New Insights Into Semaglutide and Weight Loss

Semaglutide & Incretin Wonder-Drugs

Weight loss has been for decades a very lucrative market. From diet companies to books describing magic solutions or food supplements supposed to activate the metabolism. Most of these “solutions” were snake oil at best and dangerous at worst. But this did not stop people from trying them anyway.

The growth of this market has been parallel with the increase in obesity worldwide. It concerns up to 650 million people today.

This is why the arrival of semaglutide as an anti-obesity treatment has been a healthcare revolution. Obesity is tightly linked to many other metabolic diseases and overall increases the death rate significantly.

The global obesity treatment market size was estimé à $15.92B en 2024 et devrait atteindre $60.53B d'ici 2030, avec une croissance 22.31% CAGR.

Source: Grand View Research

Semaglutide, commercialized under the brand name Wegovy by Novo Nordisk (NVO + 5.77%), mimics a weight-related hormone called GLP-1 (glucagon-like peptide-1), but we are still not fully sure exactly what it does to our metabolism.

The same can be said for competing drugs like Eli Lilly’s (LLY + 0.48%) Mounjaro (Tirzepatide- both a GLP-1 receptor agonist and a GIP-analog), with all these drugs grouped under the name “incretins”.

A new study observing people taking incretins in everyday life settings (and not in a hospital or other more controlled environment), taking semaglutide, reveals that not only does the drug affect our metabolism, but also our taste perception. This might be important in better understanding the effect of the drug and its impact on obesity and behavior.

The study was conducted by doctors and scientists in Austria at the Medical University of Vienna and the University of Graz. It was published in Diabetes, Obesity, and Metabolism¹, sous le titre "Real-world insights into incretin-based therapy: Associations between changes in taste perception and appetite regulation in individuals with obesity and overweight: A cross-sectional study ».

How Do Incretins Work?

Semaglutide (Wegovy) has been shown to reduce body weight by approximately 15% compared to placebo over a treatment period of 68 weeks.

Tirzepatide (Mounjaro) has been shown to result in even greater weight loss than semaglutide, particularly at higher doses.

Initially, this effect was mostly assumed to be due to the molecules belonging to the incretin hormone class, which decrease blood glucose levels (they were initially invented as a diabetes therapy).

But it has since appeared that these drugs also have an effect on several other organs, like the heart, kidneys, and central nervous system.

Source: Frontiers In Molecular Biosciences

For the brain effects more specifically, GLP-1 drugs have been shown to influence food intake by targeting receptors located in multiple brain areas involved in taste perception, olfaction, and reward processing.

It seems that semaglutide not only reduces appetite but also affects dopamine-mediated reward signaling in the brain, which may explain the reduced food craving in patients.

Source: Dr. Ulrike Hövelmann

Now, a new factor in the reaction to incretin is becoming apparent: direct change in taste perception not from affecting the brain, but the taste signals in the tongue themselves.

Changing Taste With Incretins

Who Was Studied?

Some studies had already pointed to possible effects of semaglutide and incretins on taste, like a reduction in taste detection. But the results were overall not clear yet, and sometimes contradicted each other.

The new study included people suffering from obesity, with an initial body mass index (BMI) ≥30, or BMI between 27 and 30. They also had at least one weight-related comorbidity like prediabetes, type 2 diabetes mellitus, hypertension, dyslipidemia, obstructive sleep apnea, or cardiovascular disease.

All participants were required to be actively receiving treatment with a GLP-1 or dual GIP/GLP-1 receptor agonist and to have been on therapy for at least three consecutive months.

Qu'est-ce que l'étude a trouvé ?

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Approximately 20%–30% of participants reported increased taste perception in the sweet, salty, bitter, and sour tastes.

The participants with increased intensity in the sweet and salty taste were also the ones with stronger reduced cravings or earlier satiety (end of hunger).

However, this stronger change in taste for some patients did not correlate with BMI reduction, after adjusting for relevant covariates (other factors, like higher initial weight, for example).

So overall, the study indicates that changes in taste from taking semaglutide and other incretins are real, but might not have an impact on weight loss.

A hypothesis by the researchers to explain it is that the effect on taste perception is strong in the short term, but neutralized by compensation in metabolism or food intake volume in the long term.

New Possibilities For Obesity Therapies

New Hypothesis

These results could indicate a previously unknown link between taste perception and satiety, although the mechanism by which it works is still unknown.

Another possibility is that chemical sensors in the intestine, similar to taste buds, might also be affected, a previously unknown effect.

This opens the question that the difference in outcome between patients taking GLP-1 drugs might stem from differences in their genetic makeup and taste buds.

De plus amples recherches

New studies should focus on these new ideas, with, for example, a longer study from the start of incretin-based treatments, to study why the changes in taste stop impacting weight loss in the long run.

If this loss of effect could be addressed, it could significantly enhance the efficiency of all incretin drugs.

Figuring out why only some patients report a difference in taste perception could also help.

If this is due to genetic differences, this could help identify in advance which patients will benefit the most from semaglutide & incretin with a simple genomic test costing less than $1,000. If this is due to other factors, these too can be identified in advance to predict the pertinence of prescribing incretin better.

Investing In The Pharmaceutical Sector

Eli Lilly et compagnie

While the initial lead in obesity treatment using incretin was held by Novo Nordisk, the approvals of more complex molecules, adding extra incretin effects, have upended the market in favor of other companies.

L’un d’entre eux est Eli Lilly, un autre acteur majeur sur le marché des médicaments contre le diabète, avec une vaste expérience de travail avec les analogues de l’incrétine, la classe de molécules comprenant le GLP-1, le glucagon et le GIP.

Eli Lilly est désormais leader du marché des analogues de l'incrétine aux États-Unis, avec 53.3 % de parts de marché sur le total des prescriptions. L'entreprise a ainsi enregistré une croissance de son chiffre d'affaires de 45 % d'une année sur l'autre pour ses produits phares, qui incluent également des médicaments non liés au diabète et à l'obésité.

Source: Eli Lilly

Mounjaro/Zepbound is only a step on the way, with the additional effect of glucagon to be added to a new product in the future, if the clinical trials go well.

Un autre médicament potentiellement nouveau et important contre l’obésité est l’orforglipron, une version orale du GLP-1, qui serait plus facile à prendre que les médicaments actuels, basés sur des injections.

Pour répondre à la demande liée à ces ventes élevées, l'entreprise prévoit d'accroître considérablement ses capacités de production aux États-Unis, avec un investissement total de 50 milliards de dollars. Eli Lilly prévoit également d'augmenter ses dépenses de R&D de 8 %.

It should be noted that Eli Lilly is a more diversified company than Novo Nordisk, with a pipeline on Alzheimer’s, Parkinson’s, cancer, autoimmune diseases (Crohn’s, Rheumatoid Arthritis, Multiple Sclerosis), etc.

Source: Eli Lilly

Alors que les médicaments contre l’obésité et le diabète deviennent le cœur des revenus de l’entreprise, ces segments devraient également être pris en compte par les investisseurs potentiels.

(Vous pouvez lire a more detailed analysis of Eli Lilly’s activities in our dedicated investment report.

Vous pouvez également lire notre article sur le «Principales entreprises dans le domaine des traitements de l'obésité".)

Dernières actualités et développements concernant l'action Eli Lilly (LLY)

Étude référencée

^{1. Ali Kapan, Othmar Moser, Richard Felsinger, Thomas Waldhoer, Sandra Haider. Real-world insights into incretin-based therapy: Associations between changes in taste perception and appetite regulation in individuals with obesity and overweight: A cross-sectional study. Diabetes, Obesity, and Metabolism. 24 June 2025. https://doi.org/10.1111/dom.16548}