Vitamin C in Skin Care – Varieties and How to Use Them
Vitamin C is a popular ingredient used in skincare and it seems to be even more popular than ever. You may picture an orange in your mind when you think about vitamin C, but there’s a lot more to this powerful ingredient than meets the eye.
- Vitamins sold as supplements or added to fortify foods are lab produced, it’s pretty much impossible to consume natural vitamins in any way other than by eating the foods that contain them. This is also true of Vitamins used in hair and skincare products, however, they are considered to be bio-identical to the naturally occurring vitamins found in food. This means there is no difference in how these vitamins perform.
- Vitamin C products are best used at night after sun exposure is limited. Some studies suggest using vitamin C during the day can actually increase the appearance of fine lines and wrinkles. Also, your skin does most of its work rejuvenating itself while you sleep so using Vitamin C at night can be more beneficial than using it during the day.
Vitamin C in Skin Care – More than one?
Vitamin C comes in many forms and each one has its own unique properties. Most formulators will choose the Vitamin C based on the desired effect. Some are better for exfoliation, some are water soluble, some oil soluble. Choosing the right form really comes down to knowing how each form of vitamin C behaves and the desired effect.
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 the hot oil phase of formulas; if it does not dissolve completely you can add your vitamin C and hot oil (140F) to a mortar and blend the mixture thoroughly with the pestle. You can also try using your stick blender, however, you will have better results with a mortar and pestle. 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.
Magnesium Ascorbyl Phosphate is a stable, water-soluble derivative of Vitamin C (L-Ascorbic acid). Unlike L-Ascorbic Acid, this vitamin C is much more stable and less prone to browning, especially if the pH of the final formulation is closer to a neutral 7.
How to Use: Add to the water phase of your formulation; if it does not dissolve completely, heat water to 140F – 180F and mix with high shear mixer/ stick blender. Use at 0.2% – 3%
Tetrahexyldecyl Ascorbate (THD)
Tetrahexyldecyl Ascorbate is an oil-soluble ester of Vitamin C. It has anti-oxidant superpowers and is fast becoming the most popular form of vitamin C in high-end cosmetic formulations. It has proven stability over time and very promising test results on the benefits for skin. It’s often used in products claiming to lighten skin. Typical usage rate is 0.5% – 3% but it can be used as high as 10%. This is added to the oil phase of formulations at temperatures less than 180F.
We recommend packaging products with vitamin c in opaque bottles. Exposure to light can cause the products to darken. There’s likely nothing wrong with your products if they do turn slightly brown, but they don’t look that great. By using an opaque bottle or tube, you can minimize the exposure and reduce the likelihood of a color change.
For a quick and easy way to incorporate Vitamin C into a toner, check out this recipe.