Vitamin C Serum with Hyaluronic Acid

Every vitamin C serum on the market is the result of a single trade-off that the formulator has to make and the consumer eventually has to live with. L-ascorbic acid — the form of vitamin C that's been studied most extensively in dermatology since the 1990s — is unstable in water, oxidizes when exposed to light or air, and only works at a pH low enough to make a meaningful percentage of users wince when they apply it. The reward for putting up with all of that is the strongest published evidence base of any topical antioxidant. The competing approach is to use a derivative form of vitamin C that converts to ascorbic acid inside the skin — more stable, gentler, formulated at a higher pH — but with proportionally less clinical evidence and somewhat less potency. Almost every vitamin C serum on the shelf falls somewhere on this spectrum, and Alpha-H's Vitamin C Serum sits squarely on the derivative side. The active here is 3-O-ethyl ascorbic acid at 10% concentration. This particular derivative — ethyl ascorbic acid — is one of the more interesting members of the family because the ether bond protecting the ascorbic acid molecule is cleaved by enzymes in the skin to release free ascorbic acid, meaning that what you're delivering really does become L-ascorbic acid once it gets to the cellular level. The conversion isn't 100% efficient and the published evidence base is thinner than for direct L-ascorbic acid application, but a body of recent research suggests the brightening and antioxidant effects are real, just somewhat smaller in magnitude than what you'd get from a 15-20% L-ascorbic acid serum like Skinceuticals C E Ferulic. The supporting cast is well chosen. Sodium hyaluronate adds a hydration layer that pure water-based vitamin C serums don't provide and helps the serum glide on without the slightly tacky feel that derivative-based serums sometimes leave. Licorice root extract contributes glabridin, a tyrosinase inhibitor that brightens pigmentation through the same mechanism as vitamin C — stacking the two creates a complementary effect on hyperpigmentation rather than relying on the ascorbic acid alone. Tasmanian pepperberry extract is a brand-signature Australian botanical that contributes some antioxidant activity, though the independent evidence behind it is thinner than the rest of the formula. The texture is one of the easiest serum experiences in the category. This is a clear, lightweight liquid that comes out of a tinted dropper bottle, spreads easily across the face, absorbs within 30-60 seconds, and leaves no residue. There's no oxidation drama — the formula stays clear throughout its shelf life rather than turning amber within weeks like a typical L-ascorbic acid serum, and the sodium metabisulfite in the formula provides additional oxidation protection. The pH is high enough that there's no sting on application even on reactive skin, which is the main practical reason most users end up choosing a derivative serum over a traditional L-ascorbic acid format. The honest weakness is the orange peel oil. Alpha-H added it for the scent and to tie into the brand's Australian botanical positioning, but it adds a real fragrance to a product that otherwise would be perfectly suitable for fragrance-sensitive users. Limonene is on the INCI as a result, and limonene is one of the more common cosmetic allergens among users with reactive skin. For users who specifically need a fragrance-free vitamin C serum, this isn't the right pick — Naturium Vitamin C Complex 12% or Geek & Gorgeous C-Glow are derivative-based alternatives that skip the citrus oil. The other consideration is value. At sixty-five dollars for 25ml, Alpha-H is asking a luxury-tier price for a derivative-based serum at a moment when comparable formulas from Naturium, Geek & Gorgeous, The Inkey List, and The Ordinary deliver similar ethyl ascorbic acid concentrations for under twenty dollars. The premium reflects the brand's established reputation, the inclusion of licorice and the brand-signature pepperberry, and the more polished texture, but it doesn't reflect a fundamental difference in the active itself. If you've used the budget alternatives and felt underwhelmed, the upgrade may be worth it. If you've never tried a derivative-based vitamin C, starting with a budget option to see how your skin responds is the smarter play. As a brand, Alpha-H has earned its position over nearly three decades of clinical Australian skincare. The Vitamin C Serum is a competent execution of a derivative-based formula and a reasonable choice for users who want a stable, gentle, well-rounded brightening serum and are willing to pay the brand premium for it. It's not the strongest vitamin C serum on the market and it's not the cheapest, but for users who fall in the middle of the trade-off spectrum, it's an easy serum to live with and a reasonable contributor to a daily morning routine.

Formula

The Science

The science of topical vitamin C is divided cleanly into two camps. L-ascorbic acid is the most-studied form and the only one whose clinical efficacy has been demonstrated repeatedly in randomized trials going back to the 1990s. A 1996 study by Pinnell and colleagues in the Journal of the American Academy of Dermatology established the 8-15% concentration range that has become the standard for clinical brightening serums, along with the requirement for low pH (under 3.5) for the molecule to penetrate the skin in unionized form. The trade-off is the well-documented instability — L-ascorbic acid oxidizes rapidly in water, especially in the presence of light and air, which is why traditional vitamin C serums turn from clear to amber within weeks of opening. Vitamin C derivatives were developed to address the stability problem. 3-O-ethyl ascorbic acid is one of the more recent additions to the family and is structurally distinct from earlier derivatives like ascorbyl glucoside and magnesium ascorbyl phosphate because the ether bond at the third carbon position blocks the oxidation pathway entirely. A 2017 study in the Journal of Investigative Dermatology examined the percutaneous absorption and intracellular conversion of ethyl ascorbic acid and demonstrated that the molecule both penetrates the stratum corneum effectively and is cleaved by skin enzymes to release free ascorbic acid. Subsequent in vitro and small clinical studies have shown brightening and antioxidant effects, though the body of evidence is significantly smaller than for L-ascorbic acid. The licorice root extract in this serum contributes a separate validated mechanism. Glabridin, the active flavonoid in licorice, is a documented tyrosinase inhibitor with multiple published studies demonstrating its effect on melanin synthesis. Combining glabridin with vitamin C in a single formula creates a complementary attack on the pigmentation pathway that's more comprehensive than either ingredient alone, which is the formulation logic behind including it.

Dermatologist Perspective

Dermatologists generally view vitamin C derivatives as a reasonable alternative to L-ascorbic acid for users who can't tolerate the irritation or instability of the traditional form. Board-certified dermatologists note that ethyl ascorbic acid in particular has the strongest derivative evidence base among the newer molecules and is a defensible choice for sensitive complexions. Clinicians typically recommend combining a morning vitamin C serum with broad-spectrum SPF, since the antioxidant works as a complement to sunscreen rather than a substitute, neutralizing the small percentage of UV-generated free radicals that get past sunscreen protection. Dermatologists also flag that derivative-based serums generally produce more subtle and slower-developing visible results than high-percentage L-ascorbic acid formulas, which is worth managing patient expectations around.

Guidance

Alpha-H was founded in Australia in 1995 by Michelle Doherty after years of working as a beauty therapist. The brand made its name with Liquid Gold, one of the first widely available at-home glycolic acid treatments, and built a clinical reputation around acid-based exfoliation. The Vitamin C Serum was added in 2018 to round out the brand's brightening lineup and intentionally chose a derivative form to deliver vitamin C activity without the irritation that put off many users on the brand's stronger Liquid Gold treatment.

About Alpha-H Established Brand (5–20 years)

Alpha-H was founded in Australia in 1995 by Michelle Doherty and is best known for its Liquid Gold glycolic acid treatment, which was one of the first widely available at-home AHA exfoliants. The brand has nearly three decades of track record in clinical skincare focused on acid-based exfoliation and brightening.

Brand founded: 1995 · Product launched: 2018

Myth vs. Reality

Myth

Vitamin C derivatives don't work — only L-ascorbic acid is real vitamin C.

Reality

3-O-ethyl ascorbic acid converts to ascorbic acid in the skin and has been shown in studies to deliver measurable brightening and antioxidant effects. It's not as well-validated as L-ascorbic acid but it's far from inactive.

Myth

If your vitamin C serum doesn't sting, it's not working.

Reality

The sting from L-ascorbic acid serums comes from the low pH required for stability (pH 2.5-3.5), not from the vitamin C itself. Derivative-based serums work at higher pH and don't produce the same surface irritation while still delivering the active ingredient to the skin.

FAQ

Common Praise

"Stable formula doesn't oxidize like ascorbic acid serums"

"Visible brightening within a few weeks"

"Doesn't sting reactive skin like L-ascorbic acid"

"Pleasant orange scent"

Common Complaints

"Pricey for a derivative-based vitamin C"

"Orange oil triggers fragrance-sensitive users"

"Smaller 25ml size for the price"

"Less potent than 15-20% L-ascorbic acid"

Notable Endorsements

Beauty editor pick at multiple Australian publications

Appears In

best vitamin c serums best vitamin c for sensitive skin best stable vitamin c serums best brightening serums

Related Conditions

hyperpigmentation dullness sun damage dark spots

Related Ingredients

vitamin c hyaluronic acid licorice root