Vitamin C – The Antioxidant Superhero

There are a lot of “gold standard” ingredient claims within the skincare industry. This is ironic coming from an industry that doesn’t seem to know how to simplify anything enough to offer a “standard” solution. In a complex realm of 10 step regimens, would you be surprised to learn that “gold standard” ingredients also come in different forms for the same ingredient with some being drastically better suited than others?

The Vitamin C Confusion

Vitamin C is a prime example of a “gold standard” ingredient that is all too often oversimplified. The more broad category itself includes several different forms, and those forms do not all behave the same way on the skin. Some are more beneficial than others depending on what you are trying to address, and the formulation itself matters just as much as the form being used.

This is where consumers often get understandably confused. “Vitamin C” is constantly talked about as a must have, but there are plenty of products on the market that would be more appropriately labeled must not touch. I hear all kinds of hesitation from clients when it comes to product recommendations, but none seems to come up quite as often as, “My skin just doesn’t like Vitamin C.”

In reality, that usually tells us something a little more specific. The skin may not have liked that particular form of Vitamin C, or it may not have liked the formulation as a whole. A bad experience with one Vitamin C product does not automatically mean the skin cannot tolerate Vitamin C as a category.

Why is Vitamin C so beneficial for the skin?

Abundant daily environmental factors, such as exposure to UV radiation and pollution, accelerate damage to the skin by creating oxidative stress. This occurs when there is an imbalance of reactive oxygen species, also known as free radicals, and antioxidant defenses.  Vitamin C is one of the most potent antioxidants for the skin. It neutralizes the oxidative stress by a process of electron transfer and/or donation.

Aging itself is a progressive accumulation of damage at a molecular and cellular level as a result of all of these daily insults. As a potent antioxidant, Vitamin C not only works to combat oxidative stress, but also provides much needed support to other elements of healthy skin, such as:

• It helps support the skin’s immune response which has shown to be compromised with regular sun exposure.
• Supports the effectiveness of SPF and protects the skin against burns
• Vitamin C is essential for the production of collagen within the skin
• Vitamin C is known to be the primary replenisher of vitamin E, which similar to vitamin C, is rapidly depleted after UV exposure
• Different forms of Vitamin C have been shown to have effective benefits for lightening and preventing pigmentation

Types of Vitamin C

While there are quite a number of different forms of Vitamin C out there, let’s discuss a few of the more popular ones:

1. Ascorbic Acid
   

   Ascorbic acid, often listed as L ascorbic acid, is the most common water soluble form of Vitamin C and it is also the form most likely to be behind the “my skin just doesn’t like Vitamin C” experience. It is a legitimate, well studied antioxidant, but the issue lies with it is not an easy ingredient to formulate well. Because the molecule is water soluble and charged, it does not pass through the lipid rich skin barrier easily. To improve penetration, traditional water-based ascorbic acid formulas usually need to be pushed into a very low pH range, often below 3.5, which is noticeably more acidic than the skin’s normal surface environment. That low pH can be a problem for sensitive, inflamed, acne prone, or barrier compromised skin, especially when brands pair it with higher percentages and market the irritation as “activity.”

   The other major issue is stability. Ascorbic acid is highly vulnerable to oxidation, especially with repeated exposure to air, light, heat, and poor packaging. Once a formula starts to oxidize, the product is no longer behaving the way it was intended to behave, and a serum turning deep yellow, orange, or brown is usually a sign that it should no longer be treated as an effective antioxidant product. That does not inherently mean ascorbic acid is a bad ingredient but rather a high maintenance and demanding one. The best versions need thoughtful pH control, stabilization, compatible antioxidants, and packaging that protects the formula from unnecessary exposure and with other solutions available and even more being created, I'm not convinced it's worth the headache.

   Thankfully, formulation science has moved beyond the basic “water, ascorbic acid, low pH, hope for the best” approach. We now have more sophisticated delivery systems and stabilized ascorbic acid complexes that can improve performance and reduce some of the traditional limitations. The catch is that those systems are more expensive to formulate, so this is one of those categories where the $30 impulse buy can be very different from a thoughtful and intentionally built formula.

   
   
   
2. Tetrahexyldecyl Ascorbate
   This is an oil soluble Vitamin C ester. The skin is made up of a good deal of lipids and this oil soluble form allows this ingredient to penetrate without being pH dependent. It is highly stable, gentle, and ultimately much more suitable for those who may be hesitant where Vitamin C is concerned.
   
   It combats oxidative stress by helping to prevent oxidation within your own skin’s lipids. This form of Vitamin C packs a punch against hyperpigmentation. It’s the form of Vitamin C you want to turn to if that is your primary issue.  AnteAGE has leaned into the powerful effects of this Vitamin C derivative including a high therapeutic concentration in both their Accelerator and their Brightener.
    
   
3. Sodium Ascorbyl Phosphate
   A water soluble yet highly stable form of Vitamin C, Sodium Ascorbyl Phosphate is also not pH dependent. This makes it gentle and beneficial even for sensitive skin.
   
   Sodium Ascorbyl Phosphate provides all of the benefits Vitamin C is known for but studies have shown a substantial improvement on subjects with acne when using this ingredient. If you are looking for a Vitamin C product and acne is your concern, this ingredient is what you will want to lean towards.  A powerhouse Vitamin C Serum for both acne prone skin and aging skin is Mikura's Oligo C Antioxidant Peptide Serum.
   
   
4. Magnesium Ascorbyl Phosphate
   Another water-soluble form of Vitamin C, Magnesium Ascorbyl Phosphate also has what Ascorbic Acid lacks: stability without a pH dependency. It is much gentler on skin and still maintains its efficacy in lower concentrations. While it is slightly less effective in free radical reduction than Ascorbic Acid, it is much more hydrating.

1. 3 O Ethyl Ascorbic Acid
   A stabilized derivative of Vitamin C that was developed to address some of the challenges associated with pure L ascorbic acid, particularly that instability and rapid oxidation mentioned earlier. Once applied to the skin, it can be converted into active vitamin C, allowing it to support antioxidant activity, brighten uneven skin tone, and help reduce the appearance of discoloration. It is generally well tolerated even with sensitive skin types and  functions across a broader pH range than pure ascorbic acid.  Our favorite products containing this form are again the Mikura Oligo C which combines this form with Sodium Ascorbyl Phosphate and the Hale and Hush Rare C Serum which provides this form in a very gentle sensitive skin forward formulation. 

About the Author:

Dru Pattan is a Licensed Esthetician who specializes in acne while taking a skin healthy approach to sustainably healthy skin known as Corneotherapy. She believes that we don't need to beat the skin into submission to make it comply. By monitoring the skin's needs and offering nourishment we are able to heal common ailments which can often seem lifelong and defeating.

Dru has been licensed since 2014 and has spent the majority of that time relentlessly hunting down advanced education within the industry. When she herself is not studying, she is offering education and support to clients and other professionals within the industry.