GLP-1s & incretins · Metabolic & endocrine
An investigational long-acting GLP-1 and GIP receptor co-agonist prodrug in Phase 1, with only preliminary small-cohort sponsor-reported data.
Evidence passport
A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.
Routes recorded
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
Evidence for the assessed benefit
Treatment-attributable weight loss and comparative tolerability are unestablished while the small Phase 1 cohort remains blinded.
Human research context: L3 reflects preliminary blinded human weight and pharmacokinetic observations in eight participants, including two assigned placebo; sponsor-reported, not peer reviewed.
Research maturity, benefit evidence, safety and approval are different questions.
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.
None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.
How far human research has progressed: Phase 1; preliminary sponsor-reported results from a small number of participants
Studied / approved routes
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.
Discovery
Preclinical
Phase I
Furthest established stage
Phase II
Phase III
Approved
Last documented development: 2026 — Phase 1 programme, sponsor updates
A prodrug: an inactive form designed to release the active GLP-1/GIP co-agonist peptide slowly in the body, with the aim of long dosing intervals.
What people claim: that prodrug design will deliver established dual-agonist benefits with far fewer injections. What the evidence actually says: Phase 1 work is under way and the sponsor has reported preliminary findings in a small cohort. Small early cohorts without controlled comparison cannot establish weight, metabolic or tolerability outcomes.
Useful next reads based on this compound — not recommendations.
Tirzepatide evidence profile
A dual GIP and GLP-1 receptor agonist with strong Phase 3 weight and glycaemic data.
Compare MBX 4291 vs Tirzepatide evidence
Same questions, same fields, side by side — including how much human evidence exists.
Claim review: “Tirzepatide improves obstructive sleep apnoea in people with obesity.”
A closely related claim we have graded, from GLP-1s.
GLP-1 Centre
How the incretin medicines compare on trial evidence and where they are actually licensed.
Animal and cell findings are Level 1–2 evidence.
Receptor targets: GLP-1 receptor, GIP receptor
Mechanism class counts the receptors the pharmacology engages and says whether one molecule or several drugs do it. More targets is not the same as more effective, and none of these labels is a receptor name — there is no GLP-3, GLP-4 or GLP-5 receptor.
This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.
No established human signal
Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.
Check the regulatory note and linked primary sources for jurisdiction-specific details.
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.
Preliminary human outcome research, including small or observational studies. Descriptive exposure studies alone do not demonstrate therapeutic benefit.
Source transparency
A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.
Review provenance
Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.
Current linked evidence is sponsor-only. Treat findings as provisional until independent or peer-reviewed documentation is available.
Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.
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.