Tetrahexyldecyl Ascorbate: The New Stable Vitamin C Ingredient – Everything You Want To Know About This New Oil-based Vitamin C



What Is Tetrahexyldecyl ascorbate?

Tetrahexyldecyl ascorbate may just be the vitamin C ingredient needed to make vitamin C products that much more easy to use and versatile. Tetrahexyldecyl ascorbate is a stable oil-based form of vitamin C. It is considered to be an analog molecule to L-ascorbic acid which is the form of vitamin C used by the body. 

If you’re researching tetrahexyldecyl ascorbate, you might be looking for clean yet effective skincare. One brand we recommend is Carrot & Stick. You can read more about this brand at the bottom of the article.

The main issue with current vitamin C products is that out of the vitamin C analog ingredients, only the pure form, L-ascorbic acid has been found to improve the appearance and condition of the skin. The other forms of vitamin C tend to have a much lower potency and don’t get converted by the body to L-ascorbic acid as readily. This seems to not be the case for tetrahexyldecyl ascorbate. 

The other issues with L-ascorbic acid products are that they are often acidic, highly unstable, and can only be formulated in a water base. 

What are the Best Skin Care Products of 2024?

Unlike pure vitamin C products and serums, tetrahexyldecyl ascorbate is lipid or fat-soluble which means it dissolves in oil. Studies have suggested that tetrahexyldecyl ascorbate may penetrate better into the skin due to the fatty acid composition of its structure. 

The benefit of tetrahexyldecyl ascorbate compared to L-ascorbic acid is that it is far more stable, less irritating, and can be easily formulated into oil-based products. 

Tetrahexyldecyl ascorbate also pairs well with other forms of vitamin C such as L-ascorbic acid, mineral ascorbates, calcium ascorbate, magnesium ascorbate, and ascorbyl palmitate. It also can be used alongside or combined with retinol as well. 

Tetrahexyldecyl Ascorbate Ingredient Review

Tetrahexyldecyl Ascorbate

the good: Tetrahexyldecyl Ascorbate is a stable and less irritating form of vitamin C which may help to improve the appearance of hyperpigmentation, minimize the signs of aging, and support collagen production. It can be formulated in an oil making it a more versatile vitamin C ingredient.

the not so good: Studies have indicated that tetrahexyldecyl ascorbate is able to be converted to L-ascorbic acid in the body so the skin is able to use it, however, this research is by no means exhaustive and more research is needed to fully understand its benefits.

Who is it for? All skin types except those that have an identified allergy to it.

Synergetic ingredients: Works well with most ingredients

Keep an eye on: Keep an eye out for which vitamin C ingredient is used in your product.

What Are The Benefits Of Tetrahexyldecyl Ascorbate?

In cosmetics and personal care products, vitamin C functions as an antioxidant that can protect the skin from free radicals, stimulate collagen production, and reduce hyperpigmentation.


Tetrahexyldecyl Ascorbate

Tetrahexyldecyl ascorbate has a vitamin C activity approximately equal to that of L-ascorbic acid. However, since tetrahexyldecyl ascorbate is lipid-soluble, it can penetrate the skin better than L-ascorbic acid and other water-soluble forms of vitamin C. 

Unlike L-ascorbic acid, it does not readily degrade in formulas Tetrahexyldecyl ascorbate has a neutral pH of 7, which, while above the skin’s natural pH, is far less irritating than the acidic L-ascorbic acid forms of vitamin C. 

The benefits of textrahexyldecyl ascorbate are considered to be synonymous with the benefits of vitamin C. However, it is important to note that tetrahexyldecyl ascorbate doesn’t have as much scientific literature to back up these claims as L-ascorbic acid. 



Tetrahexyldecyl ascorbate functions as an antioxidant, which means it is capable of protecting the skin from free radicals. 

Free radicals are generated from external factors such as UV light, smoking, diet and pollution. Vitamin C helps to neutralize free radicals imbalance by a process of electron transfer or donation. This is important because the harmful effects of free radicals can damage the DNA in your cells, the cell membrane, and cellular proteins, including collagen. 

When collagen within the skin is damaged, signs of premature aging can appear, such as wrinkles, lines, and sagging skin. Therefore, the ability of tetrahexyldecyl ascorbate to protect collagen makes it an ideal ingredient to include in anti-aging skincare products.



Tetrahexyldecyl ascorbate and other vitamin C ingredients are also used to support the treatment of hyperpigmentation, the appearance of dark spots on the skin. 

L-ascorbic acid interacts with copper ions at tyrosinase-active sites and inhibits the action of the enzyme tyrosinase, the main enzyme responsible for the conversion of tyrosine into melanin, thereby decreasing melanin formation. In simpler terms, It reduces the uneven distribution of melanin pigment or the molecule responsible for creating color in the skin. By decreasing the synthesis of melanin, the appearance of dark spots is reduced.

However, it is important to always remember to wear a sunscreen when treating hyperpigmentation. This is important for two main reasons. The first is that the sun can worsen hyperpigmentation. The second is that products that support the treatment of hyperpigmentation can often increase the sensitivity of the skin to UV damage. This includes products such as retinol and retinoids.



L-ascorbic acid also improves the elasticity of the skin and reduces wrinkles by supporting collagen synthesis. Suzan Obagi, assistant professor in dermatology at the University of Pittsburgh, explains to Scientific American, ‘After the age of 20, a person produces about 1 percent less collagen in the skin each year. As a result, the skin becomes thinner and more fragile with age.’ Therefore, by increasing the production of collagen, vitamin C may help to keep the skin strong, firm, and less susceptible to wrinkle formation.

Vitamin C acts as a cofactor or a helper molecule in the body’s natural collagen forming process. Studies have looked at  L-ascorbic acid’s ability to crosslink and stabilize collagen fibers.

 Vitamin C has also been investigated for its involvement in the production of a molecule called procollagen mRNA. This molecule signals the production of collagen and is responsible for signaling to the cell that collagen is needed. 

While several studies support vitamin C’s involvement in the processes that produce collagen, research is ongoing as to whether skincare products containing vitamin C have significant effects in improving visible firmness and elasticity of the skin.

Why Is Tetrahexyldecyl Ascorbate Special?



L-ascorbic acid is generally regarded to be a highly unstable ingredient and often needs special packaging or formulating to prevent it from degrading and losing potency. 

Tetrahexyldecyl ascorbate is a far more stable form of vitamin C. Like many of the vitamin C derivatives, tetrahexyldecyl ascorbate is stable in solution. 



Tetrahexyldecyl ascorbate is an oil-based ingredient which means that it is much more versatile than other forms of vitamin C that need to be dissolved in water. 

The oil-based formulation also helps to improve the penetration abilities of the ingredient. This helps to deliver its benefits to the skin.

The oil-base means that this form of vitamin C can be used in a larger variety of product types and with a greater range of other ingredients such as retinol. 



Tetrahexyldecyl ascorbate has a neutral pH which means that it doesn’t irritate the skin like many of the acidic vitamin C products. This neutral pH also adds to the stability and versatility of the ingredient as well. 

Can Tetrahexyldecyl Ascorbate Convert To L-Ascorbic Acid?

This is the most important question. If tetrahexyldecyl ascorbate doesn’t convert to L-ascorbic acid in the skin then it isn’t going to be beneficial. 

The answer is a tenative yes. It has shown that it is able to convert to L-ascorbic acid in vitro. In vitro means that it has been tested for this ability outside of the body. The ability of tetrahexyldecyl ascorbate to convert to L-ascorbic acid hasn’t been measured in the body, yet. 

This means that we only have the in vitro data to go off, which is useful and a good indicator of how it will work in the body but may not be the full picture. 

Is Tetrahexyldecyl Ascorbate Vegan?

Tetrehexyldecyl ascorbate is a vegan ingredient. It is made from sorbitol using various bioenzymatic and chemical processes. Sorbitol is derived from glucose, a natural sugar which is obtained from vegetable starch. 

While the ingredient may be vegan, always check the brand’s information on cruelty and vegan ingredients if you are looking for a vegan product.

Is Ascorbyl Palmitate Safe?

The safety of tetrahexyldecyl ascorbate has been assessed by the Cosmetic Ingredient Review Expert Panel, a group responsible for the independent evaluation of the safety and efficacfy of skincare and cosmetic ingredients. 

In their review, the Expert Panel looked at the available data on and determined that it causes no dermal irritation or sensitization. The Expert Panel reviewed the scientific data and concluded that this ingredient was safe for use in cosmetic and skincare products.

What Should You Consider When Choosing A Vitamin C Product?


Stability of your vitamin C product

L-ascorbic acid is a highly unstable molecule. It requires a water-based environment, a low pH and antioxidants to increase its ability to deeply penetrate the skin. Those conditions are important for creating a stable and active vitamin C product. It is essential to understand why L-ascorbic acid requires these conditions when choosing a vitamin C product in order to find one that is effective and long lasting. 

L-ascorbic acid has a reduced ability to penetrate the skin at its natural pH which is a result of its molecule structure. L-ascorbic acid is a charged molecule and is hydrophilic. These two characteristics mean that L-ascorbic acid will readily bind to water molecules, making it hard for the molecule to pass through the skin’s hydrophobic layers. 

Reducing the pH of a product to less than 3.5 or less makes it more acidic, allowing for L-ascorbic acid to penetrate deeper and be stable for longer.  However, reducing the pH of the product may lead to sensitization of the skin, as the natural pH of the skin is around 4.75-5.5. 

To create a more stable product that lasts longer, some formulations use different forms of vitamin C. This includes magnesium ascorbyl phosphate or ascorbyl-6-palmitate, which  are more stable at a neutral pH. However, a study conducted by Duke University Medical Center found that these two substitutes did not increase the natural vitamin C levels in the skin.

Some formulations include other antioxidants to help stabilize the L-ascorbic acid. Studies have suggested that incorporating ferulic acid and vitamin E can increase the stability and improve the product’s ability to penetrate deeply into the skin. A study published in the Journal for Investigative Dermatology found that ferulic acid stabilized the formulation and increased the protective capabilities of vitamin C to the sun’s effects.

In poorly designed products or formulations, the L-ascorbic acid can destabilize in the bottle, often leaving the product with a yellow hue. Oxidation is the process that causes this discoloration. In poorly designed formulations, the oxidation can also occur on the skin’s surface, leaving the skin with a buildup of free radicals and acidic by-products or waste. This can affect the health of the skin mantle barrier, interact with other products and hasten the aging process. 

L-ascorbic acid will only stay active in skincare products for a short period once opened. Even well-designed products will experience this, as exposure to the air will oxidize the L-ascorbic acid.  To increase a product’s longevity, look for powder formulations, products in vial form, or small product sizes. Look for products formulated with antioxidants such as ferulic acid. 



Concentration is another critical element when considering which L-ascorbic acid products would best suit your needs. Some brands advertise a high level of vitamin C in their product, such as 100% L-ascorbic acid. While it may seem appealing to have concentrated products, formulas with more than 20%  L-ascorbic acid can irritate the skin. Most dermatological studies have found that a range between 8-20% produces the best results with limited irritation. 

A study conducted by Duke University Medical Center found that the concentrations of L-ascorbic acid above 20% do not have increased skin benefits. The study determined that conversely, higher levels can negatively impact the skin’s condition. Sensitive skin types should use vitamin C products in the lower part of the range.


Synthetic or plant-based vitamin C

Occasionally brands won’t advertise the strength of the vitamin C content in the product but instead focus on the source. This lack of information regarding concentration tends to occur with formulations utilizing kakadu plum, hibiscus or plant-based vitamin C sources. The issue with plant-based sources of vitamin C is that they tend to be low in concentration and are generally unstable. The strength of L-ascorbic acid in kakadu plum is about 2% which means it cannot affect the skin in any significant way. The low concentration of L-ascorbic acid in plant-based sources and the instability of most natural sources is why most effective vitamin C products use a synthetic form of L-ascorbic acid in their formulations, including most clean beauty brands.


Vitamin C products

Many product types can deliver vitamin C to the skin, including gels, serums and powders and oils in the case of a few derivatives.

 L-ascorbic acid is a water-soluble molecule that requires a low pH and the inclusion of stabilizers and antioxidants, which means that most L-ascorbic acid formulations will be in a water base or dried form. Some are formulated in an oil base.

L-ascorbic acid delivered in gel or serums is absorbed quickly without adding extra moisturizing products which makes them suitable for oily or acne prone skin. They also work well with an established skincare routine, as they avoid disrupting a working regime. 

Powder forms of L-ascorbic acid prevent the need for many stabilizers. They reduce the risk of decreased effectiveness through exposure to the sun and air as the product becomes active only when mixed with water.


Other types of vitamin C

The type of vitamin C often varies between formulations. As a vitamin C source, L-ascorbic acid is the most well-researched source and the source that has shown the most benefits to the body. Other forms of synthetic vitamin C used in skincare are mineral ascorbates, calcium ascorbate, magnesium ascorbate, ascorbyl palmitate or tetrahexyldecyl ascorbate.  The type of vitamin C and the type of product can have a significant effect on the efficacy of the product.

Studies have indicated that tetrahexyldecyl ascorbate might equal L-ascorbic acid in terms of effectiveness. Tetrahexyldecyl ascorbate is an oil-soluble form of vitamin C that works alongside other products such as retinol. In a review conducted by the Cosmetic Ingredient Review, evidence indicated that tetrahexyldecyl ascorbate is more stable in solution, less irritating and able to penetrate deeper into the skin, making it a promising vitamin C treatment.



Al-Niaimi F, Chiang NYZ. Topical Vitamin C and the Skin: Mechanisms of Action and Clinical Applications. J Clin Aesthet Dermatol. 2017;10(7):14-17.
Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143-146.



Carrot & Stick

Carrot & Stick takes a tough love approach to skincare. What does this mean? It perfectly balances the power of plants with innovative science, offering the best of both worlds. Read More


The philosophy of Formulyst is long-term and effective skincare, rather than covering up any imperfections. The comprehensive line of products tackles everything from wrinkles to dark spots and dry skin. While some brands rely on unnecessary fillers and scents, Formulyst focuses on ingredients that help create results, such as vitamins, minerals and antioxidants. Read More

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