The Instagram post, precision-guided by sex and age, had zeroed in on its target. Yuchen Tu is a conservatory-trained viola player from Chongqing, China, a lover of science fiction, and an aspiring member of the US Army Reserve Officer Training Corps. She’s exacting and intense, with sky-high standards. And late last spring, just after her 24th birthday, she realized she might be the perfect candidate to freeze her eggs—for free.
Tu goes by Sue, a name she likes because it reminds her of the 2024 body horror film The Substance, whose protagonist tortures herself in pursuit of youth and beauty. To prequalify for free egg freezing, all Sue had to do was take a two-minute quiz. “Not everyone can pass this exam,” she remembers thinking. “Oh, it seems like a competition.”
Sue passed, as have thousands of young women allured by the promise of a company called Cofertility. “The best time to freeze your eggs is when you can least afford it,” goes the company’s mantra, uttered on repeat by its public face and CEO, onetime Uber employee Lauren Makler. Thus was born Cofertility’s mission: to help women like Sue, who had just received her master’s degree in classical music and was preparing to embark on a second bachelor’s, preserve their future fertility for zero dollars.
But in the United States, there’s no such thing as free health care. Instead of paying to freeze and store her eggs with money—the going rate in New York City, where Sue lives, is about $18,000—she would use a currency she already had in abundance: the eggs themselves. Cofertility’s clients must, in the company’s words, “donate half of the eggs retrieved to intended parents that need the help of an egg donor to have a baby.” It’s a model called egg sharing, and it hadn’t been commercialized widely in the US until Cofertility came along. The Los Angeles–based company launched in 2022, dubbing itself “a new kind of human-centered fertility ecosystem.”
Sue perused Cofertility’s website, clicking through text boxes of deep, soothing teal, optimistic light green, a steady purple, and an urgent orange. She was invited to a meeting almost immediately after passing the test, and within days she was video chatting with an employee who gushed that Sue would be doing the responsible thing for her own future while fulfilling the dreams of a desirous family. In the background of Sue’s Zoom, the Cofertility employee spied a piano and asked if she could record Sue playing. It’d be enticing to prospective parents who might want the eggs of a piano prodigy.
Sue found the proposal preposterous. Her instrument is the viola, not the piano, as anyone who read her file would know. Sue declined, and recalls the saleswoman’s disappointment. The tone of the interaction was “weird,” Sue thought—a combination of overeager and saccharine. But she was curious about the company, and she wanted to find out more about the booming business of fertility care that a 24-year-old might not need for years, if ever. On July 29, 2025, Sue signed a contract with Cofertility.
The age-old pressure to reproduce has morphed into a biohacking imperative with a feminist sheen. Career-oriented young women who have no imminent plans to become mothers and no substantiated reason to doubt their abilities to procreate have succumbed to the messaging that, if they don’t want to miss out on this primal rite, the time to take charge of future baby-making opportunities is now. “Three in five Gen Z women are concerned about their fertility,” Makler said on a podcast last year, citing a survey by a network of California fertility clinics. The oldest members of that generation are about to turn 30.
A donor-freezer I’ll call Mona was 25 when she applied to use Cofertility. She had just read a book called The Defining Decade, which argues that the decisions people make in their twenties shape the course of the rest of their life. Fertility was one of those critical areas, and when Mona found Cofertility online, she liked how the company seemed to put reproduction within her control.
Control is a hot commodity in an exploding market, where venture capital has sunk its teeth into new startups boasting AI-backed conception-probability calculators or promising money-back guarantees for frozen eggs that, in the words of one startup, “do not result in a live birth.” More established clinics and national chains advertise monthly payment plans—then get bought up by private equity. All these endeavors involve an exchange of cash for egg freezing, and that’s where Cofertility—which hit $16 million in funding after a Series A round announced last year—offers a unique intervention.
In a more traditional cash-pay egg-freezing model, clients—who tend to skew older—work with their own doctors and clinics, keeping their medical information locked behind the gates of HIPAA. But Cofertility is not a medical provider; it’s a middleman, and it needs to cover the cost of egg freezing by selling aspiring parents on profiles that show their donors’ height, weight, racial background, family medical history, and self-administered aptitude ratings. “It’s like Tinder,” one intended parent tells me. You swipe through profiles and try to envision your future as defined by those genes.
Cofertility calls its egg-sharing program Split, available to those who start between the ages of 21 and 33 and check the right biological boxes. The company further splits Split into two models, Fresh and Frozen, which Mona and Sue respectively chose. With the newer Frozen model, donor-freezers “cycle first, match later,” as the company puts it. Cofertility fronts the payment for medical and psychological screening, hormonal stimulation, and surgery—typically across two cycles—then makes up the cost by selling eggs from the first batch to intended parents.
The Fresh model is the flagship: It can be done with just one cycle, and donor-freezers match with intended parents before they carry it out. Mona matched with a couple I’m calling Alexis and Greg, who “adored her to no end,” as Alexis says. They met once over Zoom and felt they could be friends. Cofertility mediated all their communication.
The intended parents put up the cash, covering the course of hormonal medications a donor needs to inject herself with for up to two weeks before her egg retrieval, plus genetic testing and psychological screening to ensure the match can proceed. Intended parents have a rough sense of how many eggs they might get, because they see the donor’s level of anti-Müllerian hormone, or AMH, a commonly used indicator of ovarian reserve. Doctors then track the development of the donor’s ovarian follicles, fluid-filled sacs that house maturing eggs.
But the only way to know how many eggs you’ll get is to go in and get them. Using a needle inserted transvaginally on a wand, a doctor punctures each follicle and sucks up the fluid that the hormone regimen triggered them to produce. The more hormone-fattened sacs there are, the more eggs—but also the riskier the procedure, because each wet little bundle increases the weight and volume of the ovary, and an ovary that gets too plump on hormones can twist and cut off its own blood flow in a suicidal gonadal maneuver known as ovarian torsion. Mona recalls feeling comforted by Cofertility’s promise that she could back out at any point, up until her final hormone injection. But the kind of ovarian overreaction that might prompt someone to cancel her cycle could land her in the emergency room, possibly minus an ovary. (According to one donor’s contract, she’d also have to pay her own medical costs. The company says that provision has since been removed.)
On Cofertility’s Instagram, women hike, swim, and “manifest” career milestones between self-administering “super easy” hormone injections. If all goes according to plan, there will be some number of eggs on offer that get halved and distributed to the person who produced them and the person who paid. (If there’s an odd number, the party footing the bill takes the extra.) Intended parents using fresh eggs often try to fertilize and implant embryos right away. The donor puts her portion on ice, on the beneficiaries’ dime, for up to 10 years.
Cofertility’s donors route their blood work and other medical updates through company liaisons referred to as “member advocates.” Sue was in near-constant contact with hers, a young woman who peppered her correspondence with smiley faces—a bit too effusive for a transactional relationship, Sue thought. At one point, Sue’s member advocate suggested sending a Cofertility staffer on one of Sue’s medical appointments to take new photos for her donor profile, and Sue began to wonder how she was being marketed. What was wrong with the current shots?
Sue had her first egg retrieval on September 17, 2025. The yield was strong: The doctor retrieved 26 mature eggs, all of which became Cofertility merchandise, available for sale to intended parents. At her door, Sue received “a very, very, very cheap flower,” she recalls, and thought, “What the hell is this?” It was from Cofertility, with a note thanking Sue for her donation.
Post-egg-retrieval symptoms might be compared to a menstrual period cranked through an amplifier—Sue remembers the time as a fog of pain and bleeding, when she felt too sluggish to move around or mount an argument. She was still in the thick of her recovery when her member advocate gave her a call. When did you want to schedule your next retrieval? Sue was asked. This was for the batch of eggs that Sue would get to keep.
Sue’s contract said she had to do the second retrieval within a year of the first. She suggested six months out, maybe March, so she could have time to recover and focus on school. This seemed to make her member advocate “very upset,” Sue recalls. The company was hoping Sue would be ready to go before the end of the year—in November, perhaps? According to a promotional post by medical adviser and doctor Meera Shah on the Cofertility website, some donors might be ready to repeat the egg-retrieval process after one menstrual cycle. “In other cases,” Shah writes, “your fertility doctor may advise a longer waiting period … You’ll want to get input from your doctor and also listen to your body’s signals.”
Sue felt that November was too soon. Two other things bothered her. One was that when she tried to view her donor profile, she got stuck on a page that said “Oops! Something went wrong,” under a banner in Cofertility’s signature teal. The other was that Cofertility’s “attitude changed a lot,” Sue says, especially over the phone. The company whose warmth she’d once found stifling was now clipped, cold, all business. Ahead of a second cycle destined to yield no profit for them, Sue felt like she was no longer a priority.
Sue’s member advocate did not respond to a request for an interview. In an emailed statement, a Cofertility spokesperson says that “the care a donor receives for a cycle has nothing to do with whether the eggs are being donated or kept,” and while it’s true that subsequent cycles can move faster, “it’s due to familiarity, not pressure.”
Sue, wanting to succeed with the program, did as her member advocate suggested and scheduled her second retrieval for November 18. But she wouldn’t let her suspicions go. As she recovered from the first procedure, she hatched a plan to learn more about the company to which she’d just handed her genetic material. “If I say four retrievals,” Sue wondered, “what would their reaction be?” She did just that, asking to double her ovarian output. Cofertility would get the first and second batches; Sue would get the third and fourth. The company accepted.
“Ah,” Sue recalls with satisfaction, “they become warm again.”
Cofertility’s pitch might seem a bit less convincing if you understand how egg freezing—and, later, fertilization and conception—really works. With the company’s Fresh split model, “the egg donor is not going to be able to have the best likelihood of having a live birth from half a cycle,” says Eve Feinberg, a reproductive endocrinology specialist at Northwestern’s medical school.
Technically speaking, you only need one egg to have a baby. But for that one egg to one day become a person, everything has to go right. Human eggs are single cells, fragile and accustomed to spending their entire existence in a territory spanning a few inches. When you trigger their growth with a hormone regimen, you subvert the expectations of monthly single-cell deployment and prompt a whole batch of potentially dozens to get ready to drop. Some of them won’t mature all the way—and, with the current technology, immature eggs are about as reproductively useful as a grain of sand. Some won’t be genetically normal, which a doctor can’t tell until they try to fertilize them with sperm. Others might not freeze right.
It’s attrition—the egg-to-embryo-to-fetus-to-baby ratio is often described as an inverted pyramid—so when Cofertility donors give away half their frozen eggs, they don’t know if their best shot lies in the portion they kept. The fertility experts I spoke to emphasized that Cofertility has an obligation to explain to patients that the service would not offer the same benefit as one where, say, they paid in cash and got to keep all their eggs. “I don’t think they drove hard on how low the probability is, to be honest,” says Mona, who otherwise describes the company’s medical coordination as thorough, careful, and generous. “Maybe that would be something that they could have done a little bit better.”
None of the three donor-freezers I interviewed for this story—one of whom ended up being rejected from the program because of low AMH after her initial intake—said they received explicit counseling on how splitting cycles could reduce their chances when using their eggs in the future. Nor did three sets of intended parents I spoke to, all of whom spent thousands of dollars and walked away without a baby. When I put the same question to two more donor-freezers whose interviews Cofertility arranged, one said she was pretty sure that was made clear. The other said “no,” before a spokesperson cut in to add: “It was likely in your informed consent call with the Cofertility team.”
In a statement to WIRED, the company notes that because Cofertility donors are required to have higher ovarian reserves, they retrieve an average of 24 eggs, or 12 retained per Split cycle. “Research supports that 12 frozen eggs from an egg donor is a solid start towards a live birth, on average,” a spokesperson says. They add that the topics covered in the initial intake “have evolved over time” and can vary depending on a donor’s perceived familiarity with the process.
