People on Ozempic may have fewer heart attacks, strokes and addictions – but more nausea, vomiting and stomach pain

Ozempic and Wegovy are increasingly available in Australia and worldwide to treat type 2 diabetes and obesity.

The dramatic effects of these drugs, known as GLP-1s, on weight loss have sparked huge public interest in this new treatment option.

However, the risks and benefits are still being actively studied.

In a new study in Nature Medicine, researchers from the United States reviewed health data from about 2.4 million people who have type 2 diabetes, including around 216,000 people who used a GLP-1 drug, between 2017 and 2023.

The researchers compared a range of health outcomes when GLP-1s were added to a person’s treatment plan, versus managing their diabetes in other ways, often using glucose-lowering medications.

Overall, they found people who used GLP-1s were less likely to experience 42 health conditions or adverse health events – but more likely to face 19 others.

What conditions were less common?

Cardiometabolic conditions

GLP-1 use was associated with fewer serious cardiovascular and coagulation disorders. This includes deep vein thrombosis, pulmonary embolism, stroke, cardiac arrest, heart failure and myocardial infarction.

Neurological and psychiatric conditions

GLP-1 use was associated with fewer reported substance use disorders or addictions, psychotic disorders and seizures.

Infectious conditions

GLP-1 use was associated with fewer bacterial infections and pneumonia.

What conditions were more common?

Gastrointestinal conditions

Consistent with prior studies, GLP-1 use was associated with gastrointestinal conditions such as nausea, vomiting, gastritis, diverticulitis and abdominal pain.

Other adverse effects

Increased risks were seen for conditions such as low blood pressure, syncope (fainting) and arthritis.

How robust is this study?

The study used a large and reputable dataset from the US Department of Veterans Affairs. It’s an observational study, meaning the researchers tracked health outcomes over time without changing anyone’s treatment plan.

A strength of the study is it captures data from more than 2.4 million people across more than six years. This is much longer than what is typically feasible in an intervention study.

Observational studies like this are also thought to be more reflective of the “real world”, because participants aren’t asked to follow instructions to change their behaviour in unnatural or forced ways, as they are in intervention studies.

However, this study cannot say for sure that GLP-1 use was the cause of the change in risk of different health outcomes. Such conclusions can only be confidently made from tightly controlled intervention studies, where researchers actively change or control the treatment or behaviour.

The authors note the data used in this study comes from predominantly older, white men so the findings may not apply to other groups.

Also, the large number of participants means that even very small effects can be detected, but they might not actually make a real difference in overall population health.

Other possible reasons for these links

Beyond the effect of GLP-1 in the body, other factors may explain some of the findings in this study. For example, it’s possible that:

• people who used GLP-1 could be more informed about treatment options and more motivated to manage their own health

• people who used GLP-1 may have received it because their health-care team were motivated to offer the latest treatment options, which could lead to better care in other areas that impact the risk of various health outcomes

• people who used GLP-1 may have been able to do so because they lived in metropolitan centres and could afford the medication, as well as other health-promoting services and products, such as gyms, mental health care, or healthy food delivery services.

Did the authors have any conflicts of interest?

Two of the study’s authors declared they were “uncompensated consultants” for Pfizer, a global pharmaceutical company known for developing a wide range of medicines and vaccines. While Pfizer does not currently make readily available GLP-1s such as Ozempic or Wegovy, they are attempting to develop their own GLP-1s, so may benefit from greater demand for these drugs.

This research was funded by the US Department of Veterans Affairs, a government agency that provides a wide range of services to military veterans.

No other competing interests were reported.

Diabetes vs weight-loss treatments

Overall, this study shows people with type 2 diabetes using GLP-1 medication generally have more positive health outcomes than negative health outcomes.

However, the study didn’t include people without type 2 diabetes. More research is needed to understand the effects of these medications in people without diabetes who are using them for other reasons, including weight loss.

While the findings highlight the therapeutic benefits of GLP-1 medications, they also raise important questions about how to manage the potential risks for those who choose to use this medication.

The findings of this study can help many people, including:

• policymakers looking at ways to make GLP-1 medications more widely available for people with various health conditions

• health professionals who have regular discussions with patients considering GLP-1 use

• individuals considering whether a GLP-1 medication is right for them.