Deciem The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F

Time for another Deciem The Ordinary review. Every time I feel like I’m close to running out of products to review from this line they make a dozen more. I feel like I could go on forever with this brand. Next up is the Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F. The name alone has me tongue tied and twisted. Details per The Ordinary:

Vitamin C is an effective antioxidant, brightens the skin tone and reduces signs of ageing. 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.

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. We have developed a guide that 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. Please click here for this guide. 

Note: Supplied in UV-protective packaging.

Directions Apply a few drops to the entire face in the AM and/or PM.

This is essentially a non L-Ascorbic Acid, highly stable form of vitamin C serum in a light dry oil base. It’s a pale straw colored oil. I don’t recall any scent. The packaging is the typical The Ordinary dropper in glass bottle style. I still want a pump as I hate droppers, but at the cheaper prices beggars can’t be choosers. The bottle is at least dark and prevents it from breakdown in the sunlight. The texture of this oil is so lightweight. It’s got that dry oil finish and it absorbs quickly. Squalane and jojoba oil agree with my skin very well. I love those lightweight oils.

This isn’t the cheapest vitamin C The Ordinary makes at $17.80 for an ounce. It’s actually the most expensive of the vitamin C formulas they have right now. It lasted forever as you only need a few drops at a time. L-Ascorbic Acid, or L-AA for short, is the form of vitamin C I tend to prefer as my skin can handle the harsher vitamin C. L-AA is the less stable form of vitamin C as well as the most powerful. It also has the harsher side effects such as stinging and irritation to more sensitive prone skin types. All other forms of vitamin C like Tetrahexyldecyl Ascorbate are more stable and have less harsh side effects. So no stinging or irritation. They’re also less powerful so you get less brightening.

I ended up using this at night mostly for building collagen. It did brighten some as well but not as much as my day L-AA does. At the time when I was using this I was using Drunk Elephant C-Firma in the day and this at night. I wasn’t wearing oils in the daytime at all while testing this. I stayed away from oils for a while, especially in the day. I actually have started wearing oils again even in the daytime. This is such a light texture and it could be AM, PM or both even. So unless you avoid oils at all costs this should suit most skin types as squalane and jojoba aren’t usually acne prone or pore clogging oils. They’re the lighter oils. I think if you like The Ordinary and their price range, love facial oils and a gentler vitamin C this will be a win win for you.


Coconut Alkanes, Tetrahexyldecyl Ascorbate, Ethyl Linoleate, Coco-Caprylate/Caprate, Simmondsia Chinensis (Jojoba) Seed Oil, Solanum Lycopersicum (Tomato) Fruit Extract, Squalane.


I always find Deciem’s extra info very fascinating. Here’s some extra about vitamin C per their site:

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.

Some brands and publications claim that Vitamin C has dermal benefits in an oxidized state in response to questioning of unstable formulations. We have prepared A Discussion of L-Ascorbic Acid and Dehydroascorbic Acid in Skincare to address this topic specifically which can be viewed here.

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 GlucosideMagnesium 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 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.


  1. Great review! Do you know anything about the Biossance vitamin c rose squalene oil? I’m wondering if this is similar. I really liked the sample I tried of the Biossance product, but can’t decide if it’s better than the DE for daily (morning) use. Would love your thoughts!

    1. I’ve never tried it sorry. Usually these oils could go either way. In the morning for brightening and antioxidants, if you like light oils in the morning. Or at night for collagen building as a night oil. It’s really more personal preference I think.

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