Vitamin C in Skincare
Vitamin C is known for its beneficial effects on skin, but did you know that it comes is more than one form? Ascorbic acid and ascorbyl palmitate are the most common forms used in skincare. Citric acid is not vitamin C, but is often mistaken as vitamin C. Let’s explore the different forms and how to use them in skincare formulations.
Ascorbic acid– AKA topical vitamin C–is the most common form of vitamin C and is available in many skin care products. Scientific studies show that vitamin C will help skin look younger by decreasing the visible signs of aging. Products that contain ascorbic acid are best used in after sun products and at night. Vitamin C is one of the many active ingredients to topical agents and can play a vital role in a regular skin care regimen. While ascorbic acid contains many benefits, it can cause products to turn a brownish color over time.
How to Use: Add to the water phase of formula. Should be formulated at pH 4-5 for best results. Recommended Usage Rate: Final concentration 0.2% – 4%
Ascorbyl palmitate is another form of vitamin C and is the salt of ascorbic acid. It’s most widely used as an extremely powerful antioxidant. Some experts believe antioxidants are the most vital weapons in the fight against aging. Ascorbyl palmitate is an active form of vitamin C that is fat-soluble and more stable than L-ascorbic acid when incorporated into products.
How to use: Add to hot oil phase of formulas; if it does not dissolve completely add vitamin C and oil to a mortar and blend the mixture thoroughly with the pestle. For external use only. Recommended Usage Rate: Final concentration 0.5%-8%.
Naturally occurring citric acid is often mistaken for vitamin C and is a member of the alpha hydroxy acid (AHA) group. Citric acid is often used as an ingredient in exfoliants and chemical peels, such as Essential’s Alpha Hydroxy Liquid Bundle, but most often citric acid is used to adjust the pH in personal care products such as lotions, cremes, shampoos, etc.
How to Use: To reduce the pH (increase the acidity) of water based products, add citric acid at approximately 0.2% during the water phase or final phase. Ideally, skin care products should have a pH between 4.5 and 5.5. In an exfoliant or chemical peel, citric acid can be added at up to 5%. Alpha hydroxy acids can irritate the skin, so exercise caution. When used at very low levels as an acidifier/processing aid, citric acid does not need to be listed on ingredient decks. Recommended Usage Rate: use at >10% or at pH <3.5.