Vitamin C, also known as ascorbic acid, is one of the most extensively researched and most beloved ingredients in skincare. Its benefits are well documented, including powerful antioxidant protection, stimulation of collagen synthesis, and reduction of pigmentation. However, due to the instability of L-ascorbic acid (LAA) and its potential to cause skin irritation, increasing attention has turned toward more stable and skin-friendly vitamin C derivatives, such as THD Ascorbate.
THD Ascorbate vs. L-Ascorbic Acid
L-ascorbic acid (LAA) is the pure form of vitamin C and an exceptionally effective antioxidant. However, it is highly sensitive to light, heat, and air, leading to rapid oxidation and loss of efficacy. In addition, LAA is only stable in low-pH formulations (approximately pH 3.0–3.5), which may cause irritation—particularly for sensitive skin types.
In contrast, THD Ascorbate (Tetrahexyldecyl Ascorbate) is a lipid-soluble vitamin C derivative that offers significantly greater stability. Thanks to its lipophilic nature, it penetrates the skin’s lipid layers more efficiently, allowing it to deliver its benefits where they are most effective. THD Ascorbate remains stable at higher pH levels, reducing the risk of irritation while still enhancing antioxidant protection and supporting collagen production.
Some studies suggest that THD Ascorbate has a higher affinity for the skin due to its fatty acid component, which aids penetration. It pairs exceptionally well with other forms of vitamin C, vitamin E, green tea, and retinol, enhancing overall efficacy and anti-aging benefits.
Because it is oil-soluble, THD Ascorbate is particularly effective at neutralizing free radicals that damage skin lipids such as ceramides and cholesterol. In comparison, water-soluble ascorbic acid primarily targets different free radicals before they penetrate deeper layers of the skin. Together, these forms can offer complementary antioxidant protection.
Concentration and Efficacy
At concentrations as low as 0.1%, THD Ascorbate provides antioxidant benefits and is commonly used at levels up to 2% to support overall skin health and soothe skin exposed to environmental stressors.
For the treatment of hyperpigmentation, research indicates that 5% or higher concentrations are required to achieve optimal results. THD Ascorbate performs best in formulations with a pH of 6 or lower and has demonstrated synergistic effects when combined with other brightening ingredients such as niacinamide and licorice extract.
Notably, studies have shown that a 30% concentration of THD Ascorbate, when combined with other pigmentation-reducing ingredients, significantly improved stubborn hyperpigmentation and was even suitable for melasma-prone skin.
Among vitamin C derivatives used in skincare, THD Ascorbate stands out for its superior stability, efficacy, and skin-friendly profile.
Other Vitamin C Derivatives
Other vitamin C derivatives commonly used in skincare include ascorbyl glucoside, magnesium ascorbyl phosphate (MAP), and sodium ascorbyl phosphate (SAP). While these derivatives are more stable than LAA and are water-soluble, they generally fall short of THD Ascorbate in terms of stability, penetration, and overall efficacy. Although ascorbyl glucoside and MAP are less irritating and relatively stable, their skin penetration and visible results are often more limited.
NERDS 5% THD Ascorbate Brightening Eye Cream
One of NERDS’ innovative products is its eye cream formulated with 5% THD Ascorbate. The formula is further enhanced with 1% vitamin E, 0.5% ferulic acid, and low-molecular-weight hyaluronic acid (LMW HA).
Key Ingredient Benefits
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THD Ascorbate (5%)
A highly stable and effective antioxidant that protects against free radicals, stimulates collagen production, and helps reduce pigmentation. -
Vitamin E (1%)
A powerful antioxidant that enhances the effectiveness of THD Ascorbate, protects against oxidative stress, and supports skin hydration. -
Ferulic Acid (0.5%)
An antioxidant that stabilizes and amplifies the effects of vitamins C and E, improving their protective and photoprotective properties. -
Low-Molecular-Weight Hyaluronic Acid (LMW HA)
Penetrates deeper layers of the skin to deliver intense hydration, reduce fine lines and wrinkles, and improve skin texture and elasticity.
This advanced formulation provides optimal protection and nourishment for the delicate eye area, improving both its appearance and overall skin health.
