This Dupe of a Cult $148 Vitamin C Serum Just May Be the Smartest Swap in Skincare

From our industry colleagues at SkinSkoolBeauty.com, a great comparison overview of our Reviv-C 36% Vitamin C Serum with Allies of Skin 35% Vitamin C Perfecting Serum:

If you're the type who reads ingredient lists before buying (and if you're reading this, you probably are), you've almost certainly come across the brand Allies of Skin. It's become a cult favorite for its "supercharged" approach: clinical-grade concentrations of proven actives, fewer products, bigger results. Even in the fickle world of skincare, it is one of the most universally respected brands.

Their 35% Vitamin C Perfecting Serum is a fairly new addition. It's a waterless, high-potency formula with a genuinely devoted following for its brightening, glow-giving results — without the irritation you'd expect at that concentration. The catch? At $148 for 30mL, it's the kind of product that makes your skin look amazing and your bank account look... less so.

Enter the Reviv-C 36% Vitamin C + Phloretin Ferulic Kakadu Serum. We've been meaning to do the detailed head-to-head on this one for a while now, and when we finally sat down to compare the ingredient lists, we were pretty surprised by what we found. It appears to be a remarkably similar core formula — and in some ways a more comprehensive one — at a fraction of the cost.

Key Takeaways

  • Both serums use the same dual-Vitamin C approach (Ethylated L-Ascorbic Acid + THD Ascorbate) in a waterless, DMI-based formula. The core architecture appears nearly identical.
  • At $79 for 60mL versus $148 for 30mL, Reviv-C comes in at roughly one-quarter the cost per milliliter — a dramatically more affordable option for what appears to be a comparable (and arguably more feature-rich) formula.
  • They share several supporting antioxidants (Superoxide Dismutase, Glutathione) and even the same preservative system.
  • Reviv-C includes a significantly broader antioxidant network with additional ingredients like Phloretin, Ferulic Acid, multiple forms of Vitamin E, Astaxanthin, and Kakadu Plum — none of which appear in the Allies of Skin formula.

The Core Vitamin C System: Strikingly Similar

Both serums take the same fundamental approach to delivering Vitamin C. Rather than relying on a single form of the vitamin, each product combines two complementary types:

Ethylated L-Ascorbic Acid (3-O-Ethyl Ascorbic Acid) is the star of both formulas. This is a modified form of pure Vitamin C that appears to offer greater stability and better skin penetration than traditional L-Ascorbic Acid. It's considered a "direct-acting" derivative, meaning it begins working upon contact with skin without requiring enzymatic conversion.

Tetrahexyldecyl Ascorbate (THD Ascorbate) is the second Vitamin C form in both products. This oil-soluble derivative is believed to penetrate the lipid layers of the skin more effectively, complementing the water-compatible ethylated form nicely.

Allies of Skin is transparent about their split: 25% Ethylated L-Ascorbic Acid + 10% THD Ascorbate = 35% total. Reviv-C claims 36% total but doesn't publicly break down the ratio between the two forms. Based on ingredient list order, it appears that the ethylated form is present at a higher concentration than the THD Ascorbate in both products.

The Base: Both Waterless, Both Using DMI

This is probably the most telling similarity. Both serums are anhydrous (waterless) formulas — a deliberate choice. Water accelerates the oxidation and degradation of Vitamin C, so removing it from the equation is a meaningful way to boost shelf stability and potency.

Both formulas also use Dimethyl Isosorbide (DMI) as a key carrier solvent — a corn sugar-derived penetration enhancer that helps dissolve and transport active ingredients across the skin barrier, while also reducing irritation from potent actives.

Additionally, both contain Ethoxydiglycol, another penetration-enhancing solvent, and Isodecyl Neopentanoate, a lightweight emollient that contributes to the silky texture both brands describe.

Shared Supporting Ingredients

The overlap doesn't stop at the Vitamin C system. Both serums include:

  • Superoxide Dismutase — a powerful antioxidant enzyme that neutralizes superoxide radicals. Allies of Skin positions this as part of their "next-generation antioxidant complex," and Reviv-C includes it as well.
  • Glutathione (L-Glutathione) — often called the body's "master antioxidant." Its presence in both formulas suggests the formulators understand that Vitamin C works best within a network of antioxidants that can help regenerate and support one another.
  • Even the preservative system is essentially identical: both use Phenoxyethanol, Caprylyl Glycol, and Ethylhexylglycerin — a well-regarded, effective blend commonly found in higher-end skincare.

Where Reviv-C Goes Further

This is where the comparison starts to tip in Reviv-C's favor — at least on paper. The Reviv-C formula includes a number of additional active ingredients simply absent from the Allies of Skin version:

  • Phloretin — a polyphenol antioxidant derived from apple bark, studied for its potential to enhance the penetration and efficacy of Vitamin C. Worth noting: with Phloretin at 2.0% and Ferulic Acid at 0.5%, Reviv-C also appears to overlap with key actives found in SkinCeuticals Phloretin CF and CE Ferulic — two of the most iconic (and priciest) Vitamin C serums on the market. In a way, this formula seems to be pulling from multiple playbooks at once.
  • Ferulic Acid — best known from research suggesting that combining it with Vitamins C and E may significantly boost photoprotection. Its inclusion here appears to be a deliberate effort to create a synergistic antioxidant network.
  • Vitamin E (in multiple forms) — Reviv-C includes Vitamin E Acetate, Tocopherol, and Tocotrienols. The interplay between Vitamins C and E is well-documented; they appear to regenerate each other, potentially extending the antioxidant protection of both.
  • Astaxanthin — a carotenoid antioxidant sometimes described as one of the most potent found in nature, offering protection against both UV-induced and pollution-related oxidative stress.
  • Alpha Lipoic Acid — a versatile antioxidant that is both water- and fat-soluble, allowing it to work across different layers of the skin, while also helping regenerate other antioxidants including Vitamins C and E.
  • Kakadu Plum (Terminalia Ferdinandiana Fruit Extract) — an Australian superfruit reported to contain one of the highest natural concentrations of Vitamin C on earth, along with additional phytochemicals.
  • Pomegranate Seed Oil — rich in punicic acid, a fatty acid with anti-inflammatory and skin-conditioning properties.
  • Lycopene, Lutein (Xanthophyll), and Beta-Carotene — a trio of carotenoid antioxidants that work together to neutralize different types of free radicals across different environments within the skin.

In short, Reviv-C delivers a substantially more complex antioxidant network. Allies of Skin takes a more streamlined approach with their Superoxide Dismutase + Glutathione complex, but the total number of supporting actives is considerably smaller.

The Texture and Experience

Both brands describe a nearly identical user experience: a waterless serum that feels oily or slippery for a few seconds before absorbing and drying down. Both emphasize that the products are oil-free despite the initial feel, and both recommend application on damp skin for best results.

One notable difference: Reviv-C notes that users may detect a citrus-like scent and a characteristic "wet pennies" aroma from the ferulic acid — neither of which is present in the Allies of Skin version, since it doesn't contain ferulic acid.

The Price: This Is Where It Gets Wild

Let's talk numbers, because this is where the comparison gets really hard to ignore.

Allies of Skin's serum costs $148 for 30mL — about $4.93 per mL. Reviv-C's serum costs $79 for 60mL — roughly $1.32 per mL. That's nearly four times the value. When you factor in that Reviv-C appears to offer a more comprehensive formula, the price difference is pretty striking.

We asked the brand if they could offer our readers a discount, and they came through with an exclusive code: SKOOLc10 for 10% off the Reviv-C 36% Vitamin C Serum. That brings it down to around $71 for 60mL — which is kind of absurd value for a serum with this ingredient profile. We're not sure how long they'll keep this active, so if you're curious, sooner is probably better than later.

The Bottom Line

When you compare these two products side by side, the similarities in the core formula are hard to ignore. They share the same dual-Vitamin C approach, the same waterless/DMI base, several of the same supporting antioxidants, and even the same preservative system.

Where they differ, Reviv-C appears to offer more: a broader antioxidant network including phloretin, ferulic acid, multiple forms of Vitamin E, astaxanthin, alpha lipoic acid, Kakadu plum, and several carotenoids — all at a lower price point.

Does that make it a guaranteed better product? Not necessarily. Formulation is about more than just listing ingredients. Concentrations, stability, interactions, and manufacturing quality all matter enormously, and those aren't things we can fully assess from an ingredient list alone. But based on what we can see, Reviv-C appears to be a compelling alternative that seems to offer comparable (and potentially enhanced) value for significantly less money.

If you've been loving the idea of a high-concentration, waterless Vitamin C serum but haven't been able to justify the Allies of Skin price, the Reviv-C is worth a try.

https://revivserums.com/products/reviv-C-36-phloretin-ferulic-serum