A new risk: Kidney Cancer
New study suggests link between GLP1 Receptor Agonists (Ozempic, Mounjaro, etc) and kidney cancer.
While it's great to hear of new benefits of using GLP1 Receptor Agonists every few days or weeks, it's equally (if not more) important to hear about new negative side effects (with or without evidence).
Check out our quick explainer
We've reported on the negative side effects on before (and try to do so regularly):
GLP1.Guide Staff
Recently there have been reports of a possible new negative side effect of taking GLP1s – kidney cancer.
As is often the case, financial markets are first to start sharing this widely:
Vaishali Prayag
What does the research say?
The study highlighting the risk is a analysis published in the Journal of Clinical Oncology:
As this was not a live experiment or longitudinal study, the data used for this paper comes from existing medical records:
This retrospective cohort study followed a target trial emulation design using 2014–2024 OneFlorida+ electronic health records (EHR) data.
The amount of data in the study was large for a study but not large for an analysis – 43,317 patients on GLP1s were compared with 43,315 patients NOT on GLP1s.
The results are quite interesting so they're posted below, with emphasis added:
Results: After matching, 43,317 GLP-1RA users were compared with 43,315 non-users.
The incidence rates of the 16 cancers were 20.5 versus 23.6 per 1,000 person-years, respectively, indicating a significantly lower overall cancer risk among GLP-1RA users (HR, 0.83 [95% CI, 0.76–0.91]) compared to non-users.
In particular, GLP-1RA use was associated with a reduced risk of endometrial cancer (HR, 0.75 [95% CI, 0.57–0.99]), ovarian cancer (HR, 0.53 [95% CI, 0.29–0.96]), meningioma (HR, 0.69 [95% CI, 0.48–0.97]), and esophageal adenocarcinoma (HR, 0.34 [95% CI, 0.12–0.94]).
However, GLP-1RA users showed a trend toward an increased risk of kidney cancer (HR, 1.38 [95% CI, 0.99–1.93]), particularly among the younger adults (≤65 years) and overweight patients (BMI 27–29.9).
While we're quite familiar with the earlier results (GLP1s reducing the risk of various cancers), the trend towards increased risk of kidney cancer is alarming.
More importantly, younger people and overweight patients seem to be most at risk, which likely applies to many people who take GLP1s for weight management.
This isn't the first cancer to be associated with GLP1s
GLP1s were originally theorized to be linked to thyroid cancer:
GLP1.Guide Staff
This link has faded over time, as evidence has not materialized, but it's important to keep in mind that there are researchers actively finding and investigating probable links.
Not every possible new negative side effect pans out as influential or significant over time, but every one is worth investigating and keeping track of.
The link to Kidney Cancer fits
The most negative side effect (that even lead to one of the only publicized deaths attributable to GLP1s) are gallstones and pancreatitis:
GLP1.Guide Staff
Gastrointestinal issues are the main negative side effect of using GLP1s, and issues with the pancreas, galbladder and kidney being very active participants in the gastrointestinal system.
Kidneys being at greater risk are in line with the current known/emphasized negative side effects for GLP1 Receptor Agonists. The link is not conclusive, but it's not completely unreasonable on it's face.
Weight loss (helped by GLP1s) is still hugely beneficial in reducing cancer risk
It's important to note that the paper was quite clear about the reduction of cancer risks of sixteen different cancers:
The incidence rates of the 16 cancers were 20.5 versus 23.6 per 1,000 person-years, respectively, indicating a significantly lower overall cancer risk among GLP-1RA users (HR, 0.83 [95% CI, 0.76–0.91]) compared to non-users.
This is a significant benefit and is important to consider – the number of health problems that are linked with obesity is large, and cancer is one of them (amongst many others).
Obesity itself can often make cancer worse – most news sources today are still reporting on the benefits of GLP1s for weight loss and cancer risk reduction:
Liz Highleyman
This article lists out some of the really impressive risk reductions that GLP1s provide, with links to papers backing the assertions:
Drugs in this class have been shown to lower the risk of cardiovascular disease and kidney disease and improve fatty liver disease, sleep apnea and arthritis pain. What’s more, ongoing research suggests additional benefits, including better cognitive function and reduced alcohol consumption.
This article isn't wrong – in fact most of the research that has had conclusive results points in the direction of cancer risk reduction.
Both of the following are true.
At this point both the following statements are true:
- GLP1 Receptor Agonists like Ozempic and Mounjaro likely reduce cancer risk for cancers which are worsened by obesity
- GLP1 Receptor Agonists like Ozempic and Mounjaro may increase the risk of kidney cancer
Kidney cancer has not shown up yet in anecdata (which will likely be very difficult to find amongst so many lifestyle factors), but this risk is relatively new and is worth looking out for.
The bottom line
With this new risk emerging the emphasis on a balance of risks and benefits for GLP1s will remain in focus: for many the reduction in mortality from many causes (diabetes, heart disease, inflammation-related diseases, cancer) will likely outweigh an increased risk of kidney cancer.
As always, any regimen of medication like GLP1s should always be started with consultation from your personal care physical or other qualified medical professional– if you're worried about kidney cancer, the right person to take these concerns to is a doctor or oncologist who can help and facilitate testing or provide evidence-based care.
