If you want to lose weight, you can do so with medication. But getting rid of them and staying slim is hardly possible. Studies show that the drugs also have an effect on the brain. Is a new addiction emerging?
Munich, Düsseldorf. “Wasted money,” says Manuela Badstübner. Not the one for the weight loss injection, but the one for the tennis lesson: It's a hot Thursday, Badstübner is on the tennis court, but she's having circulatory problems. Like always when she stuck the weight loss injection into her stomach like the day before and then wants to do some exercise in high temperatures.
She actually wanted to stop taking the injection for a long time. She was firmly convinced of this last autumn when Handelsblatt visited her. Not just because of the side effects, but also because she had almost reached her weight goal: 67 kilograms, that's how much she weighed seven years ago when she met her husband.
But instead the 55-year-old continues to inject. And now, because the weight loss pills have recently become available in Germany as pills, I want to switch to tablets. Although they have the same side effects, they are more pleasant to take and do not require refrigeration. Why doesn't Badstübner want to stop? Or can't she stop? Is a new type of psychological dependency emerging here?
The benefits of weight loss products are changing
More and more people are turning to weight loss aids. In the USA, around one in eight adults now takes it, as a survey by the American research institute Gallup from June shows. In Germany there is no official registration of users. However, market researchers estimate that more than four million people in this country use the medication - and the trend is rising.
The weight loss products have quickly become a billion-dollar market. The global market for GLP-1 drugs is expected to grow from $13 billion in 2020 to $135 billion in 2030, more than tenfold.
At the same time, perceptions in society are changing. US studies show that a growing proportion are not taking the drugs for the purposes for which they are clinically approved. These include people who are not overweight and use the medication to extend their lifespan, before a wedding or a summer vacation - or simply because it makes them feel better. Despite the prescription requirement, this is made possible primarily via telemedicine platforms on which doctors often issue prescriptions without a detailed examination.
This also creates the trend towards so-called microdosing - i.e. taking significantly smaller amounts than clinically intended. A possible opportunity that the manufacturers have long recognized: Novo Nordisk has been conducting clinical studies since August in which the company is investigating lower dosages in patients.
Mike Doustdar, head of Novo Nordisk, even announced in June that the drugs would also be positioned in the areas of longevity and aesthetics in the future. The company has already presented data that the active ingredient semaglutide could measurably reduce the biological age of the heart and kidneys.
This raises a key question for manufacturers, patients and researchers: What do the active ingredients do in the brain beyond weight loss? And can they really become addictive?
The weight loss injection and your own will
Behind the weight loss injections and pills there is an active ingredient that mimics the body's own GLP-1 - the hormone that is released after eating, stimulates insulin production and promotes the feeling of satiety. Originally developed as a diabetes medication, the active ingredient soon proved to be surprisingly effective in losing weight.
On June 1, 2025, Manuela Badstübner stuck the wafer-thin needle into her stomach for the first time. At that time she weighed 94.4 kilograms, today it is 68 kilograms. Because of the weight loss, she says she has more wrinkles on her face. But perhaps something else is more important: “My friends say: You’ve halved yourself.”
Badstübner, who heads sales and finance at Koller, an Austrian company that makes components for hot tub systems, injects herself with Mounjaro, Eli Lilly's shot. She is currently taking the dose of 7.5 milligrams, by no means the highest.
She already feels much better. The injection gave her a completely new self-confidence, a “mental transformation”. For her, this step was the “key to better health and a new quality of life”. It was as if she had “shed a heavy emotional burden” along with the pounds. What is particularly fascinating for her is the “peace in the head”: the constant, stressful thoughts about food have disappeared.
In addition to the injection, Badstübner adopted a strict program: changing his diet, exercising, and strict self-discipline. According to her plan, she actually wanted to stop taking the injection in the spring before the tennis season. And still maintain your weight.
But she has long been thinking about further changes. "It's fine-tuning now. Five kilos still have to go and my stomach still bothers me a lot," she says. She wants to achieve this with the tablet from Eli Lilly, which, unlike that of its Danish competitor Novo Nordisk, does not have to be taken on an empty stomach.
Her initial idea of maintaining the weight without support now seems more difficult than she thought. On the one hand, she fears the well-known yo-yo effect. On the other hand, she now doubts her own discipline. "Why should I torture myself? I'm lazy when it comes to that. Then I'd have to do abdominal exercises. But I just like to play tennis." But that's not a big deal for Badstübner. She sees it pragmatically. She has the money, the cost-benefit ratio is right. "A lot of people throw money away on unnecessary things. I know what I'm throwing it away on."
Does psychological dependency arise here?
What will it do in the long term if weight loss medications become everyday objects that fewer and fewer people want to live without? Is this already an addictive behavior?
Anja Hilbert, professor of behavioral medicine at Leipzig University Hospital, says that research so far has shown no evidence of an addiction that makes it difficult to stop taking weight-loss injections or pills. “You don’t feel high or have withdrawal symptoms.”
What is often misunderstood as withdrawal is the return of weight after stopping. “This is not an addiction phenomenon, but rather the expected course of a chronic illness whose treatment is stopped,” says Sabrina Kristic, senior partner at the strategy consultancy Boston Consulting Group.
It is proven how the drugs work: the active ingredients act in areas of the brain that control hunger, reward and motivation, explains Hilbert. “This has the effect of weakening the desire for food – especially highly rewarding foods – and weight can be reduced.”
Since the brain is highly interconnective, i.e. certain brain regions and networks do not work separately but rather with each other, other areas can also be affected by the active ingredients - for example those that are responsible for mood or addictive behavior.
Although there is little solid evidence, “we see in studies that mood improves with GLP-1,” says Hilbert. The fact that other addictions are reduced by the active ingredients could also be a positive side effect. According to researchers, the remedies could help people better control their cravings without completely giving up certain things. It wouldn't necessarily be about abstinence, but about a more moderate approach.
The longer Badstübner takes the weight loss injection, the quieter her other desires become. While there used to be eight to ten coffees a day, now there are only three. “In general, I feel much more consistent in all areas of life,” she says.
Initial research results support such observations. A study published in the journal “Lancet” in 2026 showed that weight loss medications reduce heavy alcohol consumption more significantly in people with alcohol dependence and obesity. Eli Lilly is also currently investigating whether its medications can help people with alcohol use disorder and obesity drink less.
Other positive effects are also known: GLP-1 drugs can reduce the risk of cardiovascular disease and stroke, reverse fatty liver disease, slow the progression of chronic kidney disease and even help with osteoarthritis. Badstübner's blood values are better today, and sugar and cholesterol have fallen, she says. She no longer has rheumatism attacks either. “It just makes me feel good,” says Badstübner.
But there are also indications of negative effects: The fact that GLP-1 influences our reward system and thus also the release of dopamine could also be problematic. Because the corresponding nerve cells are considered the center of our feeling of joy, when eating and drinking as well as during sex. The Danish scientist Jens Juul Holst, who was involved in the discovery of GLP-1, warned that life with these drugs could potentially become so monotonous that at some point you can no longer stand it and return to your old everyday life.
In any case, there is currently only research data for a short time horizon of up to around five years, says researcher Hilbert. Real long-term consequences, particularly on the psyche, have not yet been investigated.
However, there are known complaints regarding tolerability: fatigue, stomach pain, hair loss or dizziness. In rare cases, inflammation of the pancreas and possible vision problems can occur. The discontinuation rate for weight loss injections is currently up to 50 percent.
Hilbert estimates that this rate could be reduced by the pill - another positive development. Despite insufficient long-term research and further research into side effects, Hilbert thinks highly of the new medications. "I always think back to the time before GLP-1 drugs. What was on the market back then was nowhere near as effective or safe."
Kerstin Oltmanns, professor of psychoneurobiology at the University of Lübeck, who researches behavioral therapy against obesity, has a different opinion. “In my view, GLP-1s are anything but game changers,” she says. "You have to make it clear to yourself what is being conveyed here: you take a drug whose long-term effects on the brain are unclear instead of eating less? That's absurd." The long-term solution lies in psychotherapeutic addiction withdrawal and not in a pill, says Oltmanns.
The social consequences
There is a risk that weight loss medications will further increase social pressure to be thin. Hilbert also suspects this: “Especially if costs fall and medications become more widely available, the attribution of responsibility for one’s own weight could increase.”
Obesity is not the result of a lack of discipline. “It is a complex, multifactorial health disorder with a chronic course,” says Hilbert. The causes are diverse – genetic, psychological, social. “First the food industry makes us fat, and now the pharmaceutical industry comes along and invents really great drugs to make us thin again.”
This is proven by an Italian study from 2025, in which 22 percent of patients expressed the fear that they would never be able to stop taking the medication again. Concern about not being able to get off the medication is also one of the top topics in Reddit forums. Manuela Badstübner, who wanted to stop taking the medication a year ago in the fall, is now convinced that life without weight loss pills is “no longer imaginable.” In the end, a lot of things remain just a big social experiment.
