Is Tetrahexyldecyl Ascorbate the Best Vitamin C For Your Skin?
by Heather Smith on Nov 01, 2022
There's no debating the skin benefits of Vitamin C! When it comes to the best option for your skin, we are on team tetrahexyldecyl ascorbate.
The issue is that although L-ascorbic acid is often touted as the "best" version to use, it is a notoriously unstable molecule. It's also quite irritating because of the high concentrations needed to be effective.
There are so many types of Vitamin C in skincare; figuring out what will work for you can take time and effort.
This article will help you learn what type of Vitamin C tetrahexyldecyl ascorbate is and why you should consider using it over other types.
What Is Tetrahexyldecyl Ascorbate
Tetrahexyldecyl ascorbate is also known as THD-ascorbate. It is an oil-soluble form of Vitamin C. From a chemistry standpoint, THD-ascorbate is a Vitamin C ester. That means it is a chemically modified form of Vitamin C.
In the case of Vitamin C, the esterification process changes the solubility from water to oil and improves the shelf-stability of the molecule. The most important thing to know is that the esterification reaction is reversible, which is why THD-ascorbate is so cool and such an amazing skincare ingredient.
How Tetrahexyldecyl Ascorbate Works
The reason we love face oil so much is that oil-soluble active ingredients are often able to penetrate better because they're waterless. That's why we are so excited to introduce you to this ingredient, which is featured in our Vitamin C oil. Penetration vs absorption is an important concept to understand when it comes to skincare effectiveness.
Tetrahexyldecyl ascorbate is a lipid-soluble precursor to L-ascorbic acid. Since it is oil soluble, it is rapidly and easily able to penetrate the waterproof outer layer of your skin, the stratum corneum.
When THD-ascorbate is applied topically, it is taken up and converted back into L-ascorbic acid. While it's hard to know the exact cellular process (and we don't endorse animal testing), the proof comes from in vitro tests (human cells in a lab) and in-use studies of people using products containing it.
Benefits Of Tetrahexyldecyl Ascorbate
The main benefit of tetrahexyldecyl ascorbate is that it penetrates the skin better and faster than traditional L-ascorbic acid. Once converted within the skin, it exerts the same effects. It is also stable and won't degrade effectiveness while sitting on the shelf - no yellow/brown staining either!
Since it isn't a direct acid, it is much more suitable for sensitive skin and less likely to irritate or damage your skin barrier.
All Vitamin C products will exert varying anti-aging effects, including improving collagen synthesis and quality. You would expect to see the same benefits as using traditional ascorbic acid:
- Improved tone, brightness, and lightening of dark spots
- Improved elasticity and firmness from collagen effects
- Antioxidant effects at the cellular level once converted from THD-ascorbate
- Improved fine lines and wrinkles and overall skin health
Like traditional L-ascorbic acid, the effects are concentration-dependent. Tetrahexyldecyl ascorbate has been shown to reduce hyperpigmentation, even in melasma, at high concentrations. It also boosts the effectiveness of other active ingredients that target age-related skin changes.
What Are the Risks of Using Tetrahexyldecyl Ascorbate
Tetrahexyldecyl ascorbate is not known to have significant side effects, even when used with retinol. Although any Vitamin C ingredient may irritate sensitive skin, it is considered mild and non-irritant. THD-ascorbate is an excellent addition to your beauty routine.
There is some scientific debate about whether THD-ascorbate functions as an antioxidant. It does have powerful antioxidant properties, but that is only after it is converted back to ascorbic acid in the skin. It is a stable molecule with a long shelf-life and doesn't degrade while sitting around. One manufacturer has published data that it's best to use THD-ascorbate with another antioxidant, but the one they recommend is also produced by them so there could be commercial bias to that data. Other manufacturers haven't found the same results.
How To Apply Vitamin C Serum
Although you've probably added Vitamin C to your diet, you can't just put it on your skin. That's where Vitamin C serums come in. Even traditional L-ascorbic acid needs to be dissolved and stabilized into a serum form for incorporation into your skincare routine. It is always good practice to do a proper patch test before use.
Wash your face (and dry it well) before applying. Depending on your skin type, you may need to layer this type of serum with others (or find a multi-use product), i.e. hyaluronic acid.
It's well-known that regular L-ascorbic acid doesn't play nicely with other ingredients. Usually avoiding niacinamide and retinol (and sometimes other ingredients) is recommended. The same issue isn't known to be an issue with THD-ascorbate.
Tetrahexyldecyl ascorbate is safe to use with retinol!
Before or After Moisturizer?
One of the best things about oil serums is that they can also act as a moisturizer. Some people don't need a separate product because the other oils in the serum are moisturizing emollients.
That's not true for all people.
In general we always recommend using your face oil as the last step in your skincare routine so that you can lock in all the moisture and goodness below.
One exception to this general rule is when you're using a highly active oil serum with powerful ingredients like tetrahexyldecyl ascorbate. In this situation, we recommend putting your serum on first and waiting about 5 minutes before you moisturizer.
How Often to Use Vitamin C Serum
Once or twice a day is best.
It will take time for you to experience results; give yourself at least four weeks to see visible skin tone and texture changes. If you use your serum in the morning, be sure to layer it underneath your sunscreen.
Tetrahexyldecyl Ascorbate vs Ascorbic Acid
This debate may never be fully answered because the preference of one over the other is often a personal choice. Also, there have yet to be any high-quality studies comparing the two ingredients head-to-head. With so much variability in available products, concentrations, and activity levels, a clear winner is hard to declare.
This infographic compares the pros and cons of both ascorbic acid vs tetrahexyldecyl ascorbate to help you decide what's right for you.
Ascorbyl Tetraisopalmitate vs Tetrahexyldecyl Ascorbate
A different form of oil-soluble Vitamin C is called ascorbyl tetraisopalmitate. There is a misperception that it is the same as THD-ascorbate – they are not synonymous.
Since chemical modification and esterification can be done differently (i.e. different lab processes), some molecular differences may exist. For those of us who have no idea the difference between things like isopalmitic acid, hexadecanoic acid, and 2-hexyldecanoic acid, the big question is - is there an important difference in the results or the stability of using the molecule?
More research is needed to decide if there is any clinical relevance to the differences; currently, it is felt the answer to that is probably not.
A third version of oil-soluble Vitamin C is called ascorbyl palmitate. This version is less effective as a topical skincare ingredient. Still, it is a powerful antioxidant that helps stabilize other molecules in a formula - so it has a role to play too.
Vitamin C Serum Safety in Pregnancy
Pregnancy safety and skincare is a pet peeve topic for us because brands play on women's fears during the most vulnerable time in their life.
The first thing to do is always discuss your concerns with your doctor for reassurance and education.
However, when it comes to using topical substances on your skin, absorption into your bloodstream just frankly is not an issue. Certain highly potent medications are an exception (think tretinoin and hydroquinone), but these shouldn't be used without medical supervision.
There is no reason why topical Vitamin C would have safety concerns.
There you have it! Our favorite form of Vitamin C.
Tetrahexyldecyl ascorbate is more stable and is less irritating than ascorbic acid.
THD-ascorbate is an efficient delivery system of Vitamin C. Its lipid solubility and prodrug quality penetrate the skin more efficiently than L-ascorbic acid (LAA), so enzymes can quickly metabolize it into the active form.
If you're shopping for an effective tetrahexyldecyl ascorbate serum, check out bareLUXE Skincare's Radiant Glow Elevated Brightening Oil. This Vitamin C Oil Serum combines powerful brightening botanical extracts with THD-ascorbate to target uneven pigmentation and dark spots.
Pair our Vitamin C Oil with our Natural Exfoliating Face Scrub and your glow will be radiant in no time.
Stamford NP. Stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives. J Cosmet Dermatol. 2012 Dec;11(4):310-7.
Kelm RC, Zahr AS, Kononov T, Ibrahim O. Effective lightening of facial melasma during the summer with a dual regimen: A prospective, open-label, evaluator-blinded study. J Cosmet Dermatol. 2020 Dec;19(12):3251-3257.
National Center for Biotechnology Information. PubChem Compound Summary for CID 10260680, Tetrahexyldecyl ascorbate. https://pubchem.ncbi.nlm.nih.gov/compound/Tetrahexyldecyl-ascorbate.
National Center for Biotechnology Information. PubChem Compound Summary for CID 1012449. https://pubchem.ncbi.nlm.nih.gov/compound/1012449.
Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013 Apr;4(2):143-6.