Written By: Dr. Alexandra Mayer
Vitamin C is often touted as a must have ingredient in skincare. With its long list of benefits, it’s easy to understand why! This powerful antioxidant has been shown to brighten the skin, smooth wrinkles, promote collagen production, diminish the appearance of scars, and protect against harmful UV damage (when used with the proper sunscreen).
Navigating the world of cosmeceuticals can be daunting; The possibilities are endless as every new vitamin C skincare product brought into the market is “the next best thing.” As a consumer, figuring out how to get the most bang for your buck and benefit for your skin is very important. So how do you know what to look for in a Vitamin C? How can you know which form of Vitamin C is best? Don’t fret! This article is your go-to guide for understanding Vitamin-C formulations and finding the right form for your skincare regimen.
L- Ascorbic Acid: The OG Vitamin C
Many doctors and skincare brands tout L-ascorbic acid as “the holy grail of Vitamin C in skincare.” It’s true, L-ascorbic acid is the form of vitamin C naturally found in the skin. However, that’s not the whole picture. L-ascorbic acid in the form of topical formulations comes with its own list of challenges to properly transfer it from the bottle into the dermis of your skin.
L-ascorbic acid is a potent antioxidant, meaning it readily donates an electron to free radicals to neutralize them. This readiness to donate an electron makes it highly efficient at its job. However, it also makes it a notoriously unstable molecule. L-ascorbic acid is oxidized very easily when exposed to light and heat. Thus, most L-ascorbic acid formulas are stored in amber bottles and have added ferulic acid to increase stability. This is also why Vitamin C serums need to be purchased with expedited shipping, especially during Arizona summers (and be mindful of where you are ordering your Vitamin C serums- who knows how long they’ve been sitting in hot Amazon warehouses?)!!
On top of being extremely/particularly unstable, L-ascorbic acid is difficult to absorb through the epidermis (the upper layer of your skin) into the dermis where collagen is made. This is why vitamin C must be kept at a pH of 3.5 or less. This pH will enhance the formula’s ability to penetrate deep to the dermis, which is where you want it. However, it makes Vitamin-C difficult to formulate and difficult to use with other products. For example, retinoids often have a pH of 5-6. This means that the pH of your retinol cream if used at the same time as your Vitamin C will basically cancel each other out.
Second Generation L-Ascorbic Acid
Typically, you will find that a majority of Vitamin C serums have L-ascorbic acid as their only active ingredient. These serums are often formulated with added Vitamin E and ferulic acid to increase absorption and efficacy. Because of its finicky nature, first generation L-ascorbic acid does not do well when formulated with other ingredients, such as Vitamin A or peptides. As if that isn’t enough, L-ascorbic acid is water soluble, meaning that it can only be formulated in water bases. This is why it’s rare to find cream bases with L-ascorbic acid as an active ingredient. If you want a moisturizing Vitamin C, consider yourself out of luck with L-ascorbic acid, since the molecular structure just will not allow for lipid-based formulations.
Advancements in Vitamin C formulation, however, has led to the creation of second-generation Vitamin C products. These products have a carbohydrate molecule attached to one of the carbons in the ring. This adjustment in molecular structure means that this form of vitamin C is significantly more stable and can easily be converted back to L-ascorbic acid once it penetrates into the skin. It also has a less sensitive pH, allowing it to be formulated with other active ingredients. This second-generation form of L-ascorbic acid is still water-soluble and is used in serum-style formulations.
Our favorite second-generation L-ascorbic acid product is the Super Serum. Its light and non-tacky application (because no-ferulic acid is needed) has shown results of: skin brightening, scar reduction, and improvement in fine lines. For skin inflammation and redness, we also love the Pro-Heal Serum, which combines the benefits of Vitamin-C and Vitamin-A for a noticeable anti-inflammatory effect.
Tetrahexyldecyl Ascorbate: The Actual “Next Best Thing”
Tetrahexyldecyl Ascorbate is one of the best forms of second-generation Vitamin C. Studies show that this form of Vitamin C can penetrate up to 5x deeper into the dermis than L-ascorbic acid. This means that formulations with 10% tetrahexyldecyl ascorbate will act more like a 20% l-ascorbic acid formula without the irritation that can come from such a high concentration. Tetrahexyldecyl Ascorbate is lipid soluble and thrives at a higher pH (5-6), meaning this form of vitamin C can be formulated into a cream base AND can be layered with other products without losing its efficacy!
Tetrahexyldecyl ascorbate is a particularly great vitamin C option for patients with sensitive skin or for those looking to boost collagen production and reduce fine lines and wrinkles. Our Ethos brand Vibrant-C uses Tetrahexyldecyl Ascorbate formulated into a light cream base! It’s perfect for layering with our Restorative Cream for the ultimate anti-aging duo.
So which form of Vitamin C is right for me?
We understand that the world of Vitamin C can be extensive. Check out this simplified chart below to compare which formulation may be best for your individualized skin goals!
Vitamin C can be one of the most beneficial ingredients to add to your skincare, as it has the potential to dramatically brighten skin, smooth wrinkles, boost collagen, minimize scars, and offer additional protection against UV rays. However, be wary of cheap Vitamin C products, as they may not have the ingredients or technology to actually penetrate the skin and achieve the results you seek. It pays to invest in your skincare and get quality products with actual effective benefits and noticeable results.