Amycretin Pill vs Orforglipron: Which Oral Drug Has Better Weight-Loss Trial Results?
Written by Dan Cripe, RN, BSN & Marcia Cripe, RN
If you look only at the headline numbers, oral amycretin has produced the more dramatic early weight-loss result. In its first obesity study, the highest oral amycretin dose was associated with a 13.1% average reduction in body weight after just 12 weeks.
Orforglipron has produced substantial weight loss too, but its strongest evidence comes from much larger and longer trials. In the Phase 3 ATTAIN-1 obesity trial, the highest studied dose produced an average 11.2% weight reduction at 72 weeks using the trial's treatment-regimen analysis.
That sounds like an easy win for amycretin.
It isn't.
The studies were conducted at different phases of development, with very different numbers of participants, doses, treatment durations, and statistical methods. There has never been a head-to-head trial of oral amycretin versus orforglipron, so the current numbers cannot tell us which drug will ultimately produce more weight loss.
There is another major difference as of September 2026: orforglipron is already FDA-approved for chronic weight management under the brand name Foundayo. Amycretin, now also called zenagamtide in Novo Nordisk's development program, remains investigational.
These Are Not Two Versions of the Same GLP-1 Pill
Amycretin and orforglipron both come in oral formulations, but biologically they are very different drugs.
Orforglipron is a small-molecule GLP-1 receptor agonist. It targets the GLP-1 receptor without using the peptide structure found in medications such as semaglutide.
Amycretin combines two pathways in one molecule. It activates both GLP-1 and amylin receptors.
Amylin is another hormone involved in appetite and satiety. Combining amylin and GLP-1 activity is one reason amycretin has generated so much interest as a potential next-generation obesity treatment.
But a more complex mechanism does not prove better clinical results.
That still has to be demonstrated in large trials.
What Did the Oral Amycretin Trial Actually Show?
The original oral amycretin study was a Phase 1 trial, designed primarily to evaluate safety, tolerability, and how the drug behaves in the body.
The weight-loss results were exploratory, but they were difficult to ignore.
After 12 weeks, average body-weight changes were approximately:
The highest oral dose therefore produced about 13.1% average weight loss in only 12 weeks.
And importantly, weight loss had not clearly plateaued by the end of the study.
Those are extremely promising early results.
But there is a giant asterisk attached to them: this was a very small early-phase study.
The groups used to evaluate those oral doses contained only a small number of participants. Phase 1 trials are excellent for identifying a signal worth pursuing, but they are not where we decide how well a medication will ultimately perform across thousands of people.
Amycretin Has More Oral Data Now — and the Number Is Different
Novo Nordisk later tested both injectable and oral amycretin in a Phase 2 study involving 448 people with type 2 diabetes.
In that trial, oral amycretin produced weight loss of up to 10.1% at 36 weeks, compared with 2.5% with placebo.
That number is lower than the 13.1% seen during the earlier 12-week obesity study.
It does not mean amycretin suddenly became less effective.
The studies involved different participants, different clinical goals, and different dose-escalation strategies. People with type 2 diabetes also often lose less weight in obesity-drug trials than people without diabetes.
This is exactly why comparing percentages across unrelated trials can get misleading very quickly.
What Did Orforglipron Show in Phase 3?
Orforglipron has moved much further through clinical development.
The ATTAIN-1 Phase 3 trial enrolled more than 3,100 adults with obesity without diabetes and followed them for 72 weeks.
Average weight reduction was:
At the highest studied dose, more than half of participants lost at least 10% of their starting weight.
About 36% lost at least 15%, and 18.4% lost at least 20%.
Those results may look less dramatic than amycretin's 13.1% at 12 weeks. But the orforglipron data come from a much larger Phase 3 trial designed specifically to establish efficacy and safety in the population the medication was intended to treat.
That carries considerably more weight than an early Phase 1 signal.
Wait — Didn't Orforglipron Produce Almost 15% Weight Loss in an Earlier Trial?
Yes, and this is another reason you have to be careful when comparing drug headlines.
In an earlier Phase 2 obesity trial, participants taking some orforglipron doses lost as much as 14.7% of their body weight after 36 weeks.
That study involved only 272 participants.
When the medication moved into the much larger Phase 3 ATTAIN-1 trial, the average loss at the highest dose was 11.2% under the primary treatment-regimen analysis.
This does not mean the Phase 2 trial was wrong. Early studies often produce results that change when the medication is tested in larger and more diverse groups under a different protocol.
Amycretin still has to go through that same process.
Why You Cannot Compare 13.1% at 12 Weeks With 11.2% at 72 Weeks
At first glance, this seems backwards.
If amycretin produced 13.1% weight loss in 12 weeks while orforglipron produced 11.2% after 72 weeks, shouldn't amycretin obviously be stronger?
No.
The numbers came from completely different experiments.
The amycretin number tells us the drug has a very strong early efficacy signal.
The orforglipron number tells us much more about how that medication performs across a large obesity population over long-term treatment.
Those are different kinds of evidence.
Is Amycretin's Fast Early Weight Loss Still Important?
Absolutely.
Losing an average of 13.1% of starting body weight in 12 weeks is enough to make researchers pay attention, especially because the curve had not clearly flattened by the end of treatment.
Amycretin's dual GLP-1 and amylin mechanism also gives researchers a scientifically interesting reason to investigate whether it could eventually produce greater weight loss than GLP-1-only oral medications.
But we should not turn promising into proven.
As nurses, this is where we think drug-development headlines need some restraint. An exciting Phase 1 result should make you want to see the Phase 3 trial—not skip ahead and assume you already know how the Phase 3 trial will end.
Amycretin Is Now in Phase 3
Novo Nordisk has moved amycretin into its Phase 3 AMAZE obesity program.
The program includes both injectable and oral development. Novo has identified AMAZE 9 as a 72-week Phase 3 obesity trial specifically evaluating oral amycretin against placebo.
That trial will give us something the current evidence does not provide: large-scale, long-duration weight-loss data for the oral formulation.
Other Phase 3 amycretin studies are also evaluating the drug across obesity and related conditions.
Until those trials report, amycretin's position among oral weight-loss medications remains unsettled.
Orforglipron Has Already Crossed the Approval Line
Orforglipron no longer has that uncertainty about whether it can make it through an obesity-development program.
The FDA approved it on April 1, 2026, under the brand name Foundayo for long-term weight management in adults with obesity or adults with overweight and at least one weight-related condition.
It is a once-daily tablet and can be taken with or without food.
That matters when comparing it with investigational drugs.
Amycretin may eventually produce greater average weight loss. But today, orforglipron has something amycretin does not: completed Phase 3 evidence, an FDA review of its benefit-risk profile, an approved prescribing label, and real-world availability through prescription.
What About Side Effects?
Both drugs have produced the gastrointestinal side effects we have come to expect from medications that strongly affect appetite and gastrointestinal signaling.
With oral amycretin, nausea and vomiting were common in the early Phase 1 study, particularly at higher doses.
Orforglipron also produced mainly gastrointestinal side effects in Phase 3, with nausea, diarrhea, constipation, vomiting, and dyspepsia among the kinds of events seen during treatment.
Comparing tolerability directly would be just as problematic as comparing the weight-loss percentages.
Amycretin's current oral safety database is much smaller, while orforglipron has now been studied across large Phase 3 programs.
We will know much more about amycretin's real tolerability once thousands rather than dozens of people have taken the oral formulation for longer periods.
So Which Pill Has the Better Weight-Loss Trial Results?
It depends on what you mean by better.
If you mean the most impressive weight-loss percentage seen early in development, oral amycretin wins right now. Its 13.1% average weight reduction after only 12 weeks is an unusually strong early result.
If you mean the strongest evidence supporting sustained weight loss in a large population, orforglipron wins easily right now. It has completed large Phase 3 obesity trials and has FDA approval.
Those statements can both be true.
What we cannot say yet is that amycretin causes more weight loss than orforglipron.
Only a direct head-to-head trial—or at minimum mature Phase 3 amycretin data that allow a more meaningful comparison—could get us much closer to that answer.
The Bottom Line
Oral amycretin has produced the more eye-catching early weight-loss number: 13.1% in 12 weeks. Orforglipron produced 11.2% average weight loss at 72 weeks in its large Phase 3 ATTAIN-1 trial.
But putting those numbers side by side without context would be misleading.
Amycretin's result came from a small Phase 1 obesity trial. Orforglipron's came from a Phase 3 trial involving more than 3,000 people, and the medication is now FDA-approved as Foundayo.
So there is no legitimate winner yet.
Amycretin may eventually prove to be the more powerful oral weight-loss drug. Its combination of GLP-1 and amylin activity makes its early results particularly interesting.
For now, though, amycretin has the stronger early signal. Orforglipron has the stronger evidence.
The Phase 3 oral amycretin program is what will tell us whether those two things eventually become the same.
Sources
- Gasiorek A, Heydorn A, Gabery S, et al. 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. 2025;406(10499):135–148. PMID: 40550229. DOI: 10.1016/S0140-6736(25)01176-6.
https://pubmed.ncbi.nlm.nih.gov/40550229/ - Novo Nordisk. Novo Nordisk phase 2 trial with amycretin reports significant weight loss and HbA1c reduction in type 2 diabetes. November 25, 2025.
https://www.novonordisk.com/news-and-media/news-and-ir-materials/news-details.html?id=916463 - Novo Nordisk. Annual Report 2025 — Innovation and Therapeutic Focus. 2026.
https://annualreport.novonordisk.com/2025/strategic-aspirations/innovation-and-therapeutic-focus.html - Novo Nordisk. R&D Investor Event: Amycretin Phase 3 Development Programme. June 22, 2025.
https://www.novonordisk.com/content/dam/nncorp/global/en/investors/pdfs/ada/novo-nordisk-r-and-d-investor-event.pdf - Wharton S, Aronne LJ, Stefanski A, et al.; ATTAIN-1 Trial Investigators. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment. New England Journal of Medicine. 2025;393:1796–1806. DOI: 10.1056/NEJMoa2511774.
https://www.nejm.org/doi/10.1056/NEJMoa2511774 - Wharton S, Blevins T, Connery L, et al. Daily Oral GLP-1 Receptor Agonist Orforglipron for Adults with Obesity. New England Journal of Medicine. 2023;389:877–888. DOI: 10.1056/NEJMoa2302392.
https://www.nejm.org/doi/full/10.1056/NEJMoa2302392 - U.S. Food and Drug Administration. FDA Approves First New Molecular Entity Under National Priority Voucher Program. April 1, 2026.
https://www.fda.gov/news-events/press-announcements/fda-approves-first-new-molecular-entity-under-national-priority-voucher-program - U.S. Food and Drug Administration. Foundayo (orforglipron) Prescribing Information. 2026.
https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/220934s003lbl.pdf