Ozempic and similar weight loss drugs may raise the risk of kidney cancer, a major study suggests.
But the fat-melting shots lower the risk of over a dozen other cancers, meaning the benefits may still outweigh the risks.
The findings come as part of the world’s largest study of weight-loss drug users which looked at 86,000 obese or overweight patients tracked for up to ten years.
Overall, researchers found users had a 17 percent lower risk of being diagnosed with 16 cancers compared to people of similar weight who did not take the drugs.
This was particularly marked for endometrial cancers, where the risk was reduced by 15 percent, and ovarian cancers, where the risk was reduced by 47 percent.
Both of those cancers are strongly linked to obesity.
But kidney cancer was an outlier. Patients taking weight loss meds were a third more likely to be diagnosed.
Dr Hao Dai, a health data scientist at Indiana University who led the research, stressed that the study was observational and did not prove that weight loss drugs like Ozempic cause kidney cancer.
But he told the Daily Mail the results were ‘concerning’ and underlined the need for further research.
Real Housewives of New Jersey star Dolores Catania, pictured in 2018 and 2024, suffered nausea while taking weight-loss shots. One theory is that sickness and vomiting side effects may trigger repeated bouts of acute kidney injury, raising the risk of cancer
Brad Roberts had a hellish experience on Ozempic. He is in so much pain in his joints, muscles and stomach that he spends up to 18 hours a day in bed
Kidney cancer is often called a ‘silent’ cancer because it can grow without causing obvious symptoms in its early stages.
When symptoms do appear, doctors say it is often too late. The chances of survival plummet when the tumor has spread elsewhere in the body.
Symptoms may include blood in the urine, lower back pain, or a palpable mass.
In the new study, scientists recruited 43,000 patients who were on weight loss drugs, and matched them to 43,000 control patients that had the same characteristics but were not on the medications.
Data was drawn from the FloridaOne+ database, which stores data on the medical history of millions of patients in Florida.
Participants had an average age of 52 and nearly seven in 10 were female.
None had a cancer diagnosis at the start of the study.
Half were taking the drugs for type 2 diabetes and half took them to treat their obesity.
Over an average of three years, researchers recorded 1,900 cases of 16 different cancers in the group.
Of these, 891 were recorded among patients taking weight loss drugs, while 1,022 were recorded among people not taking the drugs.
For kidney cancer, however, there were 83 cases recorded among patients on GLP-1 drugs compared to 58 cases in the control group.
Researchers said they plan to keep tracking the patients for longer to confirm the data.
But their results are in line with other research on weight-loss drugs and kidney cancer.
A study published in July last year on 1.6million type 2 diabetics found that patients taking Ozempic-like drugs had a 54 percent higher risk of suffering from kidney cancer compared to diabetics taking the cheap diabetes drug metformin.
Another study published in May on 1.2million patients with type 2 diabetes also suggested a 45 percent higher risk of being diagnosed with kidney cancer among patients on the drug compared to those taking metformin.
Dr Neil Iyengar, an onoclogist at Memorial Sloan Kettering Cancer Center in New York who was not involved in the latest study, told the Daily Mail that he ‘didn’t fully buy’ the potential link with kidney cancers, highlighting that other research has shown GLP-1 drugs actually protect against kidney cancer.
‘The issue is that we’re still at a very early stage gathering GLP-1 data which will give us mixed result,’ he said.
‘We do need more data to address this potential kidney cancer issue, however.’
The latest study was presented at the American Clinical Society of Oncology’s annual conference in Chicago, Illinois, the largest cancer conference in the world.
Dr Dai is also cautious about over-interpreting the findings.
‘We need to do another observational study to confirm that these drugs increase the risk,’ he told this website.
‘But from my point of view, it might be that the drugs raise the risk of some types of kidney cancer. We don’t know, however, and need to do more research.’
A slide he shared during his presentation read, ‘Monitoring for kidney cancer: Observed trends toward increased kidney cancer risk emphasizes the necessity for ongoing surveillance and further investigation.’
One theory is that the drug’s common side effects, including severe nausea, vomiting, and dehydration, may trigger repeated bouts of acute kidney injury.
Over time, that stress could damage kidney tissue and increase the risk of mutations that lead to cancer.
Another area of concern is that the kidneys contain GLP-1 receptors. These are the same receptors Ozempic targets to regulate blood sugar and keep people full.
Some scientists wonder whether constantly stimulating these receptors could cause cells in the kidneys to grow out of control, though this remains speculative and has not been proven in humans.
Rapid weight loss and dramatic metabolic shifts caused by the drug might also play a role, potentially altering the body’s immune response or revealing preexisting kidney issues.
Kidney cancer is estimated to be the seventh most common cancer in the US, with about 80,000 cases diagnosed in the country every year.
In the UK there are almost 14,000 new diagnoses and 4,700 deaths annually from the disease.
Kidney cancer has a good survival rate if it is diagnosed at an early stage, with 75 percent of patients living five years or more.
But if the cancer is diagnosed when it has spread to other areas of the body, this drops to 18 percent.
The most common type of kidney cancer, renal cell carcinoma, accounts for about 90 percent of adult kidney cancers.
While age is a risk factor — most patients are diagnosed over 60 — there’s been a concerning uptick in cases among younger adults.
People born in 1990 are experiencing kidney cancer rates two to three times higher than those born in 1955.
Some researchers attribute this rise partly to improved imaging and earlier detection, but environmental factors, obesity, and high blood pressure may also play a role.
