GSBR-1290 · Evidence-based safety and harm-reduction overview.
| Also known as | GSBR-1290 |
| Category | GLP-1 / Metabolic |
| Developer | Structure Therapeutics Inc. |
| Development code | GSBR-1290 |
| Drug class | Non-peptide small-molecule GLP-1 receptor agonist (allosteric/bitopic transmembrane binder) |
| Development stage (mid-2026) | Phase 2b complete; Phase 3 initiation anticipated 2026; no FDA approval |
| Phase 2b weight loss (36 wk, placebo-adjusted) | 8.2% (45 mg), 9.8% (90 mg), 11.3% (120 mg) |
| Administration route | Once-daily oral; no food restrictions required at dosing |
| US legal status | Investigational drug (IND status only) in the United States. Not approved by the FDA for any indication. No marketed formulation exists. Not legally available for human use outside of approved clinical trials. Not a dietary supplement. |
Aleniglipron (development code GSBR-1290) is an investigational, once-daily oral small-molecule GLP-1 receptor agonist developed by Structure Therapeutics Inc. Unlike the peptide-based GLP-1 agonists currently approved (e.g., semaglutide, liraglutide), aleniglipron is a non-peptide compound that achieves oral bioavailability without requiring food restrictions at dosing. It has completed Phase 2b development and Phase 3 initiation was anticipated in 2026; it has no FDA approval and remains investigational only.
Aleniglipron is a non-peptide, allosteric or bitopic GLP-1 receptor agonist that binds the transmembrane pocket of the GLP-1 receptor. This binding site is distinct from the extracellular domain used by peptide-based GLP-1 agonists such as semaglutide. Activation of the GLP-1 receptor by aleniglipron stimulates insulin secretion in a glucose-dependent manner, suppresses glucagon release, slows gastric emptying, and reduces appetite via central and peripheral pathways, leading to reduced caloric intake and body weight. The small-molecule scaffold enables oral administration and avoids the degradation that limits peptide agonists to injection or specialized oral formulations with strict prandial requirements.
Aleniglipron was developed by Structure Therapeutics Inc. as part of a broader effort to produce orally bioavailable small-molecule GLP-1 receptor agonists - a field that gained substantial attention following the commercial success of injectable semaglutide and once-daily oral semaglutide (Rybelsus), which requires strict fasting administration. Structure Therapeutics advanced GSBR-1290 through preclinical and early clinical stages, initiating the Phase 2b ACCESS trial and subsequently the extended ACCESS II program. Phase 2b topline results were reported in 2025 and 44-week data were published in Nature Medicine in 2026, positioning aleniglipron as one of the more clinically advanced candidates in the small-molecule oral GLP-1 agonist pipeline alongside orforglipron (Eli Lilly) and danuglipron (Pfizer, which was deprioritized due to tolerability).
As of mid-2026, aleniglipron has completed Phase 2b clinical evaluation. The Phase 2b ACCESS trial (NCT06693843) was a randomized, double-blind, placebo-controlled study enrolling approximately 230 adults with obesity or overweight plus at least one weight-related comorbidity. At 36 weeks, placebo-adjusted weight loss was 8.2% at 45 mg, 9.8% at 90 mg, and 11.3% at 120 mg daily; the primary endpoint was met across all three dose arms. Secondary endpoints including systolic and diastolic blood pressure reduction, high-sensitivity CRP lowering, waist circumference reduction, and HbA1c improvement were also reported. Extended 44-week follow-up data from the Phase 2 ACCESS II trial (NCT06703021) were published in Nature Medicine in 2026 (PubMed PMID 42249138). A body composition substudy (NCT07169942) was also conducted. Phase 3 protocol discussions with the FDA were anticipated in 2026. Long-term efficacy and safety data from Phase 3 are not yet available, and no regulatory approval has been granted anywhere in the world.
Phase 2b clinical trial doses tested were 45 mg, 90 mg, and 120 mg once daily without food restrictions. These ranges are drawn from published trial protocols and results and are provided for informational reference only - they describe what was studied in controlled clinical settings under medical supervision. They are not a dosing protocol and should not be used to guide self-administration. Aleniglipron is not approved for any use outside of clinical trials. Consult a licensed clinician for any questions about GLP-1 therapies or weight management pharmacotherapy.
This is general research/context information, not medical advice or a recommended protocol.
No human data exist on combination with other weight-loss agents, GLP-1 agonists, GIP/GLP-1 co-agonists (e.g., tirzepatide), or other metabolic agents. Phase 2b trials studied aleniglipron as monotherapy. Combination use is untested and outside the scope of published evidence.
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Get tested with Ulta Lab Tests →Semaglutide and tirzepatide are peptide-based GLP-1 receptor agonists administered by subcutaneous injection (or, for semaglutide, via a specialized oral formulation requiring strict fasting). Aleniglipron is a non-peptide small molecule that binds a different site on the GLP-1 receptor (the transmembrane pocket rather than the extracellular domain) and can be taken orally once daily without food restrictions. It remains investigational and has not been approved; direct head-to-head comparative efficacy data with approved agents do not exist.
No. As of mid-2026, aleniglipron holds investigational drug status in the United States. It has completed Phase 2b trials and Phase 3 is anticipated, but no new drug application has been submitted or approved. It is not legally available for use outside of clinical trials.
In the Phase 2b ACCESS trial (approximately 230 participants, randomized placebo-controlled, 36 weeks), placebo-adjusted weight loss was 8.2% at 45 mg, 9.8% at 90 mg, and 11.3% at 120 mg daily. These figures are from a Phase 2 trial population and may not predict outcomes in broader populations; Phase 3 data are pending.
No dosing recommendation can be provided. Aleniglipron is an unapproved investigational drug. Any questions about weight management pharmacotherapy should be directed to a licensed physician or endocrinologist.
The most common adverse events in Phase 2b were gastrointestinal - nausea, vomiting, and diarrhea - graded mild to moderate in severity and decreasing in frequency over time. The overall discontinuation rate due to adverse events was approximately 10.4%, concentrated in the dose titration period. No serious safety signals or off-target events were identified in Phase 2 data, though long-term safety data from Phase 3 are not yet available.
No. Aleniglipron is an investigational drug with no approved formulation available outside clinical trials. Any product sold under this name by third-party suppliers cannot be verified for purity, identity, or safety, and its acquisition and use would carry substantial unknown risks. Participation in ongoing registered clinical trials is the only legitimate route to access.
Medical & legal disclaimer. This site is for informational and harm-reduction purposes only. It is not medical advice and is not a substitute for a licensed healthcare professional. The compounds discussed are largely not approved by the FDA for human use and many are sold strictly as research chemicals 'not for human consumption.' Nothing here is an endorsement to purchase, possess, or use any substance. Laws vary by jurisdiction. Always consult a qualified physician and follow the law where you live.
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