This vitamin C cream is all the rage on TikTok: its real power isn't what you'd think

The Deep Vita C Capsule Cream from Medicube It checks all the boxes for a viral Korean beauty product: a clear gel, vitamin C capsules to mix in upon application, and a staggering 500,000 ppm of sea buckthorn water. But when you read the ingredients list in order, the star ingredient isn’t the one the marketing highlights.

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500,000 ppm of sea buckthorn water: what the number hides

The first ingredient is indeed sea buckthorn water (Hippophae rhamnoides water), listed at 500,000 ppm, or 50 %. The number is impressive, but it needs to be interpreted: 50 % of sea buckthorn water is not the same as 50 % of concentrated extract. A plant water is, above all, an aqueous phase containing a few compounds from the plant. So I wouldn’t judge the cream based on this figure alone.

What comes right after that speaks volumes.

A formula built around humectants

In second place: glycerin, one of the most well-documented humectants in cosmetics. In third place: niacinamide. Then comes an almost uninterrupted list of hydrophilic ingredients: methylpropanediol, propanediol, 1,2-hexanediol, butylene glycol, dipropylene glycol, and pentylene glycol.

The entire first half of the INCI list is dominated by water and humectants—ingredients that attract and retain water in the stratum corneum. And the detail that defines the product’s profile: the first true fatty ingredient, caprylic/capric triglyceride, doesn’t appear until the 10th position. This is almost the opposite of rich creams, where occlusives and fatty ingredients occupy the top spots right from the start.

Niacinamide vs. Vitamin C

Marketing Speaks vitamin C. For me, it’s the niacinamide listed in the 6th position that catches my attention. It’s a very versatile active ingredient: it supports the skin’s barrier function and helps even out skin tone and reduce the appearance of dark spots. For a skincare product that promises radiance and anti-dark spot benefits, seeing it listed so high up makes perfect sense.

She’s not alone: further down the list is alpha-arbutin, an active ingredient that effectively targets dark spots by acting on the tyrosinase pathway. Niacinamide + alpha-arbutin—we’re starting to see a solid strategy for fighting dark spots.

Five forms of vitamin C… but very low on the list

Medicube heavily promotes its various forms of vitamin C: sodium ascorbyl phosphate, ascorbyl glucoside, 3-O-ethylated ascorbic acid, ascorbic acid, ascorbyl palmitate, plus a hybrid derivative, propyl ascorbyl hyaluronate.

On paper, it looks spectacular. In the INCI list, however, it’s much less impressive: the first of these derivatives appears only after alpha-arbutin, and pure ascorbic acid is listed even further down. Five forms of vitamin C do not necessarily mean a high concentration of vitamin C. I prefer a well-formulated form at an appropriate dose to a collection of derivatives whose main purpose is to display a number on the packaging.

A blend of antioxidants to support your health

The formula includes ferulic acid, tocopherol (vitamin E), ubiquinone (coenzyme Q10), beta-carotene, rutin, and several vitamins. That’s generous, but all these ingredients appear very low on the list: I see them as complementary active ingredients, not as the cornerstones of the product’s effectiveness. The real stars remain glycerin, niacinamide, and the humectant base, complemented by alpha-arbutin.

What about anti-aging?

The brand name evokes elasticity, and the product does indeed contain adenosine, a staple of Korean anti-aging skincare. However, it’s not a major anti-aging treatment: it doesn’t replace a retinoid. On the other hand, by deeply hydrating the stratum corneum, it can quickly make the skin smoother and plumper and visually reduce the appearance of fine lines caused by dehydration.

For which skin type?

That's where the ingredient list comes in handy.

For oily skin, it’s more effective than its «capsule» concept might suggest: the first fatty ingredient is listed in the 10th position, it has a highly moisturizing base, and you can increase the gel content to lighten the texture.

For normal to oily skin, this is undoubtedly the most balanced formulation: plenty of humectants, without an excess of oils.

For normal to dry skin, I have mixed feelings because it’s sorely lacking in oils.

I don't recommend it for very dry skin

What I like least: the scent

The formula contains fragrance. It’s not a major ingredient, but I find it unnecessary in this type of skincare product. It’s fine for normal, resilient skin; for sensitive or reactive skin, I would have preferred a fragrance-free version.

My verdict

I was expecting yet another Korean cream packed with trendy active ingredients just for show. The formulation is actually quite clever. What interests me most isn’t the claim of five forms of vitamin C, but the order in which they’re listed: a large, water-based, moisturizing base, glycerin in the 2nd position, niacinamide in the 3rd, no oils until the 10th position, followed by emollients and a well-balanced blend of active ingredients for radiance and dark spot correction.

So I see it first and foremost as an excellent moisturizer designed to boost radiance and reduce dark spots, rather than as a cream with a high concentration of vitamin C. It’s particularly well-suited for oily and normal-to-oily skin.

Scan your moisturizer

To find out if your moisturizer is right for your skin type  Download the Beauty Decoded app (iOS and Android) Scan your products, decipher their INCI listings, and compare what the packaging promises with what the formula actually contains.

The rating depends on your skin!