Orforglipron (Foundayo)

Structure: Small-molecule, non-peptide GLP-1 receptor agonist (LY3502970, originally OWL833 from Chugai). It binds a pocket in the upper part of the receptor that differs from where GLP-1 and the peptide drugs bind, and it acts as a partial agonist biased towards G-protein signalling over beta-arrestin recruitment. It is inactive at the rodent GLP-1 receptor, which is why its rodent thyroid tumour data mean little either way.

Status:

• United States: FDA approved April 2026 as Foundayo for chronic weight management in adults with obesity, or overweight with a weight-related condition. Approved through the Commissioner's National Priority Voucher pilot.
• United Kingdom: MHRA approved 10 August 2026 for weight management and type 2 diabetes, the first European approval.
• Australia: not approved. Lilly lodged with the TGA around the end of 2025 and it was still awaiting approval in November 2026, when the TGA approved the Wegovy Pill (oral semaglutide 25mg) instead.
• Type 2 diabetes indication filed separately; check current status.

Dosage (US label):

• Tablets: 0.8, 2.5, 5.5, 9, 14.5 and 17.2mg
• Start 0.8mg once daily, then 2.5mg, then 5.5mg, at least 30 days on each. Further steps to 9, 14.5 and 17.2mg at least 30 days apart, based on response and tolerability
• Maximum 17.2mg/day. The trials used 6, 12 and 36mg capsules, which correspond to the 5.5, 9 and 17.2mg tablets. A "36mg" figure in a paper is not a dose to take
• Missed 7 or more days in a row: restart escalation at a lower dose

Administration:

• One tablet a day, swallowed whole, any time, with or without food or water. No fasting window, unlike Rybelsus and the Wegovy Pill
• Bioavailability about 77%; peak levels 4 to 8 hours after a dose

Interactions:

• Metabolised mainly by CYP3A4 and also an OATP1B and P-gp substrate
• Strong CYP3A4 inhibitors (clarithromycin raised exposure 3.5-fold): cap at 9mg. Avoid strong inhibitors that also block OATP1B, such as ritonavir
• Strong inducers (carbamazepine cut exposure 82%): avoid
• Simvastatin: do not exceed 20mg/day
• Oral contraceptives: use a non-oral or backup method for 30 days after starting and after each dose increase
• Do not combine with another GLP-1 agonist

Key Notes:

• Weight loss (ATTAIN-1, 72 weeks): 7.5%, 8.4% and 11.2% at the three doses versus 2.1% on placebo (treatment-regimen estimand); 12.4% on the top dose if everyone stayed on it. In type 2 diabetes (ATTAIN-2) the top dose gave 9.6%.
• Against oral semaglutide (ACHIEVE-3, type 2 diabetes): lowered HbA1c more (1.91 vs 1.47 points at top doses) but caused more GI side effects and roughly twice the discontinuations.
• After injections (ATTAIN-MAINTAIN): people switched from tirzepatide or semaglutide kept about 75 to 79% of their weight loss at one year, versus 38 to 49% on placebo.
• Lean mass: in a 171-person DXA subgroup, 26.9% of weight lost was lean mass, close to tirzepatide and to dieting alone. Resistance training and high protein matter more than the drug choice.
• Heart rate: label pooled rise of 4 to 5 bpm (placebo 0.5); a 2026 network meta-analysis put the 36mg capsule dose at about 9 bpm, the highest of the class. This adds to clenbuterol, T3, trenbolone and stimulants.
• Liver: two earlier oral small-molecule GLP-1 drugs from Pfizer (lotiglipron and danuglipron) were dropped over liver signals, so orforglipron was watched closely. A pooled analysis of 11,220 people in seven phase 3 trials found ALT and AST fell on average and no drug-induced liver injury. The label has no liver-monitoring requirement.
• Pancreas: lipase rose 26 to 31% and pancreatic amylase 16 to 20% on average without symptoms. Do not stop for an isolated lipase rise; do stop for severe upper abdominal pain radiating to the back.
• Kidney: acute kidney injury from dehydration after vomiting or diarrhoea is a label warning.
• Boxed warning: thyroid C-cell tumours (class warning). Contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2.
• Grey-market "research" orforglipron is sold online as powder or capsules. Dose accuracy and purity are unverifiable.
• Monitor: ALT, AST, bilirubin, lipase, creatinine and eGFR (cystatin C if muscular), lipid panel, HbA1c, fasting glucose, morning resting heart rate.

Australian availability, the Wegovy Pill difference, and the bloodwork to run: When will orforglipron be available in Australia?.

References:

• Kawai, T., Sun, B., Yoshino, H., Feng, D., Suzuki, Y., Fukazawa, M., et al. (2020). Structural basis for GLP-1 receptor activation by LY3502970, an orally active nonpeptide agonist. Proceedings of the National Academy of Sciences, 117(47), 29959-29967. DOI: 10.1073/pnas.2014879117
• Wharton, S., Aronne, L. J., Stefanski, A., Alfaris, N. F., Ciudin, A., Yokote, K., et al. (2025). Orforglipron, an oral small-molecule GLP-1 receptor agonist for obesity treatment. New England Journal of Medicine, 393(18), 1796-1806. DOI: 10.1056/NEJMoa2511774
• Rosenstock, J., Yabe, D., Cox, D., Li, J., Denning, M., Wu, W. S., Liu, R., & Zhao, Y. (2026). Efficacy and safety of once-daily oral orforglipron compared with oral semaglutide in adults with type 2 diabetes (ACHIEVE-3). The Lancet, 407(10534), 1147-1160. DOI: 10.1016/S0140-6736(26)00202-3
• Aronne, L. J., Horn, D. B., le Roux, C. W., Chao, A. M., Ho, W., Halpern, B., et al. (2026). Orforglipron for maintenance of body weight reduction: the ATTAIN-MAINTAIN trial. Nature Medicine, 32(7), 2679-2687. DOI: 10.1038/s41591-026-04386-7
• Wharton, S., Stefanski, A., Chen, J., Rao, G., Twum, E. A., & Denning, M. (2026). Hepatic safety of orforglipron in adults with obesity or overweight and/or type 2 diabetes: a pooled analysis of the phase 3 trials. Diabetes, Obesity and Metabolism, 28(9), 8347-8358. DOI: 10.1111/dom.71032
• Zhang, Y., Zhang, C., Gong, X., et al. (2026). Effect of GLP-1 receptor agonists on heart rate in non-diabetic individuals with overweight or obesity: a systematic review and network meta-analysis. European Journal of Medical Research, 31(1), 318. DOI: 10.1186/s40001-026-03933-9