Plain, practical guides for researchers who handle peptides: how to check what arrives, how to store and reconstitute it properly, and how to read the test results behind each batch. Written by the NordPeps team.
Retatrutide acts on three receptors at once: GLP-1, GIP and glucagon. A plain-language look at the mechanism, what the trials have found, and where approval stands in 2026.
Read the guide →Guide 02 · Approval statusThe short answer for 2026 is no. Retatrutide is still investigational, with its Phase 3 TRIUMPH programme under way. Where it stands now, the likely timeline, and what the research-use-only label covers.
Read the guide →Guide 03 · CompareA triple agonist set against a dual agonist. Mechanism, trial outcomes and regulatory status compared, with tirzepatide sold as Mounjaro and Zepbound.
Read the guide →Guide 04 · ExplainerRetatrutide in plain terms: an experimental once-weekly triple agonist developed by Eli Lilly, what it does, and whether any regulator has approved it.
Read the guide →Lab toolEnter vial size and solvent volume to get the concentration, the draw volume and the matching U-100 syringe units. Installable, and it works without a connection.
Use the calculator →Guide 05 · CompareSemaglutide (Ozempic) targets one receptor, GLP-1. Retatrutide targets three: GLP-1, GIP and glucagon. How the two compare, including the weight-change results from their clinical trials. For education and research reference.
Read the guide →Guide 06 · CompareAn investigational weekly injection acting on three receptors, set against orforglipron (Foundayo), a daily pill acting on one. Trial results, discontinuations due to side effects, and approval status in 2026. For education and research reference.
Read the guide →Guide 07 · CompareTwo receptors against one: tirzepatide (Mounjaro) and semaglutide (Ozempic, Wegovy). Their first head-to-head trial reported −20.2% versus −13.7% body weight at 72 weeks. For education and research reference.
Read the guide →Guide 08 · CertificatesHow to read a peptide CoA section by section: HPLC purity, identity by mass spectrometry, endotoxin results, and the signs of a weak or recycled certificate.
Read the guide →Guide 09 · Bench practiceTemperature options for freeze-dried peptides, protection from moisture, light and oxygen, freeze-thaw cycles, shelf life, and handling reconstituted solutions.
Read the guide →Guide 10 · TestingWhat a purity figure measures, how HPLC and mass spectrometry produce their results, and why purity, identity and net peptide content each need reading on their own.
Read the guide →Guide 11 · FundamentalsA plain-English introduction: what counts as a research peptide, how they are produced and checked, and what the research-use-only label covers.
Read the guide →Guide 12 · Bench practiceReconstitution as a lab procedure: choosing a solvent, calculating concentration, handling technique that protects the peptide, and storing the solution.
Read the guide →Guide 13 · TestingWhat endotoxins are, how the LAL assay measures them, what EU/mg values mean, and where to find endotoxin and sterility results on a certificate.
Read the guide →Guide 14 · SolventsWhat each liquid contains, why bacteriostatic water is the usual default for multi-use vials, and when sterile water or another solvent is used instead.
Read the guide →Guide 15 · CompareSemaglutide acts on one receptor, tirzepatide on two and retatrutide on three. Which receptors each compound targets, and how far each has got with regulators.
Read the guide →Guide 16 · SourcingA checklist for judging a supplier: independent testing, batch-specific certificates, chromatograms, identity data, and the warning signs of weak material.
Read the guide →Guide 17 · Short answerIt depends on the peptide and the diluent; a common conservative rule for an opened multi-dose vial is 28 days at 2–8 °C. How to store it and when to throw it out.
Read the guide →Guide 18 · Short answerA reconstituted solution needs the fridge. Sealed lyophilized powder is more tolerant, but it still keeps longest when cold.
Read the guide →Batch certificates are published on our certificates page when available. Shipped from within the EU.
See Retatrutide| Compound | GLP-1 | GIP | Glucagon |
|---|---|---|---|
| Semaglutide | Yes | No | No |
| Tirzepatide | Yes | Yes | No |
| Retatrutide | Yes | Yes | Yes |
Receptor targets as described in published research. This compares molecules, not effects in people. All three are sold for laboratory research only.
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