Semaglutide

How far human research has progressed: Approved, multiple completed Phase 3 programmes and cardiovascular outcome trials

Approved products are subcutaneous injections (Ozempic, Wegovy). There are now two distinct oral products and they are not interchangeable: Rybelsus is authorised for type 2 diabetes, while the oral Wegovy 25 mg tablet is authorised for chronic weight management. Different products, different indications, different trial programmes — the same molecule is not the same medicine, and evidence from one formulation does not automatically transfer to another.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

A long-acting synthetic analogue of GLP-1, a gut hormone released after eating. It slows gastric emptying, increases glucose-dependent insulin release and acts on appetite circuits in the brain.

• Substantial and sustained weight loss
• Improved blood glucose control in type 2 diabetes
• Reduced cardiovascular events in higher-risk groups
• Reduces 'food noise'

This is one of the rare cases where the marketing and the evidence are roughly in the same postcode. Large randomised trials show clinically meaningful weight loss and glycaemic improvement, with outcome data in specific higher-risk populations. Effects depend on continued use; discontinuation is generally followed by partial weight regain. The trial programme is now extending into younger children: Novo Nordisk announced STEP Young Phase 3 topline results on 7 September 2026 in children aged 6 to under 12, which are sponsor-reported and not yet peer-reviewed full data.

• Multiple large randomised, placebo-controlled Phase 3 trials in type 2 diabetes and obesity.
• Cardiovascular outcome trials in defined higher-risk populations.
• Long-term extension data on weight maintenance and regain after stopping.
• Exploratory post hoc analysis of a 32-week randomised, double-blind, placebo-controlled Phase 2b trial in adults with HIV-associated lipohypertrophy found lower estimates across several DNA-methylation aging clocks versus placebo, including a 0.09 lower DunedinPACE value. Epigenetic aging was not a prespecified endpoint and this does not establish rejuvenation or longer human lifespan.
• A separate 24-week SLIM LIVER pilot analysis in people with HIV and metabolic dysfunction-associated steatotic liver disease reported changes in epigenetic-aging measures associated with metabolic response; the pilot design does not establish causality or longevity benefit.
• Sponsor-reported topline (Novo Nordisk, 7 September 2026): the STEP Young Phase 3 trial in children aged 6 to under 12 with obesity met its primary endpoint. Under the trial-product estimand, 40.4% of semaglutide-treated children were below the obesity BMI threshold after 68 weeks versus 0% on placebo, with both groups receiving lifestyle modification. Novo reported overall safety and tolerability consistent with previous adult and adolescent semaglutide experience; that is a sponsor topline statement, not a completed peer-reviewed safety analysis in this age group.

• Extensive rodent work on appetite circuits, gastric emptying and islet function.
• Rodent thyroid C-cell tumour findings that drive a labelled contraindication for people with a personal or family history of medullary thyroid carcinoma or MEN2.
• A 2026 Nature study starting semaglutide at 20 months of age in female C57BL/6 mice reported improved physiological function, attenuation of several hallmarks of aging and extended lifespan with continued treatment. This is preclinical evidence and does not demonstrate human lifespan extension.

Animal and cell findings are Level 1–2 evidence.

• GLP-1 receptor agonism in pancreatic beta cells increases glucose-dependent insulin secretion.
• Central GLP-1 receptor signalling in hypothalamic and brainstem circuits reduces appetite and reward-driven eating.
• Delayed gastric emptying increases fullness after meals.

Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.

Named regulators: FDA (US), European Commission (EU)

Authorised product and indication: Approval varies by product and indication: Ozempic, Rybelsus and Wegovy have distinct authorisations. See the regulatory note for formulation-specific details.

Approved in multiple regions for type 2 diabetes and, in separate formulations, for weight management. In March 2024 the FDA approved Wegovy to reduce the risk of cardiovascular death, heart attack and stroke in adults with established cardiovascular disease and overweight or obesity, and in August 2025 granted accelerated approval for Wegovy in adults with noncirrhotic MASH with moderate-to-advanced (F2-F3) fibrosis. On 22 December 2025 the FDA approved a once-daily oral semaglutide 25 mg Wegovy tablet for chronic weight management, launched in January 2026; the European Commission approved the Wegovy tablet and a 7.2 mg injection/pen in July 2026. Every approval is product- and indication-specific. On a US legal point, the Fifth Circuit upheld FDA's semaglutide shortage-list determination in an opinion revised on 1 September 2026. That reinforces the shortage delisting and the end of shortage-based routine copying of the approved products; it does not make every form of individually tailored compounding categorically unlawful, as narrow statutory exceptions can still apply. This is legal and regulatory evidence, not efficacy or safety evidence.

• 2024-03-08 · United States

  FDA approved Wegovy to reduce the risk of cardiovascular death, heart attack and stroke in adults with established cardiovascular disease and overweight or obesity.

• 2025-08 · United States

  FDA granted accelerated approval to Wegovy for adults with noncirrhotic MASH with moderate-to-advanced liver fibrosis (F2-F3).

• Long-term registry data resolving the thyroid signal in humans either way.
• Head-to-head outcome trials against newer multi-receptor agonists.
• Prospectively powered human geroscience trials with prespecified aging endpoints, multiple-testing control, longer follow-up and clinical or functional outcomes rather than biomarker changes alone.

• Regulatory / labelFDA press release — Wegovy approved to reduce risk of serious heart problems in adults with obesity or overweight (8 March 2024)
• Regulatory / labelWegovy prescribing information (FDA label, incl. MASH accelerated approval)
• Sponsor / officialNovo Nordisk — FDA approval of once-daily oral semaglutide 25 mg (Wegovy tablet) for chronic weight management, 22 December 2025
• Sponsor / officialNovo Nordisk — European Commission approval of the Wegovy tablet and 7.2 mg injection (July 2026)
• Sponsor / officialNovo Nordisk — STEP Young Phase 3 topline results in children aged 6 to under 12 (7 September 2026, sponsor-reported)
• Peer-reviewedCorley et al. — Semaglutide slows epigenetic aging in a randomized trial of HIV-associated lipohypertrophy (Nature Communications, 2026)
• Peer-reviewedCorley et al. — Pilot study of epigenetic aging and treatment response to semaglutide in the SLIM LIVER study (npj Aging, 2026)
• Peer-reviewedFeng et al. — Late-life semaglutide treatment slows ageing and extends lifespan in female mice (Nature, 2026)
• Regulatory / labelFDA press announcement — proposal to exclude semaglutide, tirzepatide and liraglutide from the 503B bulks list (30 April 2026)
• Regulatory / labelFDA — FDA's concerns with unapproved GLP-1 drugs used for weight loss
• Regulatory / labelUS Court of Appeals for the Fifth Circuit — Outsourcing Facilities Association v. FDA (semaglutide), No. 25-10758, opinion revised 1 September 2026

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

These entries record changes to our assessment of the published evidence — not changes to the compound itself.

1. 2026-10-01

   Added 2026 randomized human epigenetic-aging evidence, a smaller human pilot analysis, and late-life mouse lifespan evidence, with explicit separation between biomarker changes, mechanistic plausibility and unproven human longevity claims.

   Change 1 of 3

   L5Repeated human trials

   No overall compound-rating change. Semaglutide remains L5 because of its established approved clinical evidence base. The aging evidence is claim-specific: randomized human evidence currently supports changes in DNA-methylation aging biomarkers in a specific population, while lifespan extension has only been demonstrated in female mice. Human rejuvenation or lifespan extension is not established. Reviewed 1 October 2026.

2. 2026-09-09

   Novo Nordisk announced STEP Young Phase 3 topline results on 7 September 2026 in children aged 6 to under 12 years with obesity. The trial met its primary endpoint: under the trial-product estimand, 40.4% of semaglutide-treated children were below the obesity BMI threshold after 68 weeks versus 0% on placebo, with both groups receiving lifestyle modification. Novo reported overall safety and tolerability consistent with previous adult and adolescent experience.

   Change 2 of 3

   L5Repeated human trials

   No rating moved. Semaglutide is already at the highest evidence level, and these are sponsor-reported topline results rather than peer-reviewed full data — the detailed efficacy and safety analyses in this age group have not yet been published or reviewed by a regulator for a paediatric weight-management indication in under-12s. The sponsor's tolerability statement is recorded as reported and not upgraded into a stronger safety conclusion. Reviewed 9 September 2026.

3. 2026-09-06

   Formulation and regulatory update: FDA approved a once-daily oral semaglutide 25 mg Wegovy tablet for chronic weight management on 22 December 2025, launched January 2026; the European Commission approved the Wegovy tablet and the 7.2 mg injection in July 2026.

   Change 3 of 3

   L5Repeated human trials

   The evidence level did not change; the product landscape did. There are now two distinct oral semaglutide products with different authorised uses — Rybelsus for type 2 diabetes and the oral Wegovy tablet for weight management. They are not interchangeable.