The Role of Weight Loss Medications and Cancer Risk: Separating Fact from Fiction

by | Nov 23, 2023

Overweight and obesity rates continue to climb and the associated health risks are becoming increasingly apparent. It is critical to find effective weight loss solutions now more than ever. Given how difficult sustained weight loss is with the typical “diet and exercise” approach, GLP-1 agents, such as Semaglutide and Tirzepatide, present an exciting option on the market today. Concerns have arisen, however, about the safety of these medications, particularly regarding a potential link to cancer. In this blog post, we will explore the relationship between GLP-1 agonists, weight loss, and cancer risk, shedding light on the facts and dispelling misconceptions.

The Obesity-Cancer Connection

Before delving into the specifics of GLP-1 agonists, it’s essential to understand the strong link between obesity and cancer. Numerous studies have demonstrated a powerful association exists between excess body weight and an increased risk of several types of cancer, including breast, pancreatic, liver, uterine, ovarian, kidney, and colon cancer, just to name a few. The mechanisms underlying this connection are complex, but they often involve chronic inflammation, insulin resistance, and alterations in hormone levels. However, regardless of mechanisms, research has shown that a whopping 40% of U.S. cancer cases are related to obesity.

GLP-1 Agonists: Weight Loss Champions

GLP-1 agonists like Semaglutide and Tirzepatide belong to a class of medications initially developed for the treatment of type 2 diabetes. However, they have garnered significant attention for their remarkable and unparalleled weight loss effects shown in clinical trials over the past decade with many patients losing 15-20% of their body weight in just a few years of therapy, and generally with few and manageable side effects.

The Animal Data Concerns

A common concerns raised by patients regarding GLP-1 agonists surrounds cancer risk. It’s important to note that this concern is based almost entirely on animal studies. In some animal experiments, there were indications that these medications might promote the growth of certain types of tumors of glands, particularly the thyroid. However, it’s essential to recognize that animal research does not always translate directly to human outcomes.

Human clinical trials consisting of thousands of patients to date plus extensive real-world experience have not shown a similarly concerning increases in cancer risk associated with the use of GLP-1 agonists for weight loss.

The Bigger Picture: Weight Loss as a Cancer Risk Reducer

While cancer concerns surrounding GLP-1 agonists stem from animal data, the broader picture highlights the potential benefits of these medications for cancer protection. Losing weight is undoubtedly one of the most effective ways to reduce the risk of cancer associated with obesity. For individuals struggling with obesity, shedding excess pounds can be incredibly challenging through diet and exercise alone. GLP-1 agonists offer a viable solution to help patients achieve and maintain a healthier weight. Therefore, that is why it is likely that, in time, cohort studies following patients taking GLP-1 agonists over many years and decades could very well show that patients on these medications indeed have lower rates of many types of cancer.

The relationship between GLP-1 agonists, weight loss, and cancer risk is a complex and evolving topic. While concerns based on animal data have been raised, the evidence to date from human studies suggests that these medications can be valuable tools in managing obesity and could therefore be expected to reduce the risk of cancer associated with excess body weight.

(As with any medical treatment, it’s essential to consult with healthcare professionals who can provide personalized guidance based on an individual’s unique health profile and needs. The goal is to strike a balance between addressing obesity, mitigating cancer risk, and ensuring overall well-being.)


Joshua Russell, MD
Chief Medical Officer, Founder
Flow Wellness |

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