The new GLP-1 and amylin treatment has produced striking early results, but the headlines may have arrived before the evidence
Written by Injector Rick, founder and aesthetic practitioner at BONAVADA Aesthetics in Worthing.
Just as everybody finally learned how to pronounce semaglutide, tirzepatide and retatrutide, the pharmaceutical industry presented us with amycretin.
Then it changed the name to zenagamtide.
Because apparently the first stage of every new weight-loss treatment is making sure nobody can confidently ask for it at the chemist.
Early trials have reported average weight loss of more than 20%, leading to predictable claims that amycretin could be the next Ozempic or even better than Mounjaro, or maybe even better than Retatrutide.
So, is it?
The quick answer
Amycretin, now called zenagamtide, looks extremely promising, but we cannot yet say that it is better than Mounjaro, Wegovy, Ozempic or maybe Retatrutide.
An early injectable study reported average weight loss of up to 24.3% after 36 weeks. A tablet version previously produced average weight loss of 13.1% after 12 weeks.
Those are impressive figures, but the studies were relatively small and were not direct comparisons with existing weight-loss medicines. Larger phase 3 trials are now underway, including a planned head-to-head comparison with semaglutide.
In other words:
Very exciting. But not yet ready to collect its winner’s trophy.
What is amycretin?
Amycretin was the original development name for a new medicine created by Novo Nordisk, the company behind Ozempic and Wegovy.
Its official name is now zenagamtide.
It is being developed as both:
- a once-weekly injection
- a daily tablet
Unlike semaglutide, which primarily targets the GLP-1 receptor, zenagamtide combines activity at the GLP-1 and amylin receptors within one molecule. Novo Nordisk has now moved it into phase 3 development for weight management.
How does zenagamtide work?
GLP-1 helps reduce appetite, improve feelings of fullness and regulate blood glucose. It also slows the rate at which food leaves the stomach.
Amylin is another hormone involved in appetite and blood-sugar control. It is naturally released alongside insulin after eating and helps signal that you have had enough.
Zenagamtide activates both systems.
A simple way to picture it is:
GLP-1 starts closing the buffet, while amylin begins stacking the chairs.
This differs from:
- semaglutide, which targets GLP-1
- tirzepatide, the medicine in Mounjaro, which targets GLP-1 and GIP
- retatrutide, an experimental medicine targeting GLP-1, GIP and glucagon
Having more targets does not automatically make one drug better. The final result depends on effectiveness, side effects, dosing, discontinuation rates and what happens when thousands of people use it for several years.
Pharmacology is slightly more complicated than simply collecting hormones like Pokémon Go.
What did the amycretin research find?
The main injectable study involved 125 adults with overweight or obesity.
Participants received different doses of weekly amycretin or a placebo. The estimated average changes in body weight included:
- 24.3% loss with the highest 60 mg dose after 36 weeks
- 22% loss with the 20 mg dose after 36 weeks
- 16.2% loss with 5 mg after 28 weeks
- 9.7% loss with 1.25 mg after 20 weeks
The most common side effects were gastrointestinal and were generally described as mild or moderate. However, the study also had a high number of withdrawals, many reportedly for reasons unrelated to treatment side effects (Dahl et al., 2025).
A separate early trial investigated oral amycretin. The highest-dose group achieved an estimated average weight loss of 13.1% after 12 weeks (Gasiorek et al., 2025).
That is undeniably interesting.
It is also important to remember that early trials are partly designed to test doses and detect immediate safety problems. They cannot establish what happens after five years, how many people tolerate long-term treatment or whether the results will be repeated in a much larger and more varied population.
Is amycretin better than Mounjaro?
We do not know.
Comparing percentages from separate trials can be misleading because the studies may involve different:
- participants
- treatment periods
- doses
- withdrawal rates
- lifestyle programmes
- methods of calculating results
A 24% result in one early trial does not automatically beat a lower number from a completely different study.
Clinical trials are not Eurovision. You cannot simply place the percentages beside one another and award Denmark twelve points.
There is currently no completed direct trial proving that zenagamtide produces more weight loss than Mounjaro.
Is it better than Ozempic or Wegovy?
Again, we do not know yet.
Ozempic and Wegovy both contain semaglutide, although they are authorised for different indications and use different dosing arrangements.
A phase 3 study called AMAZE 7 is planned to compare once-weekly zenagamtide directly with once-weekly semaglutide in approximately 650 adults with obesity.
The study is expected to begin in September 2026 and reach completion in 2028. That should tell us considerably more than comparing pharmaceutical press releases and social-media headlines.
What are the possible side effects?
The early injectable and oral studies mainly reported gastrointestinal effects, similar to those commonly associated with GLP-1-based medicines.
These can include:
- nausea
- vomiting
- diarrhoea
- constipation
- abdominal discomfort
- reduced appetite
In the first oral study, all reported treatment-emergent adverse events were classed as mild or moderate, but side effects became more frequent as doses increased (Gasiorek et al., 2025).
Larger trials are still needed to identify uncommon complications and establish how tolerable the medicine is during prolonged use.
A treatment can produce outstanding weight loss on paper and still be unsuccessful if half the patients cannot remain on it.
Is amycretin available in the UK?
No.
Zenagamtide remains an investigational medicine and is not currently available as an approved routine treatment in the UK.
Its phase 3 weight-management programme is underway, with major trials expected to continue through 2028 and beyond.
Any website claiming to sell genuine amycretin or zenagamtide to the public now should therefore be treated with extreme caution.
A vial carrying the right name is not necessarily the authorised medicine. Printers have also made excellent progress.
Frequently asked questions
Are amycretin and zenagamtide the same thing?
Yes. Amycretin was the original development name. Novo Nordisk now calls the medicine zenagamtide.
Is amycretin another GLP-1?
It includes GLP-1 activity, but it also activates amylin receptors. It is described as a single-molecule GLP-1 and amylin receptor agonist.
Will amycretin be an injection?
Both injected and oral versions are being developed.
How much weight could people lose?
An early injectable study reported estimated average weight loss of up to 24.3% after 36 weeks. This does not guarantee that every patient would achieve that result.
When could amycretin become available?
There is no confirmed UK launch date. Important phase 3 trials are expected to continue until at least 2028, after which regulatory review would still be required.
Can I buy amycretin online now?
There is no authorised retail version currently available. Products advertised online as amycretin may be unauthorised, incorrectly dosed, contaminated or entirely different from the medicine used in clinical trials.
My honest opinion
Amycretin, or zenagamtide, may become one of the most important next-generation weight-management treatments.
The mechanism is credible, the oral and injectable options are interesting, and the early weight-loss results deserve attention.
But the honest conclusion is still:
It may eventually prove better than existing treatments, but it has not done so yet.
We need phase 3 results, direct comparisons, longer follow-up and far more information about tolerability before declaring it the new boss of weight-loss medication.
At BONAVADA Aesthetics, I do not prescribe weight-loss medicines. However, I follow these developments because major weight loss can, and does, affect facial volume, skin laxity and the types of aesthetic concerns clients later bring into the clinic.
For now, zenagamtide belongs firmly in the category of fascinating, promising and certainly not something you should be ordering from a country you’ve never heard, of or buying from a stranger round the back of Tescos.
Written by Injector Rick, founder and aesthetic practitioner at BONAVADA Aesthetics in Worthing.
Because apparently losing weight may soon be easier than pronouncing the medication.
References
Dahl, K. et al. (2025) ‘Amycretin, a novel, unimolecular GLP-1 and amylin receptor agonist administered subcutaneously: results from a phase 1b/2a randomised controlled study’, The Lancet, 406(10499), pp. 149-162. Available at:
https://pubmed.ncbi.nlm.nih.gov/40550231
Gasiorek, A. et al. (2025) ‘Safety, tolerability, pharmacokinetics, and pharmacodynamics of the first-in-class GLP-1 and amylin receptor agonist, amycretin: a first-in-human, phase 1, double-blind, randomised, placebo-controlled trial’, The Lancet, 406(10499), pp. 135-148. Available at:
https://pubmed.ncbi.nlm.nih.gov/40550229
Novo Nordisk (2026) Innovation and therapeutic focus: zenagamtide, formerly known as amycretin. Available at:
ClinicalTrials.gov (2026) AMAZE 7: Efficacy and safety of once-weekly zenagamtide compared with once-weekly semaglutide in participants with obesity. Available at: