Weight loss injections… what are the downsides?

Weight loss injections have taken the world by storm. Everyone is talking about them. Originally designed as a diabetes medication to lower blood glucose levels, in people with type 2 diabetes, GLP-1 agonists also reduce your appetite, which means they can help people without diabetes lose weight too.

BUT… what do we really know about these drugs and their affect on our bodies?

Lets consider the evidence from a recent study this year. A large observational study of over 200, 000 people published in the world renowned Nature Medicine journal, looked at the impact of taking GLP-1 agonists on over 170 different diseases using health information from over 2.4 million people with type 2 diabetes across the USA.

They compared around 215,000 people with diabetes prescribed weekly injections of GLP-1 agonists to just over 1.2 million people who continued to receive their usual non-GLP-1 medicines to reduce blood sugar. After just over 3.5 years, people taking GLP-1 agonists had a lower risk of developing over 40 different diseases than those given their usual medicines.

They found that GLP-1 agonists were associated with a reduced risk of substance use and psychotic disorders, seizures, neurocognitive disorders (including Alzheimer’s disease and dementia), coagulation disorders, cardiometabolic disorders, infectious illnesses and several respiratory conditions. Conversely, there was an increased risk of gastrointestinal disorders, individuals are thought to be nearly 2.5 times more likely to develop drug-induced acute pancreatitis, other side effects included a 30 per cent higher risk of nausea or vomiting, 11 per cent higher risk of arthritis and a 6 per cent higher risk of low blood pressure.

My advice….

If you’re thinking about starting weight-loss injections, first discuss your decision with your GP for tailored advice on whether they are right for you. Making changes to your lifestyle such as eating a healthy and balanced diet and taking regular exercise, is an evidence-based, safe and sustainable approach.

If you are struggling, please contact me for support.

Reference: Xie, Y., Choi, T. & Al-Aly, Z. Mapping the effectiveness and risks of GLP-1 receptor agonists. Nat Med 31, 951–962 (2025). https://doi.org/10.1038/s41591-024-03412-w