K18

K18 is a United States haircare company founded in December 2020 by Suveen Sahib, a technology-industry veteran, and Britta Cox, the beauty entrepreneur behind the AQUIS hair-towel brand [8]. Based in Marin County, California, the company built its products around a patented peptide it calls K18PEPTIDE and markets itself under the tagline "Biomimetic Hairscience." In 2023, the consumer-goods group Unilever agreed to acquire K18 for an undisclosed sum, folding it into the company's premium "Prestige" division [10].

The brand rose to prominence quickly, driven by a single leave-in treatment that became a social-media phenomenon and a professional-salon staple. Today K18 continues to trade as a Unilever-owned brand with an active website and a regular cadence of new launches.

The idea for K18 grew out of conversations between Sahib and Cox, who were married. Cox, having spent years in haircare, framed the problem that interested Sahib: everyday routines were time-consuming and tended to damage hair. As Sahib later put it, "From my first conversations with Britta, I became fascinated by the struggles most women (and men!) face when it comes to loving their hair." He left the technology industry to study hair biology.

Sahib worked with a research team led by Professor Artur Cavaco-Paulo at the Centre of Biological Engineering at the University of Minho in Portugal, together with Solfarcos Technologies [4]. After roughly a decade of analysing amino-acid sequences in human keratin, the group identified a peptide sequence designed to bind to damaged hair. The result was the patented K18PEPTIDE, developed through protein engineering and computational modelling intended to mimic hair's natural structure — the origin of the "biomimetic" label.

There is no standalone English Wikipedia article for K18, and the company's own website does not state a founding year; the December 2020 date is drawn from trade and editorial coverage, which is consistent across sources [8]. The brand appears in Wikipedia only within the list of Unilever-owned brands, which records the ownership but gives no founding date [13].

K18 launched its first product, an in-salon professional repair service, in December 2020. About a year later it released the consumer product that would define it, the Leave-In Molecular Repair Hair Mask, in partnership with Sephora. Within 18 months of launch the company says it reached 20,000 salons across more than 100 countries [8].

By 2023 the brand had become a notable growth story in prestige haircare. Industry coverage at the time documented more than 20 billion TikTok views associated with the brand, 45 million US dollars in funding, and 87 percent year-over-year growth [8]. That same year, Unilever announced its agreement to acquire the company.

K18 is owned by Unilever, which announced an agreement to acquire the brand in 2023; the transaction was expected to close in the first quarter of 2024, and the financial terms were not disclosed [10]. Unilever placed K18 within its Prestige portfolio. Vasiliki Petrou, then chief executive of Unilever Prestige, said the company was "thrilled to continue to grow our Unilever Prestige portfolio in high growth premium spaces with the addition of K18."

Within Unilever, K18 sits alongside other beauty and personal-care brands the group owns, including Dermalogica and Murad in the premium segment and broader names such as Dove and TRESemmé. Commentators on cruelty-free certification note that while Unilever as a whole does not hold cruelty-free status, K18 maintains its own Leaping Bunny certification.

K18 describes itself as a "biology-first" haircare brand. According to the company, "everything we do starts with biology," and it uses synthetic biology and biomimetics — which it defines as drawing inspiration from solutions found in nature — to address hair concerns "from the inside out." A recurring theme in its messaging is doing more with less: the brand argues for fewer steps, fewer ingredients and less time, and frames excessive product use as a source of both hair damage and waste.

This positioning extends to how the company discusses sustainability. K18 says its products are "powered by biotech — not natural resources," and that concentrated formulas are meant to reduce overconsumption. The company states that it is certified Plastic Neutral by Plastic Bank. It also strikes a notably cautious tone, writing that it believes "in being open about what we can do and what we can't" and describing its current efforts as "only a stepping stone."

The brand is positioned in the prestige price tier and reaches customers through multiple channels, including professional salons, Sephora and its own website. Editorial coverage has characterised it as an aspirational, professional-grade name — Refinery29 called it an "if-you-know-you-know brand name" with a following among hairstylists, colourists and celebrities such as Hailey Bieber [9].

K18's hero product is the Leave-In Molecular Repair Hair Mask, a leave-in treatment the company says works in four minutes. Its wider range includes the Molecular Repair Hair Oil, the PEPTIDE PREP detox shampoo, the DAMAGE SHIELD pH protective shampoo, the AirWash dry shampoo and the TripleBright purple shampoo aimed at blonde hair.

The line is built on several proprietary technologies. The central one, K18PEPTIDE, is described as repairing hair "at a molecular level across multiple types of bonds including polypeptide chains and disulfide bonds," and the company says it reverses damage from bleach, colour, chemical services and heat. Other named technologies include odorBIND, used in the AirWash dry shampoo, which the brand says draws on DNA databases to mimic strong olfactory systems; resilicore, a heat-shielding ingredient said to penetrate into the hair's core; and a triple-action system in the TripleBright shampoo. The company's products are described as vegan and free from parabens and sulfates.

K18 holds at least one granted United States patent, No. 11,642,298, and lists several further patent applications [4]. The brand says the underlying peptide technology rests on peer-reviewed research published between 2012 and 2017 on keratin-peptide interactions.

K18's Leave-In Molecular Repair Hair Mask received an Allure Best of Beauty award in 2022 [9], and the brand's website displays Best of Beauty badges for several years. In 2023, co-founder Suveen Sahib was named Entrepreneur of the Year in BeautyMatter's NEXT awards [8].

The product's rise was closely tied to social media. Refinery29 reviewed the hair mask as "The Olaplex-Like Hair Mask Viral On TikTok," positioning K18 as a direct competitor to the bond-repair pioneer Olaplex, and reported that the brand's hashtag had accumulated hundreds of millions of TikTok views at the time of writing [9]. A #K18hairflip challenge helped push the mask to best-seller status at Sephora, and trade coverage described the product as having a cult following in the professional channel.

K18 is certified by Leaping Bunny, a cruelty-free certification program, and lists itself as 100 percent vegan [11]. Independent cruelty-free trackers also describe its products as paraben-free and sulfate-free.

K18 is an actively trading brand owned by Unilever. The acquisition was announced in 2023 and expected to close in the first quarter of 2024 [10], and the brand has since continued to operate as a Unilever Prestige submark, with an active website and ongoing product launches such as TripleBright, HeatBounce and AirWash. Its scope is global.