Orforglipron

What it is

Orforglipron is an orally active, small-molecule GLP-1 receptor agonist. It is a nonpeptide, meaning it is not built from amino acids the way peptide drugs are. GLP-1 is a hormone the gut releases after eating, and orforglipron activates the same receptor.

The FDA approved orforglipron as Foundayo on April 1, 2026, for use 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 and at least one weight-related comorbid condition. Orforglipron has also been studied in a large phase 3 program (ATTAIN and ACHIEVE) covering obesity and type 2 diabetes; the approval described here is for weight management.

How it's thought to work

Orforglipron is a small-molecule agonist of the human GLP-1 receptor. According to its FDA label, GLP-1 is a physiological regulator of appetite and caloric intake, GLP-1 receptors are present in brain regions that regulate appetite, and in animal studies orforglipron distributed to and activated neurons in those regions. It acts on the same receptor as injectable GLP-1 medicines, but is an oral tablet.

What the research says

In ATTAIN-1, a phase 3 trial of 3,127 adults with obesity and without diabetes, the mean change in body weight at week 72 was -7.5%, -8.4% and -11.2% in the three orforglipron groups, compared with -2.1% on placebo. The trial reported significantly greater body weight reductions than placebo, with an adverse-event profile consistent with other GLP-1 receptor agonists.

Reported side effects

The Foundayo label lists nausea, constipation, diarrhea, vomiting, dyspepsia, abdominal pain, headache, abdominal distension, fatigue, eructation (belching), gastroesophageal reflux disease, flatulence and hair loss as the most common adverse reactions (reported in at least 5% of patients). In ATTAIN-1, the most common adverse events were gastrointestinal and mostly mild to moderate.

The label carries a boxed warning for the risk of thyroid C-cell tumors that applies to GLP-1 receptor agonist products. It states that orforglipron is not pharmacologically active in rats or mice and did not produce tumors in rodents, and that the human relevance of the rodent findings has not been determined. The label also lists acute pancreatitis among its warnings.

Form

Orforglipron is taken by mouth as tablets, so it is not reconstituted.

Important notes

Orforglipron is an FDA-approved prescription medicine, sold as Foundayo. It is not a peptide but an oral small molecule. Material sold as a research chemical is not a regulated product, and its quality and purity are not independently verified.

Sources

1. FOUNDAYO (orforglipron) tablets, for oral use - Highlights of Prescribing Information. U.S. Food and Drug Administration, 2026. Fda label
2. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment.. Wharton S et al. N Engl J Med, 2025. Human trial

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