How often are research summaries updated?

Research summaries are reviewed periodically against the latest peer-reviewed publications and registry updates, and whenever a material change occurs. The 'Last updated' date on each summary reflects the most recent review.

What sources do you cite?

Primary trial publications (NEJM, Lancet, JAMA), regulatory documents (MHRA, EMA, FDA), and the manufacturer's publicly available investigator brochures or registry records. Trial names are cited explicitly so claims can be back-traced.

Do you cover early-phase trial data?

Yes, where it is the highest-quality evidence available — for example, retatrutide is covered with its Phase 2 NEJM data because Phase 3 (TRIUMPH) had not yet read out at the time of review. We flag the trial phase clearly.

Research summaries

Metabolic peptide research summaries

Peer-reviewed literature summarised for UK researchers. Each post fact-checked against the original trial publication or preclinical reference. See also the canonical /trials/ hub for the structured trial intelligence library.

By Metabolic Peptides Editorial TeamReviewed by Scientific Review PanelLast updated 21 May 2026

GLP-1 Receptor Agonists: 2026 Landscape Review

Updated May 2026

A pharmacological and clinical-evidence review of the GLP-1 receptor agonist class as it stood at the start of 2026 — from liraglutide to retatrutide.

Tirzepatide UK Research Update (2026)

Updated May 2026

What changed for tirzepatide research in the UK during 2025-2026: MHRA position, SURMOUNT-MMO interim data, and emerging cardiovascular evidence.

Retatrutide Phase 2 NEJM Summary

Updated May 2026

A close reading of Jastreboff et al. (NEJM 2023) — the Phase 2 retatrutide weight-loss trial that has reframed expectations for triple GLP-1/GIP/glucagon agonism.

Growth-Hormone Fragments vs Secretagogues

Updated May 2026

Why two structurally different families of peptides — lipolytic HGH fragments and GH secretagogues — co-exist in modern metabolic research.

About these summaries

How often are research summaries updated?: Research summaries are reviewed periodically against the latest peer-reviewed publications and registry updates, and whenever a material change occurs. The 'Last updated' date on each summary reflects the most recent review.
What sources do you cite?: Primary trial publications (NEJM, Lancet, JAMA), regulatory documents (MHRA, EMA, FDA), and the manufacturer's publicly available investigator brochures or registry records. Trial names are cited explicitly so claims can be back-traced.
Do you cover early-phase trial data?: Yes, where it is the highest-quality evidence available — for example, retatrutide is covered with its Phase 2 NEJM data because Phase 3 (TRIUMPH) had not yet read out at the time of review. We flag the trial phase clearly.