Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

GSBR-1290 (aleniglipron): what the evidence says

Name: GSBR-1290 (aleniglipron)
Published: 2026-10-27

At a glance

What it is: Caution Not a peptide. Aleniglipron (GSBR-1290) is a once-daily oral small-molecule GLP-1 receptor agonist from Structure Therapeutics, not an amino-acid chain. It is listed here only because it is sold alongside research peptides. ^R1

What the evidence says: Human in the 36-week ACCESS phase 2b trial (230 adults), weight fell 8.2% to 11.3% more than on placebo, depending on dose. ^R1 Phase 3 trials started in Aug 2026. ^{R2, R3, R4}

Biggest risks: stomach and gut side effects; 10.4% stopped because of treatment-related effects. No drug-induced liver injury was seen in the phase 2b. ^R1

Rating


Human Human evidence	Limited: one phase 2b RCT (n = 230) ^R1
Animal Animal / lab evidence	Not reviewed
Regulatory	Investigational · not FDA-approved · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page ^{R5, R6, R7} · not named on WADA's 2026 list; as a drug not approved anywhere for human use it falls under S0 (non-approved substances) ^R8
Established human dose	No (trial amounts only; see Study details)

Evidence verdict: Weight loss: Limited (one 36-week phase 2b RCT, n = 230) · Type 2 diabetes: No published results · Other uses: No human data

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: one well-run, company-funded phase 2b trial is the only peer-reviewed efficacy result. The longer 72-week figures come from a company press release, not a journal.

What is it?

Related pages: orforglipron, ct-996, danuglipron, semaglutide.

Does it work?

How it compares with other GLP-1 drugs on this site

Small-molecule GLP-1 pills (aleniglipron, orforglipron, CT-996, danuglipron) are built to be absorbed from the gut; peptide GLP-1 drugs such as semaglutide and liraglutide are amino-acid chains, mostly injected. ^R9
Orforglipron, also a small molecule, was FDA-approved as Foundayo on Apr 1, 2026. ^R10
Danuglipron (Pfizer) was dropped in Apr 2025 after a possible liver-injury case in one participant. ^R11

Results

Human ACCESS (phase 2b, 36 weeks, n = 230): placebo-adjusted weight change −8.2%, −9.8% and −11.3% at the three target doses, with no plateau by week 36. ^{R1, R12}
Unknown Open-label extension: up to 16.2% weight loss at 72 weeks, company-reported and not peer-reviewed. ^R4
Unknown Earlier phase 1b/2a in type 2 diabetes and obesity: completed; peer-reviewed results not found. UNVERIFIED ^R13

Is it safe?

Human Stomach and gut effects were mostly mild to moderate and eased over time; 10.4% across dose groups stopped for treatment-related reasons. ^R1
Human No drug-induced liver injury in the phase 2b. This matters because a possible liver-injury case ended development of danuglipron. ^{R1, R11}
Long-term and rare risks unknown.

Pipeline status (investigational)

Sponsor: Structure Therapeutics (Gasherbrum Bio). ^R12
Trials: ACCESS phase 2b, completed ^R12; ACCOMPLISH-1 (3,600 planned) and ACCOMPLISH-2 (1,100 planned, type 2 diabetes) phase 3, recruiting since Aug 2026. ^{R2, R3, R4}
Expected readouts: phase 3 topline in the second half of 2028 (company estimate). ^R4

Gray-market vials: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: not FDA-approved; no Drugs@FDA application found (openFDA searched Oct 27, 2026).
Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R5, R6, R7}
Sport: not named on WADA's 2026 list; as a drug not approved anywhere for human use it falls under S0 (non-approved substances) ^R8.

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
ACCESS (phase 2b)	230 adults with obesity or overweight	Oral, daily	Escalated to 45, 90 or 120 mg	36 weeks	Placebo-adjusted weight −8.2% to −11.3%	PMID 42249138
ACCESS open-label extension	ACCESS participants	Oral, daily	Up to 180 mg	72 weeks	Up to −16.2% (company-reported)	^R4

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Rosenstock J, et al. Nat Med. 2026. PMID 42249138
^R2 ClinicalTrials.gov NCT07654361, ACCOMPLISH-1, phase 3 in obesity or overweight, recruiting, 3,600 planned (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT07654361
^R3 ClinicalTrials.gov NCT07654374, ACCOMPLISH-2, phase 3 in obesity or overweight with type 2 diabetes, recruiting, 1,100 planned (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT07654374
^R4 Structure Therapeutics, Structure Therapeutics Reports Positive Clinical Data Across Oral Small Molecule Amylin and GLP-1 Programs for Chronic Weight Management (press release, SEC Form 8-K exhibit 99.1), Sep 8, 2026. https://www.sec.gov/Archives/edgar/data/1888886/000110465926105688/tm2624945d1_ex99-1.htm
^R5 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R6 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R7 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
^R8 WADA. The 2026 Prohibited List, S0 Non-approved substances; full list checked, compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R9 Luna Ceron E, et al. J Brown Hosp Med. 2025. PMID 40191699
^R10 Drugs@FDA, Foundayo (orforglipron), application NDA220934 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=NDA220934
^R11 Pfizer, Pfizer Provides Update on Oral GLP-1 Receptor Agonist Danuglipron, Apr 14, 2025. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-provides-update-oral-glp-1-receptor-agonist
^R12 ClinicalTrials.gov NCT06693843, ACCESS, phase 2b in obesity or overweight, Gasherbrum Bio/Structure, completed, 230 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT06693843
^R13 ClinicalTrials.gov NCT05762471, phase 1b/2a in type 2 diabetes and obesity, Gasherbrum Bio/Structure, completed, 142 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT05762471

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use GSBR-1290 (aleniglipron). This is an investigational drug. It is available only inside registered clinical trials; products sold online under this name are unregulated. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).