Let them eat caviar?

Good morning, it's your weekly Skin-ny on all things skin. This week: whether caviar belongs on your face or your blini, three brands harnessing water from around the world and backing it with real science, Birchbox's co-founder betting your bare nails deserve a skincare routine of their own, Oh My Cream's new Paris flagship with a sauna in the basement, and the vitamin C serum sitting in every dermatologist's cabinet just got a rework. Grab your eye patches, grab your morning mug, and read on.

Say caviar and your mind goes straight to silver trays and decadent ballrooms. Whether this translates to skincare benefits is another question entirely. Strictly from an ingredient list perspective, caviar extract makes sense on paper, an egg carries proteins, omega-3 fats, vitamins A, D, E and B12, and minerals like zinc and selenium, so rubbing it on your face reads like feeding your skin dinner. La Prairie launched Skin Caviar in 1987: but 39 years of marketing isn't 39 years of evidence. The real reason caviar caught on is that it is the most expensive food most people can name, so an expensive cream feels more justified.

The research is thinner than the marketing suggests. The one human trial, published in Nutrients in 2024, showed better hydration and wrinkle scores, but participants swallowed capsules rather than applying a cream, and the authors work for the cosmetics manufacturer and caviar supplier that funded it. A 2026 study analysing caviar's proteins, funded by the caviar industry itself, found commercial extracts vary wildly batch to batch, much of it ovarian fluid scraped up alongside the eggs rather than the eggs themselves. There's also a basic size problem: caviar's proteins are large molecules, and skin is built to keep large molecules out.

So, do "caviar" products actually contain any? Usually, yes, but in trace amounts. Five products, decoded:

Three brands this week, each drawing on water from a different corner of the world and backing it with real science, rather than treating it as filler.

Nao Tsuruta, founder of Shinso, trained as an aerospace engineer and spent his career focusing on water. He worked the desalination side of Dubai's Palm Jumeirah build, then went on to help grow Japan's biggest water-delivery company. The brand's own origin story leans on Japanese folklore, a fisherman who cures his ailing wife with water from the sea's depths and a rare flower, her frailty replaced by an instant, radiant glow. Shinso's ingredient list is built around deep sea water sourced from Japan's shores, and The Essence is also paired with fullerene and EGF (epidermal growth factor), both ingredients with real Nobel Prizes behind them. It's sold through luxury spas, pharmacies and doctor's offices rather than off a Sephora counter, maintaining its luxury status while cleverly positioning itself alongside medicine, without ever claiming medical-grade status. £255 for 30ml. (Linked, not affiliated.)

Omorovicza built its whole identity on Hungary's thermal water, which inspired founders Stephen and Margaret de Heinrich de Omorovicza. Hungary sits on the thin-crusted Carpathian Basin, giving it over a thousand natural hot springs. A geological quirk the Romans turned into a bathing ritual more than 2,000 years ago, and the Turks later built grand bathhouses around it. The Deep Cleansing Mask leans on Hungarian moor mud from Lake Hévíz, plus the brand's patented Healing Concentrate, fermented from that same thermal water. The moor mud pulls out congestion while the fermented Healing Concentrate calms skin, pairing the water's detox power with an active dose of science. £85. (Linked, not affiliated.)

Built on Avène's own Thermal Spring Water, sourced from the Sainte-Odile Spring at Avène-les-Bains in the south of France, plus a patented postbiotic called C+Restore that speeds up skin's own recovery. The spring's reputation dates back to 1736, when the Marquis de Rocozel's horse, suffering from a skin condition, was turned loose near the water and turned up months later healed. Avène's own count puts it at 48 different uses, gentle enough for the whole family, infants included. A prime example: right after a treatment, or when your skin's just been extra angry lately. Pair it with a hydrating serum, slather on the cream before bed, and you've replicated a decent chunk of what an in-clinic barrier treatment does, for less than a tenner. £9.95 for 40ml, less than most people's coffee order for the week.

Pro tip: reach for La Roche-Posay's Cicaplast Baume B5+ instead if you want something lighter, or you're buffering a retinoid, £11 for 40ml, less weight on skin. (Linked, not affiliated.)

The 22-SKU line skips polish for a lactic-and-glycolic-acid exfoliant, a nail serum and a finishing gel oil, developed with a formulator who holds a PhD in keratin studies, plus a set of nail tools built around the same routine. It launched direct-to-consumer on 24 July, with a major retail partner following next month.

Why it matters: It treats nails with the same care you'd give your skin everywhere else, another sign the "skinification of everything" has room to grow past the face.

Kiehl's teamed up with Go Greek on a limited-edition Better Summer Swirl cup, handing out samples of its Better Screen UV Serum SPF 50+ (£42) from co-branded carts. Korres, whose whole origin story starts with dabbing cold Greek yogurt on sun-stressed skin, built its own Go Greek collab around a Greek Glow bowl and a sample of its Greek Yoghurt Probiotic Foaming Cream Cleanser (£21.50). Saltair went furthest, producing 25,000 custom Coral Coast bowls for its own Go Greek tie-in, which sold out within two weeks.

Why it matters: Frozen yogurt reads as an indulgence that still counts as self-care, exactly the kind of business opportunity beauty brands chase. It's visual and shareable enough to go viral on its own, and it comes wrapped in an easy summer association.

The new 2,690-square-foot, three-storey space on Rue du Vieux Colombier stacks roughly 100 brands on the ground floor over a basement built for infrared sauna and cold plunge, with a juice and supplement bar, an activewear corner and a treatment room upstairs.

Why it matters: It's part of a wider wellness shift, retail built to feel like a spa visit rather than a scrum for the last tester on the counter. Oh My Cream's now at 40 stores in France, 6 in London and 2 in Belgium, with sales pushing toward €50 million and climbing 20% this year.

SkinCeuticals just reformulated C E Ferulic, the serum that dermatologists, beauty editors and cosmetic chemists have quietly agreed is the holy grail of vitamin C for twenty years. The original, 15% L-ascorbic acid, 1% vitamin E and 0.5% ferulic acid at a low pH, was covered by a patent from 2005, and expired in March 2025.

The new version keeps the original trio and adds 0.3% carnosine, a dipeptide linked to fighting fine lines. It also adds 1% endophytol, a dandelion root extract the brand credits with calming and anti-pollution effects, both aimed at cellular longevity rather than just brightening. It's a tell that prevention over correction isn't just here to stay, it's becoming the new standard in skincare, showing up in reformulations of the industry's most established products, not just in new launches chasing the word.

SkinCeuticals is already calling the new formula "double patent-pending", covering the antioxidant technology, and also strategically signaling that once again no one does it quite like them. No clinical data on this exact version has been published yet. Worth a watch-and-see rather than taking on faith, even from a brand with this much history behind the original.

£169 is quite the price tag, which is exactly why dupes chasing SkinCeuticals' formulation have been cropping up for years. So what does a dupe actually mean? Less money, the same actives at the same or similar percentages, though the stabilisation, pH and texture can vary, and some throw in an extra active or two to try to stand out. A dupe copies the actives list, not the twenty years of research behind C E Ferulic, which is really what you're paying for. If your skin's happy with whichever bottle you've chosen, that's still the right answer.

The closest dupes that chased SkinCeuticals' formulation as close as possible without getting sued:

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