Daye’s at-home diagnostic tampon kit screens for HPV, STIs, and vaginal infections—bringing cervical cancer prevention out of the clinic and into a patient’s own bathroom.
Daye Daye is a London-based gynecological health company that develops patented medical-grade tampons for period pain relief and at-home testing.
The tampon in question detects high-risk HPV strains that cause 99.8% of cervical cancer cases, has been peer-reviewed in the Journal of Clinical Microbiology, and was named a TIME Best Invention of 2024. Yet, Google has classified Daye’s diagnostic tampon not as a medical device, not as a diagnostic tool, but as a contraceptive.
No one, in the history of medicine, has used a self-sampling device as a contraceptive. Google’s categorization is ridiculous.
Most femtech founders hit a funding gap, a data gap, or an innovation gap.
The Gap Nobody Funds
180 Pitches For The Seed and 400 For The Series A
Daye’s founder Valentina Milanova.
Daye is a London-based gynecological health company that develops patented medical-grade tampons for period pain relief and at-home HPV, STI, and vaginal infection screening.
You’d think that a diagnostic tampon capable of helping eradicate cervical cancer deserves the same seriousness as everything else venture capital already funds. You’d be wrong.
Milanova founded Daye in London in 2017 after discovering that existing tampon manufacturers had no interest in raising their own standards. Tampons used internally required less regulatory documentation than most over-the-counter medications. No continuous quality management. No batch testing for heavy metals or microbiological content. One-time biocompatibility data, and that’s enough.
So she built her own manufacturing facility in Bulgaria, designed her own production standards, and applied for ISO 13485, GMP, and EU MDR certification—the same standards used for surgical instruments. She received FDA 510(k) clearance for her menstrual tampon and went on to develop a second-generation diagnostic tampon capable of at-home HPV and STI detection. The company has raised approximately $28 million, plus roughly $4 million in grants, according to Milanova.
Getting there required pitching 180 investors for the seed round and more than 400 for the Series A. Milanova is direct about why.
Annie Theriault, founding partner at CBIV and a Daye board member for four years, frames the same reality from the other side. “Daye does the unglamorous, capital-intensive work most of the category avoids—clinical trials, in-house medical-device manufacturing, real regulatory clearances,” she noted. “That combination is rare in femtech, and it’s what builds a durable business rather than a momentary one.”
Tatum Getty, a partner at Thena Capital, an investor in Daye, wrote that the company’s approach addresses a fundamental barrier to adoption. “Valentina didn’t ask women to adopt an entirely new behaviour; she took a product millions already know and trust and expanded what it could do,” she said. “That’s the kind of healthcare innovation that has the greatest chance of changing outcomes because it removes friction instead of creating it. Daye has paired that simplicity with rigorous clinical evidence, which is a combination we rarely see with an enormous market opportunity.”
What Investors Never Hear
Daye’s diagnostic tampon emerges from its sterile packaging—a familiar form redesigned from the inside out to meet medical device manufacturing standards.
Daye is a London-based gynecological health company that develops patented medical-grade tampons for period pain relief and at-home HPV, STI, and vaginal infection screening.
What Milanova has learned over nearly a decade is which parts of her own company to conceal in a pitch. CPT code eligibility, which Daye received last year and which opens a path to insurance reimbursement, actually frightened investors who immediately thought about a 14 to 90 day billing cycles depending on the payor. The tampon’s ongoing use in clinical trials to detect ovarian and endometrial cancer in the US and UK prompted the question “why aren’t you focused?” The medical database Daye has built from vaginal, menstrual, and hormonal health outcomes, shared pro bono with academic institutions, generated no interest at all.
The global femtech market was estimated at $39.29 billion in 2024 and is projected to reach $97.25 billion by 2030. None of that projected growth changes what an investor said to Milanova before one recent pitch meeting, a comment that encapsulates the problem. He opened by telling her she looked prettier in person than in her LinkedIn photo. She has made a deliberate decision to stop being angry about moments like that and put the energy somewhere productive. It is not a small decision.
The Machine Nobody Makes
One Company Controls Global Tampon Manufacturing
One structural fact reframes everything else in Daye’s story. Surprisingly only one company manufactures all global tampon manufacturing equipment lines. Milanova discovered this when she went looking for a production partner and found no one willing or capable of meeting her standards.
So Daye designed its own machines, built its own clean rooms, implemented gamma ray radiation for sterility, and developed batch testing protocols for PFAs, heavy metals, and microbiological content—none of which existing manufacturers required. The FDA 510(k) clearance Daye received was for a tampon unlike any previously approved: water-soluble wrapper, fully sterilized, produced to medical device standards. “We brought tampon manufacturing in house,” Milanova recounts, “and we decided we were going to ask notifying bodies and regulators to treat us as a medical device.”
A century of industry consolidation, zero R&D investment, and one equipment manufacturer. That is the baseline Daye is working against, and it explains why the capital intensity Theriault references is not a strategic choice. It was the only available path.
The Regulatory Vacuum
The FDA Has No Route For A Sterile Tampon
In December 2024, the FDA issued a warning letter to Daye, citing concerns that its CBD-infused tampon was being marketed for period pain relief, which the agency considered an unapproved modification to the cleared device. Daye voluntarily withdrew the CBD tampon from the US market. On June 11, 2026, the FDA confirmed it had reviewed Daye’s corrective actions and found they addressed all cited items. A follow-up inspection, the standard final step toward formal closure, remains ahead.
Milanova describes receiving the original letter as “one of the saddest events in the company history, because all that we have done until now is try and regulate ourselves to a much higher standard than the industry demands.”
The deeper problem, though, is the regulatory terrain that produced it. The FDA has no established pathway for a sterile tampon. Annual FDA registration fees run $90,000. Regulatory attorneys who can interpret guidelines that are often unwritten charge $750 an hour, and top firms frequently give differing advice on the same question.
The FDA’s 2024 attempt to regulate laboratory-developed tests, which would have affected Daye’s diagnostic screening business, was vacated by a federal court and formally rescinded in September 2025, creating months of uncertainty mid-launch. For context, a laboratory-developed test is a diagnostic test designed and used within a single laboratory rather than sold as a packaged kit. It is a category the FDA had long overlooked and then abruptly moved to regulate before the courts intervened.
Milanova’s proposed fix is a regulatory sandbox: a structured environment where regulators and innovators work together to develop approval pathways for devices that fall outside existing categories, sharing the cost and the evidence-building before either side commits to a formal process. She puts it plainly. “If we could have the regulator meet the women’s health innovator in some kind of a sandbox environment, that will be so hugely beneficial for the industry as a whole,” she says.
Without that, the cost of building genuine medical innovation in women’s health falls entirely on the founders who already cannot access venture capital.
The Last Mile Of Cervical Cancer
We Have The Technology. We Need The System
Daye’s diagnostic tampon achieves diagnostic accuracy comparable to clinician-collected swabs: sensitivity 82.9%, specificity 91.6%, and a 99.2% valid sample rate that outperforms both self-collected swabs and clinician samples on the last metric. The company is one of only six nationally approved NHS suppliers of STI and HPV screening services for the whole of the UK, and the only small company on that list. The National Health Service is the publicly funded healthcare system in the UK. In March 2026, Daye won the Digital Health Rewired Pitchfest, opening a potential NHS pilot at Chelsea and Westminster Hospital.
Mindy Simon, co-Director at the NHS Innovation Accelerator, notes that Daye’s model stands out for precisely the reasons that make it hard to fund. “Their approach is evidence-led, system-aware, and focused on improving access for patients who are too often overlooked.,” she says.
Only 62.7% of eligible women in the UK are adequately screened for cervical cancer, well below the NHS’s 80% target, and cervical cancer mortality is projected to rise 17% by 2030 if that gap persists. Milanova is unequivocal about what the actual obstacle is. “We have the technology. We have the qPCR test, we have the vaccine. We just need a system that will hold the patient’s hand through what is typically a very complex journey,” she says.
That system, as Daye has built it, includes tampon-based self-sampling, a nurse consultation for every HPV-positive patient, and vaccination booking for the patient and their partner. Clinical trials are running in Tanzania and Nigeria, where the burden of cervical cancer is highest globally. Milanova designed the platform to be global from the start, not retrofitted later because “True femtech innovation needs to be for everyone, and you need to design so that it can be for everyone from the beginning.”
The Fourth Wall
The funding gap, the data gap, and the innovation gap are problems a determined founder can eventually solve. Milanova spent nine years solving them. The fourth wall is different. It is the commercialization infrastructure: the platforms that suppress women’s health advertising, the investors who have already made their one women’s health bet for the year, the regulators who have no pathway for what you built, and the health systems undergoing their largest restructuring in history at the exact moment you arrive.
None of that is Daye’s fault. None of it diminishes what the company has built. Milanova is settled on the point that “Creating better solutions for women’s health is worth it. That’s what I often tell myself. If you work on something impactful with people that you genuinely like and admire, that’s enough.”
Whether the fourth wall moves is not up to her. That requires the platforms, the investors, and the regulators to decide that a diagnostic tampon capable of helping eradicate cervical cancer deserves the same seriousness as everything else they already fund.