Topical Vitamin C offers a wide array of benefits to the skin. However, many forms of Vitamin C and many more formulations of Vitamin C are available commercially with a potential to confuse the audience.
The guide offers guidance on the formulations of Vitamin C offered under The Ordinary range. It also offers education on Vitamin C itself and on the differences between formulations of Vitamin C at large.
The Ordinary offers Vitamin C Suspension 23% + HA Spheres 2%. This product is a water-free, silicone-free suspension of 23% L-Ascorbic Acid powder and as such offers extremely potent direct topical exposure to Vitamin C. The Ordinary's portfolio of Vitamin C is expanding in October 2016 to include the following formulations:
* Note: Our brands NIOD and Hylamide offer ELAN and C25 respectively, which are solutions of Ethylated Ascorbic Acid (EAA). EAA offers as high a potency as direct L-Ascorbic Acid with minimal stinging and extremely high stability even in a solution format. The cost of EAA, however, is nearly 30 times the cost of pure L-Ascorbic Acid.
Vitamin C Suspension 23% + HA Spheres 2% (Water-free suspension, dropper format)
This format is a suspension of very fine L-Ascorbic Acid powder and, as such, provides the most direct exposure of extremely high concentrations of Vitamin C topically. With such format, there are 2 important things to consider: 1) A very strong tingling but non-irritating sensation is expected during the first 1-2 weeks of use until the skin's tolerance to such high exposure is elevated; 2) The powder exposure to the skin disallows the formula to feel like a serum, lotion or cream and each application requires a few seconds to feel absorbed by the skin. If desired, this formula can be diluted in a cream base per application to allow the skin to build tolerance over time. (Alternative products on the market offer suspensions of Vitamin C in water-free formulations in a silicone base to avoid the "powdery" feel of the suspension. These formulations do keep the Vitamin C stable but they are almost always offered in heavier silicone bases that interfere with efficient exposure of the entire Vitamin C content to the skin (the silicone entraps the Vitamin C). Our formula avoids the use of silicones and offers complete and direct exposure of the entire powder content to the skin, maximizing topical delivery.)
Ascorbyl Glucoside Solution 12% (Water-based serum, dropper format)
Ascorbyl Glucoside is a water-soluble derivative of Vitamin C. It is much more stable in water but it is less potent than direct L-Ascorbic Acid. Being more compatible with water allows for a very pleasant serum texture. It is considered a gold standard of Vitamin C derivatives due to its high stability and comfortable use, but it's impossible to achieve extremely high L-Ascorbic Acid potency with this solution. Aside from the general benefits of pure Vitamin C, Ascorbyl Glucoside has been shown to offer specific skin brightening benefits.
Magnesium Ascorbyl Phosphate Solution 10% (Water-based cream, tube format)
Magnesium Ascorbyl Phosphate (MAP) is a water-soluble derivative of Vitamin C. It is more stable in water but it is less potent than direct L-Ascorbic Acid. It is compatible with water but higher concentrations cannot be offered in a low-viscosity serum format and often require emulsification to form a lotion or a cream. This formula is a light cream that offers 10% pure MAP (very high solubilized concentration). Aside from the general benefits of pure Vitamin C, MAP has been shown to offer specific skin brightening benefits, more so than other derivatives of Vitamin C. (Note: some brands offer "powder" formulations that offer up to 15% MAP. Such powders would offer less direct availability of MAP as compared to an emulsion such as this formula which has solubilized the complete 10% concentration of MAP. It is extremely difficult to solubilize higher concentrations of MAP in non-powder formulations.)
Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F (Water-free, silicone-free serum, dropper format)
Ascorbyl Tetraisopalmitate is an oil-soluble derivative of Vitamin C that can be used in higher concentrations without drawbacks. It is one of the most stable derivatives of Vitamin C but, being a derivative, its potency will not be directly comparable to pure L-Ascorbic Acid. It is provided in this oil-format formula in combination with Vitamin F, also known as essential fatty acids. Aside from the general benefits of pure Vitamin C, Ascorbyl Tetraisopalmiate has been shown to offer specific skin brightening benefits.
General Vitamin C Guidance
The best property of any powerful antioxidant is also its worst property—it oxidizes. Basically, antioxidants bind to free “radicals” of oxygen so that your cell's don’t. The problem is that they may bind to oxygen in the bottle before you even buy any product claiming to contain antioxidants. And since Vitamin C has a very strong ability to bind to free radicals of oxygen, as soon as it’s dissolved in water, it starts to oxidize and change the colour of the solution (from clear to slight orange and later to dark orange). When this change happens, two things occur: 1) the activity of Vitamin C becomes disabled and 2) far worse, the “antioxidant” formulation actually turns into a “pro-oxidant” formulation. Many clinical skincare brands have filed patents that claims to stabilize Vitamin C in water and many have fought amongst themselves on whether or not they have breached each other’s patents. These patents and fights are simply meaningless because these respective formulations continue to show oxidation and change colour, while consumers believe that since there is a patent, this colour change might be OK. A patent grant does not verify that the function described actually works—a patent is not a validation of a discovery; it is simply an exclusivity to a position claim. Very simply, if a Vitamin C formula turns colour, the Vitamin C is oxidized and the formula becomes potentially damaging to the skin.
Other products have gotten around the stability issue of Vitamin C by using stabilized forms of the substance. These forms take on names such as Ascorbyl Glucoside (usually used at 2%), Magnesium Ascorbyl Phosphate (MAP, usually used at under 10%), Sodium Ascorbyl Phosphate (similar to MAP) and Ascorbyl Palmitate (very controversial and usually used at less than 0.2%). There are two issues to consider with this approach: 1) These forms still need to be converted to L-Ascorbic Acid—the pure form of Vitamin C useful to the skin and so a direct potency comparison to pure L-Ascorbic Acid should not be made—and 2) the maximum amounts of these materials that can be solubilized in a formula is between 0.5% and 10% depending on the material. The Ordinary offers the most studied forms of Vitamin C derivatives (Ascorbyl Glucoside, Magnesium Ascorbyl Phosphate and Ascorbyl Tetraisopalmitate) in independent formulations. It's notable that, leaving aside the general benefits of topical Vitamin C (where pure L-Ascorbic Acid wins), the derivatives of Vitamin C have been shown to offer better brightening results than pure L-Ascorbic Acid.
A few brands offer suspensions of Vitamin C in water-free formulations. These formulations do keep the Vitamin C stable but they are almost always offered in heavier silicone bases that interfere with efficient exposure of the entire Vitamin C content to the skin. The Ordinary offers a silicone-free suspension of pure L-Ascorbic Acid. While silicone formulations feel better on the skin, they entrap the suspended Vitamin C powder, disallowing complete topical exposure.