20.10.2025

Some people with obesity need long-term help when lifestyle changes don't work. The idea of a "skinny jab" sounds attractive: few injections, visible results, no restrictions. Behind the tempting image of the weight loss injection lies a complex therapy whose applications are now also of interest to sports medicine. MEDICA 2025 will address this topic.

In brief: drug-based weight loss

The "skinny jab" is not a miracle cure for weight loss, but it can help people who are severely overweight/obese to change their lifestyle.
Beyond weight loss, there are also numerous positive effects on overall health.
In sports where weight is an important factor, the drugs have the potential for abuse, which poses ethical and regulatory challenges.

"Many [people] struggle with obesity, which leads to joint pain, shortness of breath, or other conditions that prevent them from participating in sports and leading an active life. These drugs can be the decisive impetus to break this vicious cycle," says Dr. Tim Hollstein, University Medical Center Schleswig-Holstein in Kiel, Germany. He will address this topic at the MEDICA MEDICINE + SPORTS CONFERENCE.

Medications for high weight are not a "miracle cure," Hollstein continues, but "for many people, they make it possible to start or return to an active life in the first place and allow them to rediscover the joy of exercise."

How "skinny jabs" work

Several injection pens with protective caps removed, placed side by side, with needles visible – skinny jabs; Copyright: towfiqu98

Weight loss drugs ("skinny jabs") promise a simple treatment for obesity and overweight. However, the therapy behind them is actually more complicated, and the drugs should not be viewed merely as lifestyle injections.

Medication often colloquially referred to as "skinny jabs" belongs to groups such as GLP-1 receptor agonists or incretin mimetics. Such a drug mimics the effect of the body's own hormone GLP-1. The drug reduces the feeling of hunger, increases the feeling of satiety, and delays gastric emptying.

Weight loss drugs are known under various brand names (e.g., Wegovy, Ozempic, Saxenda, Zepbound, Mounjaro), which refer to different active ingredients (e.g., semaglutide, liraglutide, tirzepatide).

Previous weight loss drugs were either ineffective or unsafe, so they had to be taken off the market. "The new classes of drugs now offer us highly effective tools for the first time. Their relevance to sports medicine is enormous," says Hollstein.

The term "skinny jab" indirectly signals a lifestyle application for these drugs. Hollstein, on the other hand, sees it as "a paradigm shift in the treatment of the widespread disease of obesity." Beyond weight loss, he explains, there have been "impressive positive effects on a whole range of comorbidities such as cardiovascular disease, sleep apnea, fatty liver, and kidney disease. There are even initial indications of a reduction in the risk of dementia."

Lecture: Preserving muscle while leveraging next-gen weight loss therapies

Prof. Tim Hollstein at MEDICA 2025

Smiling man with short blond hair and dark jacket – Prof. Tim Hollstein; Copyright: private

PD Dr. Tim Hollstein, Senior Physician for Internal Medicine, Endocrinology, and Diabetology, University Medical Center Schleswig-Holstein (Kiel)

In his keynote speech, Prof. Hollstein will give a comprehensive overview of the current status and future developments of weight loss drugs. One focus will be on the mechanisms of action of the latest classes of substances and the study results already available – the combination with novel muscle-building drugs will also be a topic. Specifically, he will discuss the effects on body composition, i.e., the ratio of fat to muscle mass, which is of central importance for athletes. Potential risks and side effects will also be highlighted. In addition, he will discuss what an interdisciplinary approach combining medication and targeted training, especially strength training, might look like in order to achieve the best possible and most sustainable results.

To the lecture

All details and tickets to the MEDICA MEDICINE + SPORTS CONFERENCE

When is it appropriate to lose weight with medication?

The use of new drugs for cosmetic weight loss is highly controversial, as many people do not need to lose weight. However, the message is often conveyed online that even people of normal weight can and should use medication, even though other measures, such as lifestyle changes, diet, and exercise, would also help them.

However, this use has not been sufficiently researched and may therefore also carry risks. Another major problem with online sales is counterfeit drugs, the use of which is potentially dangerous.

In the field of sports, Hollstein also sees the risk of abuse, "for example, for rapid weight loss in sports with weight classes. This is an important ethical and regulatory challenge for associations and anti-doping agencies." However, such use must be clearly distinguished from the positive effects that the drugs have on people who are severely overweight or obese.