With injectables on the rise — over 7 million people got Botox last year and nearly 3 million got fillers, according to the American Society of Plastic Surgeons — it's no wonder the beauty world is so obsessed with bottling up the results for your skin-care routine. The Minus Serum, from Korean beauty brand Private Doctor, promises to do just that.
Minus Serum, and the newly launched K-beauty brand behind it, Private Doctor, is pretty big news in the skin-care world. For starters, it's basically a bottled version of Kybella — the active ingredient of which is called deoxycholic acid. When injected, it dissolves fat. Kybella is currently approved by the Food and Drug Administration to smooth fat on chins (though plastic surgeons have mixed feelings about how well it works).
The idea is that a similar active ingredient, called sodium deoxycholate, can do the same thing topically as a Kybella injection. "Our sodium deoxycholate complex was researched for its proprietary functions and aid in removing underlying fat and cellulite while producing collagen in its absence," Sang Hoon Park, founder of ID Hospital in South Korea, creator of Minus Serum, tells Allure. In theory, the result is the younger, sculpted effect that you're typically only able to get by going under the needle.
For sodium deoxycholate to work topically, the serum has to penetrate deep enough into the skin — deeper than your traditional active ingredients go — so, Minus Serum uses a cutting-edge technology that acts like teeny, tiny topical needles. The brand's "micro-tingling spicules," aka microscopic needles that are harvested from a hydrolyzed sponge, work sort of like a built-in microneedler, Park explains of the serum's formulation.
Similar microneedle-like technology is starting to show up in other skin-care products as well — specifically in acne patches, Ginger King, a cosmetic chemist tells, Allure.
"The purpose of any microneedle is to help penetration of the active ingredients," she explains. "They help drive in the actives deeper and also achieve more of a time released effect."
So, wait, how exactly does this work? "Spicules stimulate the regeneration of the skin with very thin needles, filling the pores with active ingredients to help reach the skin deep into the dermis," Park explains
Minus Serum also contains Lactobacillus ferment, a probiotic that helps the formula absorb into your skin. "Studies evaluating the skin benefits of both oral and topical probiotics are limited, but suggest a positive effect," Sejal Shah, a board-certified dermatologist in New York City, tells Allure. "Probiotics can potentially benefit the skin through anti-inflammatory, antibacterial, and antioxidant properties as well restoring the skin's normal pH level.” The ferment also helps to speed up cell turnover (translation: it glows you up) and as part of this cell turnover, the spicules are naturally shed with your dead skin cells after 72 hours.
Now for the big question: The serum sounds super science-y, but are the claims of the injectable-in-a-bottle legit? The independent experts we spoke with say it sounds promising, but there's reason to be skeptical.
Firstly, it's up for debate whether a topical version of Kybella would have any effect. "This is something that's mostly been used for injections," says King, noting that sodium deoxycholate is used in some cellulite-reducing creams in Asia, but topical use like this isn't common. Evidence supporting its topical use is mostly anecdotal at this point. "It's like caffeine, we know it will have some effect [on skin], but that effect is different when you ingest it versus apply it topically," King explains.
Then there's the space age spicule technology. Early evidence shows it's legit. A 2017 study published in the journal Molecular Pharmaceutics found it really can help active ingredients dig deep into your dermis for better results.
But there's one important caveat: Dermatologists are skeptical that the spicules could get the sodium deoxycholate deep enough into your skin to do any kind of noticeable contouring. "The fat layer is deep in the skin," Loretta Ciraldo, a board-certified dermatologist in Miami and co-founder of Dr. Loretta skin care, tells Allure. "I am not sure that even with the microspicules the active ingredient would penetrate deeply enough into the skin to help re-contour the face."