Table of Contents
1. Introduction
In my post on Ascorbyl Tetraisopalmitate, I discussed what we’ve learned from research on this Vitamin C derivative. In this post, you’ll find everything you (don’t) need to know about the benefits of another form of Vitamin C: Ethyl Ascorbic Acid.
I use the EAA abbreviation sometimes in the post. It’s kind of a long name.
By the way, there’s no distinction between “form of Vitamin C” and “Vitamin C derivative”. I use both of them just to maintain some variety. “Vitamin C derivative” is probably more appropriate from a scientific perspective, but I’m not a scientist. I’m a scientist trapped in a middle-aged male blogger’s body!
2. What is Ethyl Ascorbic Acid?
Ethyl Ascorbic Acid is a Vitamin C derivative that’s said to offer similar benefits to Ascorbic Acid: antioxidative protection, photoprotection, stimulation of Collagen and reduction of hyperpigmentation. It is very stable thanks to its chemical structure.
An interesting claim is that it doesn’t need to be converted to Ascorbic Acid -the only naturally occurring form of Vitamin C- to have an effect.
It goes by various names, such as 3-O-Ethyl Ascorbic Acid and 3-O-Ethyl Ascorbate.
Chemical structure of EAA
Ethyl Ascorbic Acid resembles Ascorbic Acid probably more than any other form of Vitamin C. As a matter of fact, their structures look almost identical. The difference is that EAA has an Ethyl group at the third carbon position.
So what does this mean for those of us who don’t have a degree in Chemistry? Two things, mainly.
A) EAA is way less prone to oxidation than Ascorbic Acid.
B) EAA has both hydrophilic and lipophilic properties. So, in theory, it may penetrate skin better than Ascorbic Acid.
3. Ethyl Ascorbic Acid benefits for skin
There’s limited research on Ethyl Ascorbic Acid for the time being, and most of it is in vitro (not on living organisms). However, if it does act in a similar manner to Ascorbic Acid, then it may offer similar benefits.
The existing research is promising. It seems that Ethyl Ascorbic Acid does have benefits for the skin.
3.1. Antioxidative properties of Ethyl Ascorbic Acid
EAA is a great antioxidant but it may be less potent than Ascorbic Acid. In a couple of studies, the free radical scavenging ability of Ascorbic Acid was higher.
The chemical structure of EAA makes it less potent than Ascorbic Acid. On the other hand, it also makes it more resistant to oxidation.
Ascorbic Acid oxidizes faster, especially in water-based products. Even stabilized Ascorbic Acid serums gradually lose some of their potency. EAA retains its potency for longer.
3.2. Ethyl Ascorbic Acid for hyperpigmentation
Just like Ascorbic Acid, Ethyl Ascorbic Acid inhibits Tyrosinase activity, an enzyme that’s a key player in melanogenesis. (melanin production).
Ethyl Ascorbic Acid can both prevent and reduce hyperpigmentation. This was shown in lab experiments on human skin models.
So what about actual humans, models or not? In a small clinical trial on Asian women, just a 2% concentration had a brightening effect after 28 days.
EAA is likely to have a synergistic effect with other Tyrosinase inhibitors, such as Ferulic Acid.
3.3. Anti-aging benefits of Ethyl Ascorbic Acid
Just like many antioxidants , Ethyl Ascorbic Acid has photoprotective benefits. It has been shown to reduce skin damage from both UVB and UVA rays. So, it is a good option for preventing UV-induced skin aging.
There’s also some evidence that it stimulates collagen production in a similar way to Ascorbic Acid. However, the evidence is based on tests on human fibroblasts, not actual humans! More research is needed, but I feel that continuous use of a good Ethyl Ascorbic Acid product can make a positive difference.
Well, maybe not for everyone, but that’s the case with most skincare ingredients!
4. Ethyl Ascorbic acid vs Ascorbic acid
4.1 Ascorbic Acid pros
- Its benefits are backed by more research than any other form of Vitamin C
- It is the only Vitamin C that occurs naturally in our skin. It needs no conversion.
- Water-based Ascorbic Acid serums with a low pH can penetrate skin, and they typically contain penetration enhancers for improved absorption
- It is relatively stable in products with a low pH (usually around 3)
- Also available in anhydrous formulations that may be more stable and less irritating
- It may offer stronger antioxidative protection if it is not oxidized
4.2 Ethyl Ascorbic Acid pros
- It may not need conversion to Ascorbic Acid, according to some cosmetic brands
- Way less prone to oxidation, even in water-based products
- It may penetrate skin more better than Ascorbic Acid because of its lipophilic properties
- Water-based products with EAA may be less irritating because they don’t to be formulated at a very acidic pH
- Less irritation means that EAA may be easier to combine with strong actives such as Retinol and Glycolic Acid
5. Ethyl Ascorbic Acid skin penetration
Thanks to its lipophilic properties, Ethyl Ascorbic Acid is said to have better permeability than Ascorbic Acid and other water-loving Vitamin C derivatives. In simple English, it may reach deeper skin layers.
That’s not a reason to ditch your favourite Ascorbic Acid serum, though. Most skincare products with Ascorbic Acid contain penetration enhancers, anyway. These are ingredients that help actives penetrate more deeply.
EAA and penetration enhancers
Actually, Ethyl Ascorbic Acid may also need a helping hand for improved penetration. An interesting study examined its penetration with a variety of penetration enhancers. Propylene Glycol, Pentylene Glycol and Isopropyl Alcohol gave good results. Oh, and good old-fashioned Glycerin improved its penetration too.
The study was performed on porcine skin. That’s a fancy way to say “pig skin”. The latter is approved for use in research because it bears resemblances to human skin.
Come on, stop frowning: some well-known research on Ascorbic Acid was also conducted on porcine skin.
6. Ethyl Ascorbic Acid conversion to Ascorbic Acid
Vitamin C derivatives typically need to be converted to Ascorbic Acid to be biologically active. One would expect the same for Ethyl Ascorbic Acid.
I couldn’t find a clear-cut answer to that. There’s conflicting evidence online. It’s time for me to do the one thing that I excel at: confuse you even more.
Some companies state that Ethyl Ascorbic Acid doesn’t have to be converted to Ascorbic Acid. Deciem’s website, for example, says that it is a “direct-acting” form of Vitamin C. La Clinica company also states that no conversion is required.
On the other hand, a review on Vitamin C derivatives says that there’s simply no data on this conversion. I couldn’t find any myself.
A cosmetic ingredients supplier states in a datasheet that EAA is metabolized as pure vitamin C in the living body”. This statement is confusing to me. Do they mean that EAA is converted to Ascorbic Acid? Or that our body utilizes EAA just like it would utilize Ascorbic acid, with no need for conversion?
Another cosmetic ingredient supplier states that “EAA is metabolized to pure Ascorbic Acid’.
Ethyl Ascorbic Acid and Ascorbic Acid look similar
So, to convert to Ascorbic Acid or not to convert? This is a trillion-dollar question that’s been tormenting the human race for centuries.
My guess is that Ethyl Ascorbic Acid may not need to be converted to Ascorbic Acid because their chemical structures are very similar. Or it may be very easily converted.
That’s very promising. Promising enough for me to start looking for EAA serums as I am writing this post! Still, the eternal sceptic inside of me is longing for more solid evidence. About everything, not just EAA.
7. Ethyl Ascorbic Acid stability
One of the biggest assets of Ethyl Ascorbic Acid is its stability in water-based formulations. Thanks to its chemical structure, it is way more resistant to oxidation than Ascorbic Acid. This has been confirmed by various studies.
Ethyl Ascorbic Acid and pH
There’s conflicting data regarding the optimal pH for water-based Ethyl Ascorbic Acid products. According to one study, the optimal pH is 5.46. According to another study, it shouldn’t be above 5. An ingredient supplier states that the optimal pH is 6.5.
Confused? So am I! But there’s no doubt that Ethyl Ascorbic serums are more stable at a higher pH than Ascorbic Acid serums. This makes EAA a better option for people with sensitive skin that can’t tolerate products with a very acidic pH.
Ethyl Ascorbic Acid is also more stable at higher temperatures. Still, if you live in an area with a very hot climate, I recommend you store your EAA serum in the fridge.
Quite a few serums with Ethyl Ascorbic Acid are anhydrous. This makes them even more stable. Anhydrous serums with plain Ascorbic Acid also tend to be more stable.
8. Ethyl Ascorbic Acid combinations with other ingredients
Ethyl Ascorbic Acid should be fine to combine with the vast majority of skincare ingredients, with the exception of Copper Peptides. Well, maybe.
8.1. Ethyl Ascorbic Acid and Copper Peptides
It is often said that Copper Peptides may oxidize Ascorbic Acid if applied at the same time. My understanding is that Copper and Ascorbic Acid shouldn’t be formulated in the same product. But I haven’t found any clear-cut evidence that Copper Peptides oxidize Ascorbic Acid when applied simultaneously on the skin. It is not unlikely though, and I personally don’t apply them in the same routine.
And there is definitely no data regarding the combination of Ethyl Ascorbic Acid and Copper Peptides. I actually wonder if EAA is less prone to oxidation from Copper Peptides because of its structure.
But for the time being, I guess it’s a good idea to avoid using them at the same time. Or if you want to use both at night, perhaps you can apply Copper Peptides in the evening and EAA before going to bed.
Deciem advises against combining both Peptides and Copper Peptides with Ethyl Ascorbic Acid.
8.2. Ethyl Ascorbic Acid and Niacinamide
The myth that you shouldn’t use Vitamin C and Niacinamide together was debunked a long time ago. As a matter of fact Ethyl Ascorbic Acid and Niacinamide have a different mode of action against hyperpigmentation. This means that they may be a great combo for skin brightening and reduction of dark spots.
9. Ethyl Ascorbic Acid recommended concentrations
There’s not enough data on the ideal concentration of EAA in cosmetics. A concentration as low as 2% was found effective for skin brightening.
Nowadays, there are EEA with very high concentrations, even 30%! If you haven’t tried EAA or Ascorbic Acid before, I recommend you start with a product with 15%, such as the one from The Ordinary, just to check how your skin reacts to it.
As I mentioned above, Ethyl Ascorbic Acid may have less antioxidative capacity than Ascorbic Acid. However, I personally think that a 15% concentration is more than enough for protection against oxidative stress.
10. Ethyl Ascorbic Acid side-effects
A few isolated cases of allergic reactions to Ethyl Ascorbic Acid have been reported. That’s not a cause for concern for most people, in my opinion. The vast majority of skincare ingredients will cause allergic reactions to some people. If you haven’t used EEA before, it may be a good idea to patch-test it on a small area of your face.
And bear in mind that irritation and allergic reaction are not the same thing! If you get some minor redness that subsides with frequent application of an EEA serum, then you are not allergic to it.
11. Ethyl Ascorbic Acid recommended products
Below you’ll find three products with high concentrations of Ethyl Ascorbic Acid that I highly recommend. For more products, click here to see a list of products on the amazing Incidecoder website.
11.1 The Ordinary Ethylated Ascorbic Acid 15%
This is an ideal option for novice Vitamin C users. A 15% concentration of Ethyl Ascorbic Acid should be high enough to see some benefits on your skin. In a trial that I mentioned above, the volunteers experienced skin brightening with just 2%.
This serum is anhydrous, which means that it will keep its potency for a long time.
The only other ingredient is Propanediol, a Glycol that improves the penetration of Ethyl Ascorbic Acid. Propanediol leaves a finish that feels a bit greasy but it’s not really an oil and it’s unlikely to clog pores.
Buy from Skinstore (best for US customers)
11.2 Face The Theory Regena C30
I am not an affiliate with this company and I won’t earn any commission if you buy from my link. But I had to include a link to their EAA serum because it’s a great option for all skin types.
Face The Theory is a brand that I discovered recently and they have various intriguing and affordable products. This is one of them: it contains 30% Ethyl Ascorbic Acid. That’s a very high concentration and it should last a long time because you only need a few drops.
11.3 Allies of Skin 20% Vitamin C Brighten + Firm Serum
Allies of skin is an up-and-coming brand with very interesting formulations.
This product contains 20% Ethyl Ascorbic Acid, plus a mix of potent antioxidants with potential benefits for the skin. A very interesting one is Ergothioneine, a naturally occurring antioxidant with photoprotective properties.
Other antioxidants include Dimethylmethoxy Chromanol, Glutathione, and Vitamin E.
Another intriguing ingredient is the Citrus Aurantium Dulcis Callus Culture Extract. This is basically an extract of Bitter Orange Stem Cells. Some research on Orange stem cells has shown that they improve elasticity and trigger Collagen synthesis. The research is linked to a cosmetic ingredient supplier, but it’s promising.
This serum is pricey, but I’m happy to recommend more expensive products if their formulas are worth it. Even if I can’t afford them myself! However, sometimes there are crazy discount codes. At the moment of writing this post, BeautyBay has a 50% discount on all Allies Of Skin products and they are all out of stock, of course!
This product contains possibly the longest ingredient name EVER: Benzimidazole Diamond Amidoethyl Urea Carbamoyl Propyl Polymethylsilsesquioxane. My current life goal is to memorize it.
12. References
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Numata T, Kobayashi Y, Ito T, Harada K, Tsuboi R, Okubo Y. Two cases of allergic contact dermatitis due to skin-whitening cosmetics. Allergol Int. 2015;64(2):194-195.
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What’s your experience with Ethyl Ascorbic Acid; Leave a comment below!
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