The Ordinary Guide
to Vitamin C.

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's portfolio of Vitamin C formulations is listed below.

Tap product name to view product details.

Product Key Benefits Strength Possibility of Tingling Texture May Suit Frequency When to Use

(Water-free suspension, tube 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. This formula feels gritty on the skin for a few seconds. If this feeling is not desirable, we would suggest Vitamin C Suspension 30% in Silicone.

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Much like our Vitamin C Suspension 23% + HA Spheres 2% formula, this product also offers a suspension but in light silicones for a smooth, non-gritty skin finish. Despite the very light forms of silicones used, silicones do impair dermal exposure to Vitamin C slightly but the additional (30%) concentration of Vitamin C helps compensate for this slight inefficiency. 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. If desired, this formula can be diluted in a cream base per application to allow the skin to build tolerance over time.

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(Fine 325 Mesh Topical Powder) The 100% L-Ascorbic Acid Powder visibly targets the appearance of uneven skin tone, dullness, and signs of aging and is formulated to be mixed with other treatments (except those containing Niacinamide or EUK 134). The format of this formula is a very fine, anhydrous, L-Ascorbic Acid powder and, as such, provides the most direct exposure of extremely high concentrations of Vitamin C topically. With such format, 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. To ensure freshness and to prevent any oxidation, it is preferable to immediately use after mixing especially when mixed with water-based products. For maximum benefit from peptides and LAA individually, please alternate use between the two and avoid mixing the LAA powder with peptide-based products. The quantity of powder can be adjusted based on tolerance. We recommend using between a quarter to half a scoop mixed in with 5-10 drops of serum or a pea-dime size of emulsion based products.

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(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.

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(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.

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(Anhydrous serum, dropper format) The Ethylated Ascorbic Acid 15% Solution is an exceptionally-stable solution Ethylated Ascorbic Acid. This water-free formula offers a direct-acting approach to achieving a radiant, healthy-looking skin tone. Unlike other Vitamin C derivatives, this ethylated form acts directly like Vitamin C, is closer in molecular weight to actual Vitamin C which allows for faster visible results, and offers a much better stability profile than any known direct-acting form of Vitamin C. Since this formulation is a water-free solution, it may feel slightly "oily" for a few seconds after application, despite the absence of all oils.

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Patch testing prior to use is advised. Refer to our in-depth guide to patch testing .


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 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 both silicone-free suspensions of pure L-Ascorbic Acid and a smooth-finish suspension in very light silicones to minimize any impairment to dermal exposure.

* Note: For customers wishing to explore higher concentrations of Vitamin C in a solution format, The Ordinary's sister brand NIOD offers Ethylated L-Ascorbic Acid 30% Network (ELAN) - a formula containing 30% Ethylated Ascorbic Acid in a water-free serum.