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.
MBX 4291
An investigational long-acting GLP-1 and GIP receptor co-agonist prodrug in Phase 1, with only preliminary small-cohort sponsor-reported data.
Tirzepatide
A dual GIP and GLP-1 receptor agonist with strong Phase 3 weight and glycaemic data.
How far human research has progressed
MBX 4291
Phase 1; preliminary sponsor-reported results from a small number of participantsTirzepatide
Approved, large completed Phase 3 programmeClaim-specific benefit evidence
A human exposure study or trial registration does not establish that the claimed benefit occurs.
MBX 4291
Treatment-attributable weight loss and comparative tolerability are unestablished while the small Phase 1 cohort remains blinded.
Tirzepatide
Not separately assessed; see the full profile.Human research context
MBX 4291
L3 reflects preliminary blinded human weight and pharmacokinetic observations in eight participants, including two assigned placebo; sponsor-reported, not peer reviewed.Tirzepatide
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.
MBX 4291
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.
MBX 4291
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.
MBX 4291
Tirzepatide
Regulatory status (legal position, not proof it works)
MBX 4291
Check jurisdiction-specific details in the profile.
Not approved anywhere. Phase 1 data reported by a sponsor in a small cohort is the earliest kind of human evidence and is not an efficacy finding.
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
MBX 4291
- · Monthly dosing
- · Tirzepatide-like effects with less frequent injections
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
MBX 4291
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.
MBX 4291
Not established. Class-level incretin considerations apply.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
MBX 4291
Treatment-attributable weight loss and comparative tolerability are unestablished while the small Phase 1 cohort remains blinded.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