Can Mounjaro really help fight cancer? The surprising new science (plus why your GLP-1 really isn’t just about the scales)

Anna-Louise Dearden | Last update: 19th July 2025

The SlimrChat question

This new study shows that Mounjaro might shrink tumours as well as waistlines – but why would weight loss help with something like breast cancer?

Obesity and biology

“There’s growing evidence that excess weight isn’t just a cosmetic concern, it’s a significant biological driver of certain cancers, particularly postmenopausal breast cancer. As reported by Breast Cancer UK, being overweight or obese increases the risk of breast cancer by up to 30% in postmenopausal women.”

Post menopause and inflammation

“This is largely due to how fat tissue behaves in the body. After menopause, fat becomes the primary source of the hormone oestrogen, and elevated oestrogen levels are known to increase the risk of hormone-sensitive breast cancers. Fat cells also release leptin; a hormone linked to tumour growth. In addition, excess weight contributes to chronic inflammation and insulin resistance both of which can create a cellular environment that supports cancer development.”

Potential to reduce tumour growth

“These early findings are fascinating to watch. While the data are still preliminary, they show the potential that GLP-1 medications like Mounjaro may not only reduce body and fat mass but also help disrupt the hormonal and inflammatory pathways that contribute to tumour growth. It’s an exciting area of research to watch.”

The SlimrChat question

And for people living with obesity, could weight loss meds like Mounjaro really protect their health in ways beyond just the scales?

Multiple benefits

“For people living with obesity, the benefits of GLP-1 medications like Mounjaro go far beyond just weight loss. Obesity is a complex health condition that increases the risk of serious chronic diseases, including type 2 diabetes, heart disease, and fatty liver disease.  By reducing excess fat, particularly visceral fat, these medications can help improve insulin sensitivity, lower inflammation, and have shown to reduce blood pressure and cholesterol levels.”

A better quality of life

“What we’re seeing is a shift in how we view obesity treatment. It’s no longer just about the number on the scale; it’s about reducing the biological risks that come with carrying excess weight. We’re also now seeing a wave of studies highlighting the broader potential health benefits of GLP-1 medications on conditions like sleep apnoea and PCOS. It’s a powerful reminder that these medications are about treating the underlying drivers of poor health and giving people a better quality of life.”

So…what should you do right now?

As always at SlimrChat, we’re not saying GLP-1s are a magic bullet, especially for cancer prevention. But, if you’re already on them, here’s how to make the most of your journey.

Rachael’s Top Tips for GLP-1 Success

• Track more than weight. Notice changes in blood pressure, cholesterol, energy. These wins matter.
• Take it slow. Work with your provider on gradual dose increases to avoid nasty side effects.
• Prioritise protein and hydration. Tiny appetite? Make every bite count with protein-rich meals and plenty of water.
• Keep moving. Resistance training preserves muscle and bone – crucial when weight is dropping.
• Find your tribe. Whether it’s an app, a care team, or a community like SlimrChat, support makes it easier to stay on track.

SlimrChat takeaway:
This is early science, but it’s a huge reminder that obesity is a major health risk. 

GLP-1s like Mounjaro are helping to tackle that risk in ways we’re only beginning to understand. 

For now, keep doing what you’re doing: protein, movement, hydration, and community support. 

The scale is just one part of the story – it’s an improvement in your overall health and lifestyle we’re looking at.

Want to read the full study? Science Daily article
More on breast cancer risk: Breast Cancer UK