On September 8, 2026, Structure Therapeutics released topline data from a Phase 1/2a study of ACCG-2671 — and called it the first reported clinical data for an oral small-molecule amylin receptor agonist. A single 10 mg dose was reported to produce a 3.3% mean body-weight reduction by day 24 in healthy adults, with a company-estimated half-life of roughly six days.
The number itself is modest. What makes it worth reading is the shape of it: one dose, three weeks of effect, from a pill. Every amylin compound with meaningful human weight-loss data so far — cagrilintide, petrelintide, eloralintide — is an injectable peptide. If an orally dosed small molecule can engage the same receptor, the amylin category stops being an injection-only category. Here is what was actually reported, what it does not show, and which amylin compounds are sourceable today.
Research-context information only. ACCG-2671, aleniglipron, and the research peptides discussed below are investigational and not approved by the FDA for the uses described. Trial figures reported here come from company announcements. This article reports what has been documented; it is not a protocol and not a recommendation. Possession or use of investigational compounds outside an authorized clinical trial may be illegal in your jurisdiction. Consult a licensed physician for personal medical decisions.
What Structure Actually Reported
The ACCG-2671 data come from the single-ascending-dose (SAD) portion of a Phase 1/2a trial. Thirty-one healthy adults without obesity received a single dose of 1, 2, 5 or 10 mg — or placebo.
| Endpoint | Reported result |
|---|---|
| Body weight, day 24 (single 10 mg dose) | 3.3% mean reduction |
| Estimated half-life | ~6 days (company frames this as supporting once-weekly dosing) |
| Time to peak concentration | 1–1.5 hours |
| Exposure | Dose-proportional across 1–10 mg |
| CTX-1 (bone resorption marker), day 2 | ~60% decrease |
| Serious adverse events | None reported |
| Drug-related discontinuations | None reported |
| Drug-induced liver injury | None reported |
| Nausea / vomiting | None at 1–2 mg; 4 of 5 nausea and 3 of 5 vomiting at 5 mg; all 6 participants affected at 10 mg |
Two details deserve more weight than the headline percentage.
The first is the half-life. Roughly six days is unusual for an orally dosed small molecule — most are cleared in hours, which is why oral GLP-1 programs are built around once-daily dosing. A six-day half-life is the reason a single administration was still moving body weight three weeks later, and it is the basis for the company's stated once-weekly ambition.
The second is the CTX-1 signal. CTX-1 is a marker of bone resorption, and the calcitonin arm of amylin-receptor pharmacology is known to suppress it. A ~60% drop by day two is being read by the company as direct evidence of target engagement rather than as an efficacy endpoint in itself — it shows the molecule is hitting the receptor family it was designed to hit.
The tolerability table is the honest counterweight. GI effects were dose-related and, at 10 mg, universal in that small cohort. That is the same wall every incretin and amylin program runs into, and single-dose data in healthy volunteers is the least informative setting for judging whether titration solves it.
Why the Oral Amylin Question Matters
Amylin has become the obesity field's second lever. It is a 37-amino-acid hormone co-secreted with insulin that slows gastric emptying, blunts post-meal glucagon, and signals satiety through the hindbrain — a mechanism entirely separate from GLP-1, GIP or glucagon receptor agonism. That separation is why the category attracted capital: amylin can be run standalone for people who cannot tolerate incretin doses, or layered on top of a GLP-1 to push past a plateau.
It has also, so far, been an injectable category. Peptides do not survive the gut without heavy formulation work, which is why petrelintide and eloralintide are both subcutaneous, and why the amylin analog you can actually source today — cagrilintide — is reconstituted and injected like every other research peptide.
A non-peptide small molecule sidesteps that constraint entirely. It is the same structural trade the oral GLP-1 field made when it moved from peptide-based oral semaglutide to small molecules like orforglipron: give up the peptide's receptor selectivity and potency in exchange for a molecule that can be manufactured cheaply, shipped without cold chain, and swallowed. The oral-versus-injectable trade-off is covered in more depth in our oral GLP-1 vs injectable comparison.
Where the Amylin Field Stands
| Compound | Company | Type | Route | Stage |
|---|---|---|---|---|
| Cagrilintide | Novo Nordisk | Amylin analog peptide | Injectable | Phase 3 as part of CagriSema; NDA submitted |
| Petrelintide | Zealand / Roche | Amylin analog peptide | Injectable | Phase 2b data reported at ADA 2026 |
| Eloralintide | Eli Lilly | Selective amylin agonist peptide | Injectable | Phase 2 data reported 2026 |
| VK3019 | Viking | Amylin/calcitonin (DACRA) peptide | Injectable | Phase 1 SAD started June 2026 |
| ACCG-2671 | Structure | Non-peptide small molecule | Oral | Phase 1/2a SAD reported Sept 2026; MAD dosing underway |
The table is the story. Four injectable programs are ahead of ACCG-2671 on the development timeline, and two of them already have multi-week efficacy data in people with obesity. Structure is behind on stage but alone on route. Whether that matters depends entirely on the 12-week multiple-ascending-dose readout — a single dose in healthy volunteers tells you almost nothing about what sustained oral amylin dosing does to body composition.
What This Means for Peptide Buyers Today
ACCG-2671 is a Phase 1 asset held by one company. It is not sold by any research vendor, will not be for years, and anything advertised under that code should be treated as a red flag. The read-through to what is actually sourceable runs through the amylin mechanism, not the molecule.
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- Cagrilintide remains the only amylin agonist widely stocked by research peptide vendors, and it is the compound the whole amylin category is benchmarked against. Current COA-verified pricing and coupon codes are compared in the cagrilintide buying guide, with mechanism and effect context in cagrilintide vs semaglutide and administration detail in the cagrilintide dosing guide.
- Retatrutide + cagrilintide is the stack that gets asked about most when amylin data lands, because it pairs the triple agonist with the amylin lever. See the retatrutide + cagrilintide stack buying guide for how vendors price the pair.
- Retatrutide, semaglutide and tirzepatide are still the most accessible incretin compounds if you want the mechanism with the deepest human dataset. Vendor comparisons: retatrutide, semaglutide, tirzepatide.
For the full vendor landscape and every active discount code across the metabolic category, see the deals page.
