We have talked about the science behind vitamin C skincare, we have even tested a bunch of CE Ferulic dupes - yet there’s still more for us to cover in the vitamin C serum landscape. Vitamin C is actually a whole family of related molecules that all behave slightly differently. The OG vitamin C with the glitzy skin benefits that you often hear of is L-ascorbic acid. But since ascorbic acid is notoriously unstable in the presence of light, water, and air, many have turned to derivative compounds of vitamin C as an alternative. These vitamin C derivatives are essentially chemically modified versions of ascorbic acid to improve vitamin C stability. There are a LOT of vitamin C derivatives to choose from on the market such as ascorbyl glucoside, THD ascorbate, ethylated vitamin C, etc. We can already tell you that these are not all created equal. So let’s take a closer look at this complex product landscape and learn how to spot a vitamin C derivative, when to consider trialing a vitamin C derivative, and what is the best vitamin C derivative.
How do I know it’s a vitamin C derivative?
Before we dive into the science behind vitamin C derivatives, we first have to address the question “How do I know if a product uses a vitamin C derivative?” Decoding ingredient lists isn’t always that helpful in guiding your purchase decision. However, when it comes to vitamin C products, we find it’s an absolute necessity. The reality is, regardless of what kind form of vitamin C a serum uses, more often than not, the product description will simply say “vitamin C” on the label. Definitely give the ingredient list a scan to see just which vitamin C they’re talking about. You’ll most likely spot one of the 3 following types of ingredient names:
Ascorbic Acid: This is the OG vitamin C. Check out our dedicated blog posts for more info! It’s important to note that 3-o ethyl ascorbic acid is a derivative and NOT the same molecule as L-ascorbic acid.Ascorbyl XYZ: This is a big group of vitamin C derivatives. You’ll find ingredients such as “ascorbyl glucoside” “sodium ascorbyl phosphate” or “ascorbyl palmitate”. Though they have similar-sounding names, their skin benefits, stability profile, and use levels can all differ!
XYZ Ascorbate: There are a few ingredients in this category that has gained popularity in the past few years such as THD (tetrahexyldecyl) ascorbate and glyceryl ascorbate
Still confused? We've created a general layout of the product landscape with a few examples of popular vitamin C serums that include gold standard ascorbic acid as well as ones that use derivatives. Take a look!
When should you consider switching to a vitamin C derivative?
In general, we would still give ascorbic acid products a try before considering a different form of vitamin C. The reality is, good ol’ ascorbic acid is still the most tested, validated form of vitamin C. So it’s still the most surefire way to get the brightening, antioxidant, anti-aging skin benefits you’re looking for. That said, with skin being as quirky and personal as it is, it’s possible it might not work for everyone. You might find that your ascorbic acid serum is hard to keep fresh and keeps turning brown on you. You might find the hotdog water scent too off-putting. And most importantly, your skin might be easily sensitized by ascorbic acid.
Ascorbic acid serums typically sit at a fairly low pH (under 3.5) with high active concentrations (on average 15-20%), which can all be tough product traits for those with sensitive skin. The anhydrous forms of ascorbic acid serums can also be problematic. These can come with >80% solvent loads like the Ordinary’s 8% ascorbic acid 2% arbutin serum when typical skincare serums may only have ~10% solvents. These high solvent loads can also be a trigger for some skin types. So if you have sensitive skin and struggle with skin reactions, you might want to consider a vitamin C derivative instead.
That said, there isn’t an automatically “best” vitamin C alternative for sensitive skin. Each formula is still unique, depends on various factors, and definitely requires patch testing.
Show me the data! Do vitamin C derivatives work?
If you’re on the market for an ascorbic acid alternative, the first question you need to ask is “What is the skin benefit you’re hoping to get from vitamin C? Vitamin C’s 3 main skin benefits are: antioxidant protection, brightening & tackling hyperpigmentation, and boosting collagen production. These are all originally tested from the ascorbic acid version, and these skin benefits do not automatically apply to the derivatives.
There are a LOT of vitamin C derivatives to choose from, which means this can get pretty overwhelming really fast. We’ll run through the main vitamin C derivatives you’ll run into, what they’re good for, and the representative products that use these derivatives.
Sodium Ascorbyl Phosphate
- Tested benefits? Antioxidant (not as potent as ascorbic acid), brightening, and one of the few vitamin C molecules tested for acne.
- Chemists’ notes: Best vitamin C for those with sensitive, oily skin. This guy doesn’t appear to absorb as well as ascorbic acid. Consistent application to clean skin is the key!
- Representative products with SAP: Mad Hippie Vitamin C Serum, Sephora Super Glow Serum, TruSkin Vitamin C Facial Serum, and a lot of Amazon serums
- Tested benefits? There’s a tiny study on THD ascorbate’s ability to brighten hyperpigmentation. Antioxidant benefits have only been tested in vitro. The good news is that since this is one of the few oil-based vitamin C, it does appear to absorb into skin well.
- Chemists’ Notes: This is incredibly popular with very little data outside of a few trade publications. Would only recommend based on individual product merits (i.e. if it comes with a killer clinical test).
- Representative products with THD Ascorbate: Sunday Riley C.E.O. 15% Vitamin C Brightening Serum, Peter Thomas Roth Potent-C Power Serum, Herbivore Nova 15% Vitamin C + Turmeric Brightening Serum, Strivectin Super-C SPF 30 Moisturizer
3-O Ethyl Ascorbic Acid
- Tested benefits? Very little data - most of the data lies in the skin brightening, hyperpigmentation arena. We have no insights on whether or not it functions as an antioxidant or promotes collagen production.
- Chemists’ Notes: We would put this in the bucket of - reputation seems to precede actual data. This is an incredibly popular ingredient. We’d recommend looking for products that have testing behind it.
- Representative products with 3-o ethyl ascorbic acid: Ole Henriksen Banana Bright 15% Vitamin C Dark Spot Serum, Allies of Skin 20% Vitamin C Brighten + Firm Serum, Niod 30% Ethylated Ascorbic Acid, The Ordinary 15% Ethylated Ascorbic Acid
- Tested benefits? Ascorbyl glucoside has demonstrated all 3 core benefits of vitamin C (antioxidant, slows down melanin production, and promotes collagen) - all in vitro. Topically, ascorbyl glucoside is most often used in brightening products that target hyperpigmentation and promote even skin tone.
- Chemists’ Notes: This is a popular form of vitamin C often found in Kbeauty and Jbeauty skincare products.
- Representative products with Ascorbyl Glucoside: Inkey List 15% Vitamin C and EGF Serum, The Ordinary 12% Ascorbyl Glucoside Solution,
Magnesium Ascorbyl Phosphate
- Tested benefits? It’s a proven skin brightener like many other derivatives on this list. But! What’s interesting is that this molecule has been evaluated for collagen-boosting properties. In one study, magnesium ascorbyl phosphate actually demonstrated that it can accelerate collagen production and assembly in wound healing.
- Chemists’ Notes: like SAP, magnesium ascorbyl phosphate doesn’t have the best track record getting absorbed by skin. Consider using twice a day consistently.
- Representative products with MAP: Glossier Super Glow, Timeless Hyaluronic Acid + Vitamin C Serum,
- Tested benefits? Weirdly enough, glyceryl ascorbate seems to be great hydrators… It’s unclear whether or not it functions at all like a traditional vitamin C.
- Chemists’ Notes: This is the new guy we expect to see more in the near future. There are actually a few different versions of this (e.g. bis glyceryl ascorbate, glyceryl-3 ascorbate, etc). Given that it’s so new, we’d place a lot of weight on testing done on the actual products
- Representative products with glycerol ascorbates: Tatcha Violet C Serum, St. Jane Vitamin C Glow Drops
- Tested benefits? This one isn’t the most popular but has been around for quite some time. There is a tiny study that was done measuring its brightening benefits. It has been looked at for its antioxidant properties and collagen benefits as well, but all in vitro.
- Chemists’ Notes: The actual concentration needed to reap these benefits still seems uncertain. In literature, it can vary a lot and you’ll find concentrations as low as 1%. There’s still a lot of guesswork here.
- Representative products with glycerol ascorbates: The Ordinary 20% Ascorbyl Tetraisopalmitate Solution
To help visualize all of these derivatives, here is a crude map of the Vitamin C Derivative space based on their in vivo (human or animal) testing.
Key Takeaways and FAQ
This is definitely a lot of information to digest in one go! Vitamin C derivatives are a very diverse landscape that is worthy of exploration especially if you just haven’t found an ascorbic acid product that works for your skin. Sadly, there isn’t one we could say is for sure a 1:1 replacement of good ol’ l-ascorbic acid with all its tested benefits.
Do vitamin C derivatives really work?
It can depend on your skin goal! Most vitamin C derivatives like ascorbyl glucoside, THD ascorbate, and 3-o ethyl ascorbic acid are primarily tested for skin brightening benefits. If you’re looking for antioxidant protective powers, sodium ascorbyl phosphate seems to be the best bet of the bunch followed by ascorbyl glucoside.
I have oily, breakout-prone skin, what is the best vitamin C for me?
SAP sodium ascorbyl phosphate is the one vitamin C form that has been tested specifically on acneic skin. We’d recommend starting there for those with oily, sensitive skin.
How do I store vitamin C derivatives?
They might be more stable than ascorbic acid, but that doesn’t mean they’re ultra-degradation-proof. We’d still recommend general vampire settings and keeping an eye out for any formula color changes and separation.
How do I incorporate vitamin C derivatives into my routine?
For the most part, the same thing applies! Most of these that come in water-based serum formats, we’d recommend using vitamin C serums as the first step after cleansing. There are a few like THD ascorbate that you can find in emulsions since they are oil-based. We would apply these post toner/serum/water stuff step.
When data is in short supply, we give a lot of credit to products with testing. So if you’re not sure which vitamin C derivative is right for you, we’d recommend looking for products that have been through at least 8 weeks of testing to gauge whether or not these products can deliver the skin benefits you’re looking for.
Products Referenced in the Blog
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