My research helped invent Ozempic — then male scientists took all the credit

“I still remember clearly the excitement,” Mojsov says today in her office in New York, where she is research associate professor at the Rockefeller University. The hope was that Mojsov’s mixture would coax the rat’s pancreas into doing what diabetes prevented it from doing in the body: releasing insulin when blood sugar rose.

“Weir called to tell me that insulin levels were dramatically increased at very low concentrations [of the mixture]. That effect was not seen before.”

Mojsov thought that success might open the way to a powerful new treatment for diabetes. Four decades later it has turned out to be much more important than that.

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The mixture that she had conjured up — known as GLP-1 (glucagon-like peptide-1) — is now the secret sauce in weight-loss drugs such as Ozempic, Wegovy, Mounjaro and Zepbound. Together these drugs are changing the world one injectable jab at a time. In the UK about 1.6 million people are now taking them. Their manufacturers believe their popularity will eventually be double or triple that. They can help users shed almost a quarter of their body weight. They treat or prevent diseases such as type 2 diabetes, kidney disease and non-alcoholic fatty liver disease. Dozens of studies are under way to discover if they can also address everything from dementia and polycystic ovary syndrome to skin conditions such as psoriasis and chronic inflammation. In other trials, scientists are investigating whether these drugs might treat addictions such as smoking, alcohol and gambling — in lab rats, the medications have reduced cravings for cocaine.

Mojsov herself is now working full time, at 78, on how artificial intelligence can help figure out new uses for GLP-1 drugs.

All of this can be traced back to that day in a Boston laboratory in 1986. After watching the experiment Mojsov returned to her own much smaller lab at Massachusetts General Hospital — Mass General — where she worked, and began to write up her findings. Months earlier she had consulted her mentor, Bruce Merrifield. “I told him about my experiments,” she recalls. “He listened and then told me to go out and buy a stack of hardback notebooks and document everything carefully.”

Merrifield, a titan in his own field of chemistry who had just won a Nobel prize for developing a faster way to synthesise proteins, knew that in the scramble for scientific glory, the battles are not only fought in laboratories. Mojsov had no idea how valuable his advice would be.

The experiment that she had just been central to was meticulously written up, peer-reviewed and ultimately published by one of the top scientific journals in the world, with Mojsov as the first named author.

Even so, over the subsequent decades her involvement would be slowly wiped from the record. Three men — two of whom she worked with — would go on to win the most prestigious prizes in biomedical science for their work on GLP-1, while she was relegated to nothing more than a footnote in the story. Svetlana Mojsov would need to prove herself all over again.

In 1972 a 25-year-old graduate of Belgrade University stepped off a plane from Europe into the busy arrivals hall of JFK airport in New York City. Short and slim, with hair cut into a bob that framed piercing and inquisitive blue eyes, Mojsov was looking for a chance to leave her mark on science. As her taxi crossed the Queensboro Bridge, the imposing steel structure carrying multiple levels of cars over the East River into Manhattan, she was amazed by its scale. The dark grey concrete skyscrapers and the bleak, dirty streets that she found on the far bank impressed her less but faded from view once she reached the leafy campus of the Rockefeller University, a private graduate university for biomedical research on the Upper East Side.

Obesity was not yet on the radar of American doctors and nurses but she and her PhD classmates at Rockefeller learnt that the university’s hospital was conducting metabolic studies on severely overweight patients. “I thought that these people were an exception and not something we were going to see in the future,” she says now. Yet to Mojsov, who had grown up eating modest portions of Balkan staples such as spinach pie and goulash, the signs that Americans were already consuming vast amounts of unhealthy food were obvious.

“I remember seeing all the pastrami and the big cheeseburgers,” she recalls. “I had never seen a steak before, let alone the giant steaks with potatoes. It was huge. The meals were huge.”

Although it was widely believed at the time that obesity was solely due to a lack of willpower, some researchers were beginning to uncover more nuanced causes of severe weight gain.

A scientist named Doug Coleman had sutured two mice together, one obese and one thin, so they could share the same blood supply. After a few weeks the overweight mouse started losing weight, which led Coleman to suggest in 1973 that there was “a satiety factor” in the blood of the thin mouse that the obese one couldn’t make. “It was that experiment that showed there must be some factor that causes obesity,” Mojsov says.

In 1983 she moved to Boston with her husband, Michel, an immunologist who had a residency at Mass General. The huge complex, which includes a world-renowned diabetes centre, is the largest teaching hospital of Harvard Medical School and was intensely hierarchical. Harvard-trained physicians ruled. PhDs such as Mojsov were near the bottom. She was hired to create proteins for the other scientists in the building but quickly secured a senior research position that gave her some funding and therefore independence. “It was clear from the very beginning I would have my own project,” she says.

She soon heard of Joel Habener, a balding and bespectacled endocrinologist, who worked two floors down from her. He was already a star. One year before, Habener and his team had identified a long chain of amino acids in fish that resembled glucagon. This proved to be a hormone involved in regulating blood sugar: GLP-1.

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Mojsov became fascinated by the body’s different ways of working with blood sugar and spent months chemically synthesising GLP-1 and then tracking down its origins using antibodies. Word of her activities reached Habener’s lab. But rather than venture down to a relatively unknown chemist’s domain, he sent Daniel Drucker, a Canadian postdoctoral researcher working in his lab.

Mojsov was wary of Drucker. On the surface he seemed pleasant — a young, energetic and handsome medic with soft brown eyes that creased at the edges when his smile would break out mid-speech. But as she listened to his proposal to join forces, it seemed transactional. “I couldn’t put my finger on it,” she says. “He looked entitled. But I was collaborative and I was discovering this new peptide and I was interested in what he was doing.”

Habener himself became friendlier. He would drop into Mojsov’s lab every few weeks seeking some of the GLP-1 she had synthesised for his own experiments. The two men, along with other members of Habener’s lab, began using her ingredients and techniques to track different forms of GLP-1 in rat tissue.

In September 1986 Habener and Mojsov published a joint paper. It detailed the discovery of GLP-1 in the gut, and Mojsov identified its active form. She is listed as first author on that paper and Habener is last, as is typical for the senior author on a paper.

“This was really a foundational paper,” she says. “It has it all. It is complete.”

Endocrinologists agree with her assessment and consider this paper to be a watershed moment in the discovery of GLP-1 drugs. The timing was critical. It was published in the same month Jens Juul Holst from the University of Copenhagen presented the same findings at a conference in Rome. The transatlantic rivalry intensified as the two teams sought a much larger prize: to be the first to show that GLP-1 could treat diabetes.

Within a few months Mojsov teamed up with Weir for the landmark experiment with the rat pancreas that showed that GLP-1 controlled insulin levels. It depended on their shared expertise and that of Habener. Without his early research Mojsov would not have known about GLP-1, but without her subsequent mixing of the ingredients the breakthrough would have never been possible.

“That was a very critical experiment,” Mojsov says. “It shows how pure I got the GLP-1 to be.”

The paper that detailed their findings was published in 1987 in The Journal of Clinical Investigation. Mojsov was listed as the first author, Weir was second and Habener last.

Meanwhile, in the same building, Drucker, the smooth Canadian, and another postdoctoral researcher called Jacques Philippe were working on different experiments but hoping for the same outcome. Habener had instructed Drucker to try to figure out how GLP-1 works. Mojsov didn’t realise it at the time, but this project was in competition with her own research.

Like Mojsov, the duo found that one version of GLP-1 stimulates more insulin than a longer version of the peptides. Drucker’s paper was published in May 1987, three months after Mojsov and Weir’s. Mojsov was happy to help Drucker because they both worked for Mass General. Up until that point it all seemed relatively collegiate.

On a sunny day in May 1993, at the first international symposium on GLP-1, Mojsov ran into Habener walking on the lawn of the Vilvorde Conference Centre just north of Copenhagen. By then she was back at Rockefeller but she still wondered why Mass General had never applied for patent protection of GLP-1. After exchanging greetings, she asked Habener about patents. He just turned around and walked away. It was a bizarre, awkward interaction. Although the two scientists had never been friends, they had collaborated closely at a very important time in both of their careers.

Eventually Mojsov put the pieces of the puzzle together. In 1996 a colleague on a separate project mentioned that Mass General had been granted patents for the discovery of GLP-1 in 1992, the year before she bumped into Habener. He was listed as its sole inventor. Without telling her, Habener had then applied for a separate patent using some of Mojsov’s research in 1993, a little over six months after he had bumped into her in Copenhagen.

“When I found out I was shocked,” she says. “I hadn’t looked for the patents but I had always thought I would be on them.”

She found a patent lawyer who looked through her notebooks and told her that he expected Mass General to roll over relatively easily and admit that a mistake had been made. A letter was fired off to the hospital. There was no response for a year, so Mojsov’s lawyer sent another letter. “I was really surprised and my lawyers were really surprised why Mass General ignored us,” Mojsov says. “It just went on and on.” Then Mass General hired an elite intellectual property law firm from Washington. They asked to interview Mojsov about her role in the GLP-1 discovery.

Much was at stake. The patent holder would receive a significant percentage of royalties from any GLP-1 drugs, not to mention the fame associated with inventing a novel and powerful drug. At this stage the Danish pharmaceutical giant Novo Nordisk had already bought the licensing rights for GLP-1 in 1992 from Habener. The company was actively seeking to create the world’s first diabetes drug, building on Mojsov’s discovery.

“I was advised to be very careful,” Mojsov says. “I needed to prove my contribution but not discredit Habener, or the patents could be in jeopardy — and that could have undermined Novo Nordisk’s efforts to make a drug.”

The legal exchanges grew heated between Mojsov and Mass General’s lawyers. “I don’t remember crying because there was so much anger,” she says. “I had to calm myself down.”

Then, out of the blue in 2006, the hospital agreed to amend five patents to include Mojsov as a co-inventor. For this Mojsov had to concede a lot of ground. “At first I insisted that we had to have half and half,” Mojsov says. “But my lawyer told me I had to compromise.” In the end she was awarded a third of drug royalties. Habener received the rest.

It wasn’t much money anyway. By the time Novo Nordisk’s first GLP-1 drug was approved by the US Food and Drug Administration (FDA) in 2010, there was only a year left on the patent. But Mojsov had been vindicated.

She thought back to the advice her mentor, Bruce Merrifield, gave her about the notebooks. “He told me to keep the dates. It was very helpful. That’s how I finally got the patent.”

The fight was far from over, though.

Habener, Drucker and Holst all agree that Mojsov made an important contribution to the GLP-1 discovery. Habener says he told Mass General that she also deserved to be on the patents. Still, none of these men has gone to great lengths to ensure that the scientific community knows the extent of her involvement.

In 2021 the three men shared the Canada Gairdner International award, often seen as a precursor to a Nobel prize, for their work on GLP-1. The Gairdner was the third award in four years that they won for research that began in the 1980s. A week after the ceremony, Mojsov read a follow-up article about their work in Cell, a top academic journal. It was littered with inaccuracies. It incorrectly described Habener as the sole inventor of GLP-1. It wrongly described her as a junior member of his laboratory. There was no mention of Mojsov being a co-inventor on multiple patents.

“I felt like this was becoming a pattern,” she says now. “One of the ways to diminish my work was to say I was a postdoctorate of Joel Habener because, in the Harvard Medical School hierarchy, medical doctors [such as Habener] are always above postdocs who have a PHD and are always at the lower level. I was aware of it but I didn’t pay attention.”

So on a crisp sheet of paper Mojsov hand-wrote a letter of complaint to the editor of Cell, correcting the errors in the article one by one. She received an apology and the article was amended. It was a small but vital victory.

As the Gairdner award indicated, the impact of GLP-1 puts its discoverers on course to win a Nobel prize in physiology or medicine. But the prize rules mean that the accolade can be split only three ways at most. So unless Mojsov can establish her claim, she will be left out of a once-in-a-lifetime opportunity to earn the highest accolade in her field. The correction in Cell marked the first moment that the wider scientific community embraced the true significance of her work. It also led to further supportive coverage in the science press.

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Finally, in September 2024, Mojsov received heavyweight public recognition for her role in the discovery of GLP-1. Along with Habener and Lotte Bjerre Knudsen, a medicinal chemist at Novo Nordisk, she won the Lasker-DeBakey Clinical Medical Research award, America’s top prize in biomedical research. The honour suggests that if and when the Nobel committee recognises the scientists who blazed a trial towards the Ozempic age, there is a good chance that Svetlana Mojsov will be one of the three on the podium.

Habener called to congratulate her. The “short and cordial conversation” was the first time that they had spoken in more than 30 years.

The Lasker-DeBakey ceremony, a modest lunch of chicken and salad, was held at New York’s Pierre Hotel. Mojsov was accompanied by her husband, son and daughter. She stood up and made a brief speech, explaining what an honour it was to receive the award, thanking her mentor, Bruce Merrifield, and emphasising the importance of collaboration in science. Habener was sitting three seats to her right. She didn’t mention him once.

When she sat down, her son leant over and whispered in her ear, “You did it, Mum.”

Off the Scales: The Inside Story of Ozempic and the Race to Cure Obesity by Aimee Donnellan (Fourth Estate £20). To order a copy go to timesbookshop.co.uk. Free UK standard P&P on orders over £25. Special discount available for Times+ members

Science’s overlooked heroines

Named after the American suffragist Matilda Joslyn Gage, the “Matilda effect” is the phenomenon of female scientists being sidelined in favour of their male peers, writes Julia Chadwick.

Jean Purdy

A clinical embryologist whose work contributed to the birth of the first “test tube baby” in 1978. Her collaborator, who tried in vain to advocate for Purdy, was given the Nobel prize in physiology or medicine in 2010 and was knighted a year later.

Jocelyn Bell Burnell

While studying for her doctorate at Cambridge University in 1967, Bell discovered pulsars — rapidly rotating neutron stars. The find helped her supervisor win a Nobel prize in physics seven years later.

Chien-Shiung Wu

A key member of the Manhattan Project, Wu disproved the “law of parity conservation” in 1956. The “Wu experiment” validated the theories of two scientists who went on to win a Nobel prize in physics the following year.

Lise Meitner

An Austrian physicist who fled to Sweden to escape Hitler, Meitner became part of the team who discovered nuclear fission in 1938. Six years later her former colleague won the Nobel prize in chemistry.

Candace Pert

Despite being told to abandon the work by her supervisor, Pert discovered the brain’s opiate receptor in 1973. This laid the groundwork for the discovery of endorphins by two British researchers two years later. They won the Lasker award — shared with Pert’s supervisor.

Alice Ball

The first woman to become a chemistry instructor at the College of Hawaii, Ball devised an effective treatment for leprosy at 23. She died shortly after in 1916 from suspected chlorine poisoning in a lab. The college president published her research under his own name.