All About Vitamin C (+ Its Many Forms)

Vitamin C is essentially the prom queen of skincare ingredients—it wins every popularity contest for its magical multitasking abilities. 

“Vitamin C has a lot of roles in the skin,” says Dr. Dan Belkin, MD, board-certified dermatologist at New York Dermatology Group. “First, it is an essential component of enzymes that build collagen. Second, it's the most important water-soluble antioxidant in the skin. (Antioxidants neutralize reactive oxygen species which are formed under cellular stress such as UV radiation and cause local damage and aging of cells). 

“It increases sun protection when included with vitamin E (the most important lipid-soluble antioxidant in the skin). Vitamin C is also a skin brightener, inhibiting melanin production that can cause spots of hyperpigmentation. All these effects, as well as its ability to be delivered easily, make it a beloved ingredient in skincare.”

Jacob Tomás del Rosario, Senior Manager of Field Sales + Education at Youth To The People, concurs. 

“Vitamin C is so loved by so many people because of its amazing ability to address multiple skin concerns,” del Rosario says, adding that it fights free radicals and helps smooth fine lines and wrinkles. The superstar antioxidant, found in the 15% Vitamin C + Clean Caffeine Energy Serum, also balances and evens tone, leaving the skin brighter and more luminous, supple, and smooth.

There is a broad range of types of vitamin C out there, but one thing they have in common is they are all derived from ascorbic acid. 

“Ascorbic acid is pure vitamin C,” says Dr. Belkin. “All the forms of vitamin C, when properly formulated, break down into ascorbic acid, which is what has activity in the skin. It is combined with different molecules typically to enhance stability, as vitamin C is notoriously unstable in formulation (exposure to UV light or air renders ascorbic acid inactive).” 

Still, each form of vitamin C is unique, with its own perks to prove it. 

“Vitamin Cs are different because they all don't perform in the same way,” del Rosario says. “Though they come from the same original source as mentioned before, innovations in chemistry have allowed for the creation of derivatives of that granddaddy of vitamin C that are stabilized and resistant to volatilities when exposed to the outside world. Though it takes a little more work for the skin to convert a derivative of ascorbic acid into what we know as ascorbic acid in the skin, you do not have the same volatilities to light or to air, or even to time in general. Derivatives of vitamin C are not actively working within the packaging, but once introduced to the skin, your body’s natural chemistry converts a derivative, and its chemical structure breaks down into what your skin knows and loves as ascorbic acid. Simply put, the experience is more consistent with your derivatives, and the formula is in turn more powerful. This is especially vital when that product is dependent on vitamin C for performance.”

“Also,” del Rosario continues, “These formulas can be designed to work immediately or at a delay that makes the formula more beneficial to deeper layers of tissue, or alternatively work on the surface as it absorbs—or my favorite, both.”

Get to know each type of vitamin C:

Ascorbic Acid / L-Ascorbic Acid 

This is pure vitamin C and excellent when packaged intentionally. 

“For example, it’s best in an airtight container if in a liquid formula or without a pump to avoid prolonged exposure to air/oxygenation, in opaque packaging or tinted glass to mitigate UV exposure, and when used in a timely manner once opened,” del Rosario says. 

Ethyl Ascorbic Acid

“This is a next-generation vitamin C derivative, best known for its exceptional collagen boosting properties,” del Rosario says. “It’s non-irritating and both water- and oil-soluble for penetration through all layers of the skin.” Its perks go from the skin’s surface to its internal layers. 

Tetrahexyl Decyl Ascorbate (or THD Ascorbate)

“THD Ascorbate is an oil-soluble form of vitamin C known for being able to penetrate the skin the fastest and deepest of any form,” del Rosario says. “This is the very first synthesized vitamin C specifically designed for use in topical skincare, and is up to 50 times more potent than ascorbic acid alone.” 

Magnesium Ascorbyl Phosphate

“This water-soluble vitamin C is chelated for stabilization and to preserve its efficacy,” del Rosario says. “The process of chelation stabilizes ions, preventing them from chemically reacting with any other substances while in the bottle. This ensures speedy delivery of both stable and potent vitamin C to the skin at every application.”

Sodium Ascorbyl Phosphate: “Water soluble and derived from salt, this is less potent than traditional L-ascorbic acid, but makes it for those who have experienced sensitivities to vitamin C and prefer vitamin C as a day and night treatment,” del Rosario says.

Ascorbyl Palmitate

This is a vitamin C ester derived from L-ascorbic and palm oil. 

“Like derivatives, esters are more stable than the original nutrient and therefore are thought to penetrate deeper and maintain potency and efficacy longer,” del Rosario says. “Similarly to sodium ascorbyl phosphate, ascorbyl palmitate is recommended for especially sensitive skin as it is less potent and less potentially sensitizing than L-ascorbic acid alone.”

Retinyl Ascorbate

“An ester of both retinoic acid and ascorbic acid, this specific ester is a fatty acid and is especially effective when used for protecting against environmental damage within the skin's lipid barrier,” del Rosario says. 

No matter which type of vitamin C is used in a skincare formula, they all have one common goal, and that’s to have ascorbic acid penetrate and have activity in the skin. 

“But different types are chosen based on factors like other actives in the product, the vehicle (cream, anhydrous, serum, etc.), shelf life, and packaging,” Dr. Belkin says. “One main differentiating point is whether the compound is water-soluble or lipid-soluble. The latter may help increase penetration since the stratum corneum is hydrophobic (blocks water); this would require a product that has an oil base. More stable, water-soluble forms like ascorbyl glucoside might be best for sensitive or rosacea-prone individuals since it is less potent than pure ascorbic acid.” 

However, del Rosario advises that when shopping for a vitamin C skincare product, you should consider the type of overall formula instead of the form of vitamin C, since that is more important for your skin type. 

“For example, combination to oily skin types might like a vitamin C serum for its lighter weight consistency, whereas some skin types might enjoy vitamin C in a moisturizer,” del Rosario says. “If you're concerned about pigmentation around the high points of the cheekbones or fine lines around the temples, you might go with an eye cream with vitamin C. Select the right formulation or format of vitamin C to achieve your skin goals.”

Luckily, Youth To The People offers plenty of products with vitamin C to choose from. The entire Superfood family includes the ingredient, including the Superfood Cleanser, Superfood Air-Whip Moisture Cream, and Superfood Hydrate + Firm Peptide Eye Cream, as well as the entire Superberry family, including the Superberry Hydrate + Glow Dream Oil, Superberry Hydrate + Glow Dream Mask, and Superberry Dream Eye Cream. Finally, with the highest dose, there’s the 15% Vitamin C + Clean Caffeine Energy Serum.

Written for Youth To The People by Celia Shatzman