GLP-1 Medications: The Trend, the Mechanism, and the Possible Yo-Yo Effect
Many health trends come and go. With the current GLP-1 medications used for weight reduction, the situation is different. Medical mechanisms meet emotionally charged topics such as self-control, body weight, health, and cost.
To understand how and why these drugs work, why discontinuation is often followed by weight regain, and why the market is expanding so rapidly, one must look beyond the headlines.
From Diabetes Treatment to Weight Reduction Phenomena
Medications containing the active substances semaglutide and tirzepatide are currently in high demand. These drugs were not originally developed as lifestyle diet solutions.
Semaglutide is known under the brand name Ozempic®, originally approved for diabetes treatment and later, at a higher dosage, approved as Wegovy® for weight reduction. Both are products of the Danish pharmaceutical company Novo Nordisk.
Tirzepatide, developed by Eli Lilly, followed a similar path: first approved as Mounjaro® for type 2 diabetes, and later as Zepbound® for obesity treatment.
The initial focus on the United States also had economic advantages, as the U.S. represents the largest market worldwide for obesity and diabetes treatment.
What These Medications Actually Accomplish
To explain how these active substances exert their effect (Drucker, 2018), we need to dig a little deeper:
Semaglutide acts on GLP-1. GLP-1 is a hormone that is naturally produced in the intestine and influences hormonal blood glucose regulation, delays gastric emptying, and modulates the satiety center in the brain. These are precisely the mechanisms that are disturbed or overloaded in obesity and type 2 diabetes.
The mechanism of action of tirzepatide differs slightly, as it activates not only the GLP-1 receptor but also the GIP receptor. GIP is a hormone from the same hormone family as GLP, and its activation interferes in an even more complex way with hormonal metabolic regulation (Jastreboff et al., 2022). This also explains why these active substances are effective in both diabetes and obesity.
These GLP-1 medications are therefore not an isolated “weight issue.” Studies show that weight reduction under GLP-1 therapy is associated with significant improvements in cardiometabolic parameters — blood glucose levels, blood pressure, and lipid levels (Wilding et al., 2021).
On the “Yo-Yo” Effect
As already described in the previous articles, obesity and type 2 diabetes are chronic diseases, not merely lifestyle phenomena. The body actively regulates weight, hunger, and energy expenditure through hormonal mechanisms. This is precisely why weight often “returns” after dieting — and precisely why GLP-1-based medications are so effective: they interfere with this hormonal counter-regulation. That weight is often regained after discontinuation is therefore logical in this context. It reflects the unfortunately chronic nature of obesity and diabetes (Rubino et al., 2022).
With GLP-1 medications it should not be about aesthetics; it is about influencing exactly those mechanisms that characterize these two diseases.
Forms of Administration (Soon Not Only Injections?)
These medications are injected subcutaneously once per week. Semaglutide is also available in tablet form — however, so far only approved for the treatment of type 2 diabetes and not for obesity treatment. These tablets must be taken daily and are significantly less effective in terms of body weight than the high-dose injectable forms. Oral high-dose versions for obesity treatment are currently in development but are not yet an established clinical standard (FDA, 2019; Drucker, 2018).
On the Economics
Prices typically fall within the following ranges, depending on dosage and product:
· Semaglutide (Wegovy®): approx. €300–370 per month
· Tirzepatide (Mounjaro®): approx. €400–500 per month
(Product information Wegovy®, 2023; Product information Mounjaro®, 2025).
In the United States, prices are in some cases significantly higher.
When medications are required long term, this creates an economically highly attractive model: chronic indications mean recurring prescriptions. This is precisely why this market is currently one of the fastest-growing in the pharmaceutical sector — and why conventional medicine and pharmacology often focus on symptom management rather than addressing root causes.
On the Lack of Coverage by Health Insurance
In Germany, statutory health insurance currently does not cover these medications when used solely for obesity treatment. If the active substances are prescribed as part of diabetes therapy, statutory insurance may cover the costs (§34 SGB V).
Private insurers decide on coverage individually in both cases (§192 para. 1 VVG).
GLP-1 Medications: Not a Diet Trend, but an Intervention in Biology
Anyone who views these medications merely as aids for losing weight is missing the point. These GLP-1 medications are not a lifestyle phenomenon and not a short-term hype. They work by intervening in central hormonal regulatory circuits that are out of balance in obesity and type 2 diabetes. This is exactly where their strength lies — and at the same time the reason why the effect often does not persist after discontinuation. Ultimately, this too comes down to the need for sustainable changes in habits.
FAQ – Frequently Asked Questions About GLP-1 Medications
1. What side effects occur most frequently with GLP-1 medications — and why?
The most common side effects include nausea, a feeling of fullness, vomiting, and diarrhea. These do not result from “intolerance,” but are direct consequences of delayed gastric emptying and altered hormonal signaling in the digestive tract. The body first has to adapt to this changed gastrointestinal dynamic.
2. Is there evidence that these active substances also influence inflammatory processes in the body?
There is evidence that GLP-1-based therapies can reduce inflammatory markers and cardiometabolic risk factors. This explains why blood pressure, blood glucose, and lipid levels often improve in parallel.
3. Why do some people lose significantly more weight with these medications than others?
Individual response depends on genetic factors, the degree of insulin resistance, gut hormones, eating behavior, and baseline weight. Not every body responds equally strongly to hormonal modulation.
4. Can accompanying lifestyle changes reduce the likelihood of regaining weight after discontinuation?
Yes, people who make sustainable changes to their diet, physical activity, and sleep patterns have a better chance of maintaining their weight after therapy ends.
5. Why are these medications often described as “game changers” in obesity treatment?
Because they directly interfere with the hormonal counter-regulation that previously caused many diets to fail. They address a biological mechanism, not only behavior.
6. Are there groups of people for whom these medications are clearly unsuitable?
Yes, this includes people with certain thyroid disorders, severe gastrointestinal diseases, or a history of pancreatitis. Medical evaluation is therefore essential.
Additional information on metabolic disorders and many other topics can be found in the articles on our blog, the volumes of our “Codex Humanus”, and the “Medizinskandale” series. You are welcome to visit our online shop.
Sources:
· U.S. Food and Drug Administration (2017): „Ozempic (semaglutide) injection – Prescribing Information“ (Label)
· U.S. Food and Drug Administration (2021): „Wegovy (semaglutide) injection – Prescribing Information“ (Label)
· https://www.fortunebusinessinsights.com/anti-obesity-drugs-market-104783
· https://www.fortunebusinessinsights.com/industry-reports/diabetes-drugs-market-100570
· U.S. Food and Drug Administration (2022): „Mounjaro (tirzepatide) injection – Prescribing Information“ (Label).
· U.S. Food and Drug Administration (2023): „Zepbound (tirzepatide) – Prescribing Information“ (Label).
· Drucker, D. J. (2018): „Mechanisms of Action and Therapeutic Application of Glucagon-like Peptide-1“, Cell Metabolism.
· Jastreboff, A. M. et al. (2022): „Tirzepatide Once Weekly for the Treatment of Obesity“, New England Journal of Medicine.
· Wilding, J. P. H. et al. (2021): „Once-Weekly Semaglutide in Adults with Overweight or Obesity“, New England Journal of Medicine.
· Rubino, D. et al. (2022): „Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension“, Diabetes, Obesity and Metabolism.
· U.S. Food and Drug Administration (2019): „Rybelsus (semaglutide) tablets – Prescribing Information“ (Label).
· Novo Nordisk (2023): Wegovy® (Semaglutid) – Fachinformation, Stand: 04/2023.
· Eli Lilly and Company (2025): Mounjaro® (Tirzepatid) – Fachinformation, Stand: 10/2025.
· Sozialgesetzbuch (SGB V) – § 34.
· Versicherungsvertragsgesetz (VVG) – § 192 Abs. 1.