Orforglipron

Overview

Orforglipron is a synthetic, orally active small-molecule agonist of the human glucagon-like peptide-1 receptor (GLP-1R). It is not a peptide and has no amino-acid sequence. The development names LY3502970, LY-3502970 and OWL833 refer to the same active moiety.

On 1 April 2026, FDA approved Foundayo for long-term weight management in specified adults with obesity or overweight. That is a real regulator approval, but it has boundaries: it is a US prescription-product decision for a defined population and indication. It does not validate unlicensed products, turn every investigated outcome into an approved use or establish EU approval.

Verified identity: active moiety versus calcium product

PubChem records the neutral active moiety as CID 137319706, molecular formula C48H48F2N10O5, molecular weight 883.0 g/mol, CAS 2212020-52-3, UNII 7ZW40D021M and InChIKey USUWIEBBBWHKNI-KHIFEHGGSA-N.

The authorised Foundayo tablets do not contain an unspecified “peptide.” The FDA label identifies orforglipron calcium as the product substance, with formula C48H47F2N10O5·0.5Ca and molecular weight 902.0 g/mol. Tablet strengths are expressed as the amount of orforglipron active moiety; the label also gives the equivalent calcium-salt amount. PubChem keeps the calcium form separately as CID 167713250. These are related forms, not interchangeable identity fields.

PeptideGuide's only citation lead, PMID 33567185, is the STEP 1 semaglutide trial and does not study orforglipron. Its dose, safety-colour and “daily” half-life fields were therefore rejected rather than copied.

Mechanism

The 2020 structural paper (PMID 33177239) describes LY3502970 as a non-peptide GLP-1R partial agonist biased toward G-protein activation over beta-arrestin recruitment. The molecule occupies a distinct pocket in the upper transmembrane bundle and interacts with primate-specific receptor residue Trp33, helping explain why ordinary rodent pharmacology does not directly represent human activity.

The FDA label states that orforglipron binds and activates the human GLP-1 receptor, reduces food intake and delays gastric emptying. Those effects support weight reduction; they do not prove that the medicine treats every condition associated with obesity or reproduces every effect of peptide GLP-1 agonists.

Regulatory status

United States

FDA approved Foundayo in combination with a reduced-calorie diet and increased physical activity to reduce excess body weight and maintain weight reduction long term in adults with obesity, or adults with overweight plus at least one weight-related comorbid condition. Concomitant use with another GLP-1 receptor agonist is not recommended in the label.

European Union

An EMA paediatric-investigation-plan decision exists for orforglipron. A PIP is a development requirement, not a marketing authorisation. A case-insensitive search of the European Commission's Union Register medicinal-products dataset, dated 22 June 2026 and reviewed on 3 August 2026, found no orforglipron or Foundayo match. This supports “no EU central authorisation found”; it is not a claim about every national register or future decision.

Evidence for the approved weight-management indication

The current FDA label rests on two 72-week randomized, double-blind, placebo-controlled trials with lifestyle intervention.

ATTAIN-1 (NCT 05869903) randomized 3,127 adults with obesity or overweight plus a related condition, without type 2 diabetes. The publication reports mean weight changes of -7.5%, -8.4% and -11.2% with the investigational 6, 12 and 36 mg formulations, versus -2.1% with placebo. The 36 mg group had 54.6%, 36.0% and 18.4% of participants reach at least 10%, 15% and 20% weight reduction, respectively, versus 12.9%, 5.9% and 2.8% with placebo. Adverse events caused discontinuation in 5.3-10.3% of orforglipron groups versus 2.7% on placebo.

ATTAIN-2 (NCT 05872620) randomized 1,613 adults with obesity or overweight and type 2 diabetes. At week 72, mean weight changes were -5.1%, -7.0% and -9.6% with 6, 12 and 36 mg versus -2.5% with placebo. Adverse-event discontinuation was 6.1-9.9% versus 4.1%. The study supports weight management in people who also have diabetes; it does not by itself create a labelled diabetes-treatment indication.

The FDA label presents these investigational formulations as equivalent commercial Foundayo strengths of 5.5, 9 and 17.2 mg. Mixing the trial and commercial numbers without this formulation boundary can create an apparent contradiction and must be avoided.

Diabetes evidence remains a separate line

In ACHIEVE-1 (PMID 40544435), 559 adults with early type 2 diabetes were randomized for 40 weeks. HbA1c fell more with each orforglipron arm than with placebo, and body weight changed by -4.5%, -5.8% and -7.6% versus -1.7%. Permanent discontinuation for adverse events was 4.4-7.8% versus 1.4%; no severe hypoglycaemia occurred.

In the open-label ACHIEVE-3 trial (PMID 41765029), orforglipron met non-inferiority and prespecified superiority comparisons against oral semaglutide for HbA1c change at 52 weeks. The trade-off matters: gastrointestinal events, adverse-event discontinuations and mean pulse increases were higher with orforglipron. Open-label head-to-head results do not erase those harms or expand the FDA indication.

The 2026 ACHIEVE-5 trial (PMID 42251769) found better HbA1c and weight outcomes when orforglipron was added to titrated insulin glargine versus placebo, without a detected increase in clinically significant hypoglycaemia. It is additional trial evidence, not a substitute for a regulator's indication.

Safety and interaction boundaries

The FDA label carries a boxed thyroid C-cell-tumour warning with unusual species context: orforglipron is not pharmacologically active in rats or mice and did not produce tumours in rodents, while the human relevance of GLP-1- dependent rodent tumours observed with active class members remains unknown. Foundayo is contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2, and with known serious hypersensitivity.

Important label warnings include acute pancreatitis, sometimes-severe gastrointestinal reactions, acute kidney injury from volume depletion, hypoglycaemia with insulin or an insulin secretagogue, serious hypersensitivity, diabetic-retinopathy complications, acute gallbladder disease and pulmonary aspiration during anaesthesia or deep sedation. It is not recommended in severe gastroparesis or severe hepatic impairment.

The most common labelled adverse reactions, each reported in at least 5% of treated participants, include nausea, constipation, diarrhoea, vomiting, dyspepsia, abdominal pain, headache, abdominal distension, fatigue, eructation, gastro-oesophageal reflux, flatulence and hair loss. In the pooled weight- management trials, permanent discontinuation due to adverse reactions occurred in 6%, 9% and 10% at the three commercial maintenance strengths versus 3% on placebo; most treatment-related discontinuations were gastrointestinal.

Pregnancy may involve fetal harm. The label advises stopping when pregnancy is recognized and adds a specific oral-contraceptive boundary for 30 days after starting and after each dose escalation. Strong CYP3A4 inhibitors and inducers, OATP1B inhibition, simvastatin exposure and delayed gastric emptying create clinically relevant interaction rules that require the current label and professional review.

Pharmacokinetics and administration boundary

The FDA label reports peak concentration 4-8 hours after a dose, oral bioavailability of 77% after the studied 0.8 mg dose, protein binding above 99%, primary CYP3A4 metabolism and an elimination half-life of approximately 29-49 hours. No clinically relevant food effect was found, and the approved tablet may be taken with or without food.

These values describe a regulator-reviewed product and studied formulations. They do not authenticate grey-market material or turn the source database's unverified 12-24 mg and 45 mg figures into personal dosing guidance.

Current research programme

An exact ClinicalTrials.gov API query for orforglipron OR LY3502970 on 3 August 2026 returned 51 records: 32 completed, 8 active but not recruiting, 7 recruiting and 4 not yet recruiting. Active questions include cardiovascular outcomes, adolescents, obstructive sleep apnoea, hypertension, osteoarthritis and other obesity-related conditions. Registry status shows that research is occurring; it does not show efficacy or approval.

The 2026 ATTAIN-MAINTAIN phase 3b trial randomized participants after prior tirzepatide or semaglutide treatment and found more of the prior weight reduction was maintained with orforglipron than placebo at one year. Its own limitations include no continued-injectable comparator and one-year duration. It should not be rewritten as proof that switching is best for every patient.

Russian-language and Russia-origin evidence pass

Russian searches included орфорглипрон, орфорглипрона, LY3502970, орфорглипрон клиническое исследование, орфорглипрон ожирение, орфорглипрон сахарный диабет and named Russian medicine-register surfaces. No Russian-origin primary human trial or Russian marketing authorisation was located in the accessible indexed results.

The Russian Academy of Sciences centre's May 2026 drug-development digest correctly reports the FDA approval and summarizes ATTAIN-1 and ATTAIN-2, but it also calls orforglipron a revolutionary option for cardiovascular-disease prevention. The FDA label does not grant a prevention indication, and the dedicated cardiovascular-outcomes study remains in the active registry. That stronger Russian-language wording is therefore not adopted.

Several Russian-language “trial registry” pages were automatic translations of ClinicalTrials.gov records. They are useful for accessibility but are not independent Russian studies. This bounded result avoids English-only searching without manufacturing a Russian evidence lane that was not found.

Sport and WADA

The indexed official 2026 WADA Prohibited List reviewed for this article did not specifically name orforglipron, Foundayo or GLP-1 receptor agonists. That is a bounded named-text result only: no S0 or other WADA class is inferred, and absence of a named match is not permission. Athletes remain responsible for the current list, their governing rules and the actual contents of any product.

Evidence bottom line

Orforglipron has moved beyond an investigational database entry: it is a defined non-peptide small molecule and, as Foundayo, a US-approved prescription medicine for a specific weight-management indication. Its evidence base now includes large phase 3 trials, while gastrointestinal tolerability, interaction rules, pregnancy and thyroid warnings remain central.

The most important 2026 reading discipline is to keep four things separate: the 883.0 g/mol active moiety from the 902.0 g/mol calcium product form; trial formulation doses from commercial strengths; FDA-approved weight management from investigational diabetes and cardiometabolic uses; and licensed tablets from unverified internet products.