What Is Gleam C? Our Kakadu Plum Vitamin C Blend

Gleam C™ is Gleamin's own vitamin C blend, made from two Australian fruits: Kakadu plum and desert lime. Instead of a single lab-made vitamin C molecule, it brings vitamin C the way fruit packages it, alongside the fruits' other antioxidants. It's the vitamin C behind our Vitamin C Clay Mask.

Here's what's in Gleam C, what the science does and doesn't show, how it compares with lab-made vitamin C, and where you'll find it.

What is Gleam C?

Gleam C is a proprietary blend of two fruit extracts:

• Kakadu plum (Terminalia ferdinandiana), listed on our mask's label as Terminalia Ferdinandiana Fruit
• Desert lime (Citrus glauca), listed as Citrus Glauca Fruit Extract

"Proprietary" means the recipe is ours: which fruits we use, how we pair them and how much goes into each formula. Gleam C is the name we give that pairing, so you won't find it as its own line on an ingredient list. Look for the two fruit names instead.

Our products are made in Texas, but the Kakadu plum and desert lime in Gleam C still come from Australia, where our mask was first made. It went from concept in 2017 to launch in 2019.

Why use a botanical vitamin C blend?

The mask started with a kitchen ritual. People were mixing turmeric and vitamin C into homemade masks because they loved how bright their skin looked afterward. We wanted to keep the spirit of that ritual, with vitamin C from fruit, and make it stable, balanced and comfortable to wear.

A botanical blend has real strengths:

• It brings more than vitamin C. Fruit extracts carry a mix of compounds. Kakadu plum, for example, is rich in antioxidant polyphenols, mainly gallic acid and ellagic acid [2].
• Two fruits, not one. Each fruit has its own antioxidant mix, so the blend doesn't lean on a single source.
• It's made for a formula, not a fridge. Fresh fruit juice changes the moment it's cut, and citrus juice can irritate skin. A preserved extract can be measured and blended evenly into clay, batch after batch.

There's one trade-off, and we'd rather say it plainly. A fruit extract doesn't give you a precise vitamin C dose. The vitamin C in fruit varies with the tree, the season and the harvest. That's why we don't print a vitamin C percentage for Gleam C.

How much vitamin C is in Kakadu plum?

Kakadu plum has the highest natural vitamin C content recorded in any fruit. Researchers first reported its unusually high levels in The Lancet in 1982 [1]. Later analysis of commercially grown native Australian fruits confirmed its exceptional vitamin C content and antioxidant capacity [2].

It's a small, pale-green fruit about the size of an olive. It grows in the open woodlands of northern Australia, where it's also known as gubinge or billygoat plum. Aboriginal communities have eaten it for generations.

A number measured in fresh fruit doesn't carry over directly to an extract in a jar, so we don't quote a "times more than an orange" figure. For the full profile, read Kakadu Plum for Skin.

What does desert lime add to Gleam C?

Desert lime is a small, tart wild citrus about the size of a grape. It grows in the dry inland of eastern Australia and survives heat, drought and frost that most citrus couldn't [3]. Like other citrus, it's a natural source of vitamin C. Native Australian citrus is also studied for its phenolic compounds and flavonoids [3].

In Gleam C, Kakadu plum is the vitamin C headliner. Desert lime rounds out the blend with its own citrus antioxidants. Read more in Desert Lime for Skin.

How does Gleam C compare with lab-made vitamin C?

They're different tools, and neither wins on every count.

Pure vitamin C, L-ascorbic acid, is the most researched form, but it's fragile. It breaks down in light, air and water, and its low pH can sting. That's why most serums use stable forms made in the lab [4]:

• Sodium ascorbyl phosphate (SAP): water-soluble, gentle and stable
• 3-O-ethyl ascorbic acid: stable, and known for getting into the skin well
• Tetrahexyldecyl ascorbate (THD): oil-soluble and very gentle, a natural fit for creams and oils

Here's how Gleam C stacks up against them:

• Dose. Lab-made forms can be measured to an exact percentage. Gleam C can't, because fruit varies.
• Evidence. Most skin studies of vitamin C test purified forms in leave-on products [4][5]. Kakadu plum and desert lime are studied mainly as foods. We haven't found controlled human studies of either extract on skin.
• Extras. Gleam C brings the fruits' polyphenols and other antioxidants along with its vitamin C. A single molecule brings only itself.
• Best format. Lab-made forms shine in daily leave-on serums and creams. Gleam C gives a rinse-off mask a fruit-based source of vitamin C.

Many good routines use both, and so do we. For the bigger picture, read Vitamin C for Dark Spots.

Does Gleam C help with dark spots?

Vitamin C is one of the best-studied ingredients for a brighter, more even-looking tone. In research on topical vitamin C, it [4][5][6]:

• acts as an antioxidant, helping neutralize free radicals from UV and pollution
• interrupts tyrosinase, the enzyme that starts melanin (pigment) production
• supports collagen, which skin needs to stay smooth and resilient

Gleam C is a rich natural source of vitamin C, but it hasn't been studied on skin on its own. So here's the fair way to put it: as part of a steady routine with daily sunscreen, products with Gleam C can help skin look brighter and help dark spots look less noticeable over time. Changes build gradually over 8 to 12 weeks, and results vary.

Which Gleamin products contain Gleam C?

If you searched for Gleamin vitamin C, here's the map:

• Vitamin C Clay Mask. Gleam C is the mask's source of vitamin C. It's paired with finger lime (a third Australian citrus, listed separately), turmeric, kaolin, Hydroclay and aloe vera. It stays on for about 10 minutes, and skin looks fresher and more radiant right after rinsing. It's dermatologist tested.† See the Vitamin C Clay Mask or read Inside Our Vitamin C Clay Mask.
• Advanced Brightening Moisturizer. Our daily cream lists Gleam C as a key ingredient, alongside THD, 3-O-ethyl ascorbic acid, lilly pilly and ceramides. See the Advanced Brightening Moisturizer.

Our Superactive Serum takes the lab-made route, with 15% vitamin C from 3-O-ethyl ascorbic acid and sodium ascorbyl phosphate. Our Clarifying Brightening Cleanser uses desert lime, one half of the blend.

†Repeat insult patch test on 52 adults, supervised by a consulting dermatologist (Princeton Consumer Research, 2023). No irritation or allergic reactions were observed.

How do you use the Vitamin C Clay Mask?

1. Start with clean, dry skin.
2. Apply an even layer with the brush or your fingertips, avoiding the eyes and lips.
3. Leave it on for about 10 minutes, no longer than 15, then rinse with warm water.
4. Follow with serum and moisturizer, and wear SPF 30 or higher every morning.
5. Start once or twice a week, building up to three times if your skin is happy.

The step-by-step guide is in How to Use a Vitamin C Clay Mask. You can find the Vitamin C Clay Mask (2.5 fl oz) on Amazon.

The bottom line

Gleam C is our botanical vitamin C blend of Kakadu plum and desert lime, sourced from Australia. It brings vitamin C together with the fruits' other antioxidants, and it's the vitamin C in our Vitamin C Clay Mask. It isn't a measured dose like a lab-made form, and we don't pretend it is. We use it where fruit-based vitamin C makes sense, and stable lab-made forms where a daily measured dose matters.

References

1. Brand JC, Cherikoff V, Lee A, Truswell AS. "An outstanding food source of vitamin C." The Lancet (1982).
2. Konczak I, Zabaras D, Dunstan M, Aguas P. "Antioxidant capacity and hydrophilic phytochemicals in commercially grown native Australian fruits." Food Chemistry (2010).
3. Sultanbawa Y, Sultanbawa F, eds. Australian Native Plants: Cultivation and Uses in the Health and Food Industries. CRC Press (2016).
4. Al-Niaimi F, Chiang NYZ. "Topical vitamin C and the skin: mechanisms of action and clinical applications." Journal of Clinical and Aesthetic Dermatology (2017). PMC5605218
5. Telang PS. "Vitamin C in dermatology." Indian Dermatology Online Journal (2013). PMC3673383
6. Pullar JM, Carr AC, Vissers MCM. "The roles of vitamin C in skin health." Nutrients (2017). PMC5579659

This article is for general information and isn't medical advice. If you have a skin condition or concern, talk to a doctor or dermatologist.