Aleniglipron: The New Oral GLP-1 Pill With 12.1% Weight Loss at 36 Weeks

The race to make weight-loss drugs you swallow instead of inject has a new front-runner. In June 2026, Nature Medicine published the Phase 2b ACCESS trial of aleniglipron (GSBR-1290), Structure Therapeutics’ once-daily oral GLP-1 pill — with up to 12.1% average weight loss at 36 weeks, no drug-induced liver injury, and no deaths, the highest weight loss reported for an oral GLP-1 to date.

What is aleniglipron (GSBR-1290)?

Aleniglipron is an investigational, once-daily oral GLP-1 receptor agonist for obesity and overweight. GLP-1 receptor agonists mimic a gut hormone that slows digestion, curbs appetite, and improves blood-sugar control — the mechanism behind Ozempic, Wegovy, and Zepbound. What sets aleniglipron apart is chemistry: most GLP-1 drugs are peptides that stomach acid degrades (hence injections, or absorption enhancers like the Wegovy pill’s). Aleniglipron is a non-peptide small molecule.

A small-molecule GLP-1, explained

No injection, no refrigeration (easier to produce at scale), no food restrictions, and a lower manufacturing cost than peptide drugs — advantages for future pricing and access.

What makes aleniglipron different from Wegovy and Ozempic?

Wegovy and Ozempic are both semaglutide — a peptide. Ozempic is injected; the Wegovy pill (oral semaglutide 25 mg) requires an empty stomach, ≤4 oz of water, and a 30-minute wait before eating. Aleniglipron is a different molecule entirely, designed for once-daily dosing with none of those constraints.

The ACCESS Phase 2b trial: design and results

The ACCESS trial (Nature Medicine, June 5, 2026) was a randomized, double-blind, placebo-controlled, dose-ranging study with a 36-week treatment period:

• 406 adults screened → 230 randomized across 38 U.S. sites (October 28, 2024 – February 7, 2025)
• Adults 18–80 with obesity (BMI ≥30) or overweight (BMI ≥27 plus ≥1 weight-related comorbidity); diabetes excluded
• Randomization 3:4:4 across 45/90/120 mg cohorts, then 3:1 drug:placebo; 5 mg start, titrated every 4 weeks
• Baseline: mean BMI 39.5 kg/m², weight 114.8 kg, age 49.8; 54% female

How much weight did aleniglipron patients lose?

Every dose hit the primary endpoint (weight change versus placebo) at week 36 — all placebo-adjusted differences P < 0.0001:

Dose	Weight change at week 36 (LS mean)	Placebo-adjusted
45 mg	−9.0%	−8.2%
90 mg	−10.7%	−9.8%
120 mg	−12.1%	−11.3%
Placebo	−0.8%	—

At 120 mg, 86% of patients lost at least 5% of body weight (vs 23% on placebo), 70% lost at least 10%, and 38% lost at least 15%. Weight had not plateaued when the blinded period ended. One caveat: 12.1% is the group’s least-squares mean, not an individual maximum — results varied person to person.

How is aleniglipron dosed?

Once daily, from a 5 mg start escalated every 4 weeks to 45, 90, or 120 mg — designed to limit GI side effects. ACCESS II explored doses up to 240 mg.

Aleniglipron side effects and safety

What are the most common side effects?

Gastrointestinal effects — the GLP-1 class signature — dominated: nausea (up to 71.1%), vomiting (up to 44.6%), diarrhea, and constipation, generally mild to moderate and decreasing over time.

Did anyone stop treatment?

Yes — 10.4% of aleniglipron-treated participants discontinued, mostly GI effects early in titration, with no dose-response in dropout rates. Serious adverse events: 2.2% (45 mg), 0% (90 mg), 6.3% (120 mg), versus 5.4% on placebo. No deaths occurred.

Is aleniglipron safe for the liver?

The trial reported no drug-induced liver injury; the 8 cases ≥3× ULN and 1 case ≥5× ULN resolved without stopping the drug. Blood pressure, HbA1c, hsCRP (an inflammation marker), and waist circumference improved, with no QTc (heart rhythm) signal.

Beyond 36 weeks: durability and the ACCESS II trial

The 36-week number isn’t the ceiling: a prespecified interim analysis of the open-label extension (median 20 more weeks; week 56) showed total mean weight loss of 13.3% (45 mg), 16.2% (90 mg), and 15.3% (120 mg) — continued loss, no plateau (interim data, not final).

Two details stand out:

• Slower titration works. Placebo patients crossing over at a 2.5 mg start lost 6.4% by week 56 with no vomiting events and no side-effect-related discontinuations — the rationale for the planned Phase 3 starting dose.
• ACCESS II confirms no plateau. At 44 weeks (doses to 240 mg; topline March 16, 2026), placebo-adjusted weight loss reached 16.3% at 180 mg and 16.0% at 240 mg (P < 0.0001).

Is aleniglipron FDA approved?

No — aleniglipron is not FDA approved. It is investigational. Structure Therapeutics completed its End-of-Phase-2 meeting with the FDA, and the Phase 3 program (ACCOMPLISH-1, NCT07654361) is already recruiting (since July 13, 2026), on track to initiate in Q3 2026 at a 2.5 mg starting dose.

Setting the record straight on the broader timeline: no oral GLP-1 was FDA-approved in August 2026. The real milestones:

• Wegovy pill (oral semaglutide 25 mg, Novo Nordisk) — first oral GLP-1 approved for weight management (FDA, December 22, 2025; EU July 15, 2026)
• Foundayo (orfoglipron, Eli Lilly) — second oral GLP-1 for obesity (FDA, April 1, 2026; UK August 10, 2026 — first in Europe)
• Rybelsus (oral semaglutide) — first oral GLP-1 ever (2019), but type 2 diabetes only

When will aleniglipron be available?

Not soon — Phase 3 takes years, and an FDA submission follows. Today aleniglipron is available only through clinical trials; anything sold online as “aleniglipron” is unapproved and unregulated. Follow the FDA peptide timeline tracker and our coverage of the FDA’s GLP-1 compounding policy.

Oral GLP-1 comparison: aleniglipron vs Wegovy pill vs Foundayo

Drug (molecule)	Company	Regulatory status	Dosing	Key efficacy result	Food rules
Wegovy pill (oral semaglutide 25 mg)	Novo Nordisk	FDA-approved Dec 22, 2025 (first oral GLP-1 for weight)	Once daily; 1.5→4→9→25 mg	OASIS 4 (64 wk): 16.6% when adhered to; ~14% average	Empty stomach, ≤4 oz water, 30-min wait
Foundayo (orfoglipron)	Eli Lilly	FDA-approved Apr 1, 2026; UK Aug 10, 2026	Once daily; 0.7–17.2 mg	ATTAIN-1 (72 wk): 12.4% (27.3 lb) on-treatment	Anytime — no food or water restrictions
Rybelsus (oral semaglutide)	Novo Nordisk	FDA-approved 2019 — first oral GLP-1, T2D only	Once daily; 7/14 mg	Type 2 diabetes indication (not weight loss)	—
Aleniglipron (GSBR-1290)	Structure Therapeutics	Investigational — Phase 3 recruiting (Q3 2026)	Once daily; 45/90/120 mg (to 240 mg studied)	ACCESS (36 wk): 12.1%; OLE up to 16.2% @ wk 56; ACCESS II 16.3% @ 44 wk	With or without food
Elecoglipron	AstraZeneca	Investigational — Phase IIb (Lancet, Jun 2026); Phase III planned	Once daily; 75 mg (VISTA)	VISTA (36 wk): 11.8%	Once-daily oral tablet

Earlier-stage pipeline: Roche’s CT-996, Ascletis’ ASC30, and Viking’s oral VK2735. For the full class comparison — every oral GLP-1 in or near the clinic, with dosing, food rules, and regulatory status side by side — see our oral GLP-1 comparison page.

Wegovy pill vs Foundayo: the two approved pills

For what’s available today, the choice is the Wegovy pill or Foundayo. The Wegovy pill posted higher trial numbers (16.6% mean weight loss when adhered to in OASIS 4; ~14% average) but carries the strictest administration rules. Foundayo delivered 12.4% on-treatment in ATTAIN-1 and can be taken anytime, with or without food. Both are once-daily, refrigeration-free pills.

Aleniglipron vs injectable GLP-1s

Injectable GLP-1s remain the efficacy benchmark, routinely reaching 15–20% weight loss in long-term trials. Aleniglipron’s 16.3% placebo-adjusted result at 44 weeks narrows that gap — though it’s one trial, and cross-trial comparisons aren’t head-to-head. The trade-off: an injection with longer, proven data versus a pill with greater convenience and a shorter evidence base. For what GLP-1 treatment does beyond the scale, see our explainer on GLP-1s and visceral belly fat.

FAQ

Is aleniglipron FDA approved?

No. Aleniglipron (GSBR-1290) is investigational and not yet submitted to the FDA. Its Phase 3 program (ACCOMPLISH-1) is recruiting, targeting a Q3 2026 start. The only FDA-approved oral GLP-1s for weight management are the Wegovy pill (Dec 22, 2025) and Foundayo (Apr 1, 2026).

How much weight can you lose with a GLP-1 pill?

In trials, oral GLP-1s produced average losses of roughly 12–16%: aleniglipron 12.1% at 36 weeks, the Wegovy pill ~14% on average (16.6% in the adherent OASIS 4 analysis), Foundayo 12.4% on-treatment (ATTAIN-1). These are group averages — individual results vary.

What is the strongest oral GLP-1?

By reported data, aleniglipron’s ACCESS II result — 16.3% placebo-adjusted weight loss at 44 weeks on 180 mg — is the highest efficacy signal for any oral GLP-1 to date. Among approved pills, the Wegovy pill’s 16.6% (adherent analysis) is the top figure. Cross-trial comparisons should be read with caution.

Can you take a GLP-1 pill with food?

It depends on the drug. Aleniglipron and Foundayo can be taken with or without food. The Wegovy pill cannot: empty stomach, ≤4 oz of water, and a 30-minute wait before eating or drinking.

What are the side effects of oral GLP-1 pills?

Gastrointestinal effects are most common: nausea, vomiting, diarrhea, constipation, and decreased appetite. In ACCESS, nausea reached 71.1% and vomiting 44.6% in some dose groups — mostly mild to moderate, decreasing over time. About 10.4% of aleniglipron patients stopped, mostly due to GI effects early in titration.

How does aleniglipron compare to Wegovy pill and Foundayo?

Aleniglipron is not yet approved; the Wegovy pill and Foundayo are FDA-approved. On trial data, aleniglipron’s efficacy is at or above the approved pills, and like Foundayo it has no food restrictions. The deciding factor is timing: aleniglipron won’t reach patients until Phase 3 completes.

Bottom line

Aleniglipron is the strongest oral GLP-1 efficacy signal to date — 12.1% average weight loss at 36 weeks, no plateau, no liver signal, and 16%+ placebo-adjusted at 44 weeks. But it is an investigational drug: not FDA approved, not available outside clinical trials, and anything sold online under that name is unapproved and unregulated. Watch the Phase 3 readouts, and for the compounding-regulatory backdrop see our analysis of the compounded GLP-1 ban push.

Stay ahead of the GLP-1 and peptide landscape — subscribe to the PeptidesBeat newsletter for weekly research and regulatory digests, and follow the FDA peptide timeline tracker as the aleniglipron Phase 3 program gets underway.

PeptidesBeat is an independent editorial publication covering peptide research, policy, and industry developments. We do not sell peptides, recommend dosing, or provide medical advice. All content is informational. Aleniglipron is an investigational drug not approved by the FDA; it is not available for clinical use outside registered trials. Consult a licensed healthcare provider for any medical question.