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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.

Liraglutide

The older once-daily GLP-1 agonist, with long real-world follow-up and modest effect sizes.

L5Repeated human trialsApproved medicine (jurisdiction-specific) · See jurisdiction details
Full profile

Semaglutide

A GLP-1 receptor agonist with one of the largest clinical trial programmes in modern metabolic medicine.

L5Repeated human trialsApproved medicine (jurisdiction-specific) · FDA (US), European Commission (EU)
Full profile

How far human research has progressed

Liraglutide

Approved, long post-marketing history

Semaglutide

Approved, multiple completed Phase 3 programmes and cardiovascular outcome trials

Claim-specific benefit evidence

A human exposure study or trial registration does not establish that the claimed benefit occurs.

Liraglutide

Not separately assessed; see the full profile.

Semaglutide

Not separately assessed; see the full profile.

Human research context

Liraglutide

Approved, long post-marketing history

Semaglutide

Approved, multiple completed Phase 3 programmes and cardiovascular outcome trials

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.

Liraglutide

Strength of the human efficacy evidence88 of 100 evidence strength

Semaglutide

Strength of the human efficacy evidence95 of 100 evidence strength

Preclinical (animal / lab) evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Liraglutide

Strength of the animal and lab evidence85 of 100 evidence strength

Semaglutide

Strength of the animal and lab evidence90 of 100 evidence strength

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.

Liraglutide

Strength of the human safety evidence92 of 100 evidence strength

Semaglutide

Strength of the human safety evidence88 of 100 evidence strength

Regulatory status (legal position, not proof it works)

Liraglutide

Check jurisdiction-specific details in the profile.

Approved for type 2 diabetes and, in a separate formulation, weight management.

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.

Common claims

Liraglutide

  • · Weight loss
  • · Glycaemic control
  • · Cardiovascular benefit in defined populations

Semaglutide

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

How settled our evidence rating is

Liraglutide

High confidence in ratingL5Repeated human trials

Semaglutide

High confidence in ratingL5Repeated human trials

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.

Liraglutide

Shares the rodent C-cell tumour precautionary labelling of the class. Long human exposure has not established a causal human cancer risk.

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.

What this adds up to, in plain English

Liraglutide

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.

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.

A comparison is not a recommendation

Neither column here is an endorsement, and the compound with the higher numbers is not the “better” or “safer” one — it is simply the one with more or better-quality research behind it. Two compounds can both be poorly evidenced, and better-evidenced says nothing about whether either is a sensible idea for a specific person. That is a conversation for a qualified clinician.