collagen. 

The third very common form of vitamin C in skincare products is Magnesuim Ascorbyl Phosphate (MAP). This is a water-soluble derivative of vitamin C that is also less irritating and more stable than L-Ascorbic Acid. MAP appears to have the good potential to boost skin collagen synthesis and be effective in lower concentrations. 


I highly recommend including a high potency vitamin C serum in your skincare regime. Foremost, it is a powerful antioxidant that can prevent the cellular damage caused by free radicals. It may also protect the skin from UV radiation and the damage caused by exposure to the sun. It is a safe and gentle skin brightener, helping reduce melanin and even skin tone. And finally, boosting collagen will lead to younger, healthier skin. A good body of scientific research to date indicates vitamin C can offer all of these benefits.

Here is a list, sorted by cost of some high potency Vitamin C products with different forms of Vitamin C in water based and anyhydrous formulations. 


DS Dermasensa Tri-C Serum            30ml               $60

10% MAP, L-Asorbic Acid & Ascorbyl Palmitate, Anhydrous (water-free)


DS Dermasensa C Super Serum       20ml               $75

20% L-Ascorbic Acid, Anhydrous (water-free)


 Cellex-C High Potency Serum          30ml               $110

10% L-Ascorbic Acid (water-based)


Skinceuticals Serum 2                         30ml                  $119  

20% L-Ascorbic Acid (water-based)


Perricone MD Vitamin C Ester 15      40ml               $130 

15% Ascorbyl Palmitate (water-based)



Mark Miller, MD

Plastic Surgeon

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