Comparison Centre
Two compounds, the same questions, no cherry-picking
Marketing compares compounds on whichever measure flatters them. This compares them on the same fields every time — including the awkward ones like how much human safety data exists. Every score here rates the evidence, not the compound: a higher number means stronger or more mature research, not that something is safer or works better.
Sharing keeps the two compounds you picked.
How to read these scores
Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.
- Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
- Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
- Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
- Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
- Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.
None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.
Semaglutide
A GLP-1 receptor agonist with one of the largest clinical trial programmes in modern metabolic medicine.
Tirzepatide
A dual GIP and GLP-1 receptor agonist with strong Phase 3 weight and glycaemic data.
How far human research has progressed
Semaglutide
Approved, multiple completed Phase 3 programmes and cardiovascular outcome trialsTirzepatide
Approved, large completed Phase 3 programmeClaim-specific benefit evidence
A human exposure study or trial registration does not establish that the claimed benefit occurs.
Semaglutide
Not separately assessed; see the full profile.Tirzepatide
Not separately assessed; see the full profile.Human research context
Semaglutide
Approved, multiple completed Phase 3 programmes and cardiovascular outcome trialsTirzepatide
Approved, large completed Phase 3 programmeHuman efficacy evidence strength
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Semaglutide
Tirzepatide
Preclinical (animal / lab) evidence strength
Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
Semaglutide
Tirzepatide
Human safety evidence strength
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
Semaglutide
Tirzepatide
Regulatory status (legal position, not proof it works)
Semaglutide
Named regulators: FDA (US), European Commission (EU)
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.
Tirzepatide
Named regulators: FDA (US)
Approved in multiple regions for type 2 diabetes (Mounjaro) and, under a separate brand (Zepbound), for chronic weight management. In December 2024 the FDA approved Zepbound as the first medication for obstructive sleep apnoea in adults with obesity. Additional indications vary by regulator. On 27 August 2026 the US Court of Appeals for the Fifth Circuit upheld FDA's determination that tirzepatide is no longer in shortage, rejecting a challenge brought by compounding interests. The practical effect is to reinforce the shortage delisting and the end of shortage-based routine copying of the approved product; it does not mean every form of individually tailored compounding is categorically unlawful, since narrow statutory exceptions can still apply. This is legal and regulatory evidence about US supply routes, not efficacy or safety evidence about the molecule.
Common claims
Semaglutide
- · Substantial and sustained weight loss
- · Improved blood glucose control in type 2 diabetes
- · Reduced cardiovascular events in higher-risk groups
- · Reduces 'food noise'
Tirzepatide
- · Greater average weight loss than single-agonist GLP-1s
- · Strong glycaemic control
- · Improves obstructive sleep apnoea severity in people with obesity
How settled our evidence rating is
Semaglutide
Tirzepatide
Cancer-related questions raised by the biology
These are theoretical or monitored questions raised by how a compound works. They are not evidence that it causes cancer.
Semaglutide
Rodent studies showed thyroid C-cell tumours, which is why labelling carries a contraindication in people with specific thyroid cancer syndromes. That is a species-specific preclinical signal plus a precautionary label, not a demonstrated human cancer risk. Pharmacovigilance continues.Tirzepatide
Carries the same rodent-derived precautionary thyroid labelling as other incretin drugs in several regions. No demonstrated human cancer causation; long-term surveillance is ongoing.What this adds up to, in plain English
Semaglutide
Repeated large human trials support specific uses in the groups studied. That is strong evidence something works there — not proof it suits everyone or is free of risk.Tirzepatide
Repeated large human trials support specific uses in the groups studied. That is strong evidence something works there — not proof it suits everyone or is free of risk.A comparison is not a recommendation