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Laboratory research compound — in vitro use only
Retatrutide is supplied by RS Bio Labs strictly as a laboratory research material for qualified scientific personnel. It is not approved, intended or authorised for human consumption, self-administration, diagnostic, therapeutic or veterinary use. All answers below are drawn from published preclinical or clinical-trial literature and do not constitute medical advice or establish safety in any unapproved setting.
Retatrutide is supplied by RS Bio Labs strictly as a laboratory research material for qualified scientific personnel. It is not approved, intended or authorised for human consumption, self-administration, diagnostic, therapeutic or veterinary use. All answers below are drawn from published preclinical or clinical-trial literature and do not constitute medical advice or establish safety in any unapproved setting.
Retatrutide is the most-studied compound at the frontier of incretin research, and it generates a lot of questions — from its mechanism and trial data through to the practical side of handling a lyophilised research peptide. We have gathered the most common ones here in a single hub.
The answers are deliberately concise; wherever a question deserves a fuller treatment, we link to the dedicated guide. Tap any question to expand its answer.
About Retatrutide
What is Retatrutide?
Retatrutide (LY3437943) is a synthetic, fatty-acid-conjugated long-acting peptide developed by Eli Lilly. It is the first compound to activate three metabolic receptors — GIP, GLP-1 and glucagon — at once, which is why the literature calls it a triple agonist. See the full What Is Retatrutide? guide.
What does "triple agonist" mean?
A single Retatrutide molecule binds and activates three related receptors — GIP, GLP-1 and glucagon (a "GGG tri-agonist"). This puts it one generation beyond dual agonists like Tirzepatide (GIP/GLP-1) and single agonists like Semaglutide (GLP-1). Our GLP-1 vs GIP vs Glucagon guide breaks down each pathway.
How does Retatrutide work?
The GLP-1 and GIP receptors are studied for appetite suppression, slowed gastric emptying and glucose-dependent insulin secretion, while the glucagon receptor is associated with increased resting energy expenditure and hepatic lipid mobilisation. In research models the net effect is reduced energy intake alongside increased energy expenditure — a combination not achievable with monotherapy.
How does Retatrutide compare to Tirzepatide?
Tirzepatide is an FDA-approved dual GIP/GLP-1 agonist that reached ~22.5% weight reduction in its pivotal trial; Retatrutide adds the third glucagon target and reached ~24.2% in Phase 2 without the curve plateauing. See the full Retatrutide vs Tirzepatide comparison.
How does Retatrutide compare to Semaglutide?
Semaglutide is a single GLP-1 agonist that delivered ~15% in its pivotal trial. Retatrutide engages two additional receptors (GIP and glucagon) and reported the largest incretin-class effect to date at ~24.2% in Phase 2. The mechanistic difference is covered in GLP-1 vs GIP vs Glucagon.
What are Retatrutide's key trial results?
The Phase 2 TRIUMPH-1 trial (Jastreboff et al., New England Journal of Medicine, 2023) reported mean body-weight reduction of approximately 24.2% at 48 weeks on the 12 mg dose — the largest for any incretin-class compound so far. A concise round-up is in our Research Summary.
What is Retatrutide's half-life?
Approximately six days, thanks to its C20 fatty-acid conjugation and albumin binding — which is why research protocols follow a once-weekly schedule. Full detail in the Retatrutide Half-Life guide.
How often is Retatrutide used in research?
Once weekly. The ~6-day half-life means a single weekly interval maintains relatively steady exposure in research models, which is the schedule used throughout the clinical programme. See the half-life guide for the pharmacokinetic reasoning.
Handling & Storage
How is Retatrutide supplied?
As a sterile lyophilised (freeze-dried) powder in sealed vials, measured in milligrams (RS Bio Labs stocks 10mg, 30mg and 60mg among others). It is reconstituted with bacteriostatic water before use in a research setting.
What water is used to reconstitute Retatrutide?
Bacteriostatic water — sterile water containing 0.9% benzyl alcohol, which lets the reconstituted vial be used over several days. Mixing ratios and worked concentration examples are in Reconstituting Retatrutide.
How do I store Retatrutide?
Sealed lyophilised vials are stable refrigerated and can be kept frozen for long-term storage; once reconstituted, the vial is kept refrigerated at 2–8 °C and protected from light. Full temperatures and shelf life are in the Storage Guide.
How long does Retatrutide last once mixed?
Once reconstituted with bacteriostatic water and kept refrigerated, research-grade Retatrutide is generally regarded as usable for around four weeks, with the lyophilised form remaining far more stable. Specifics on reconstituted vs lyophilised stability are in the Storage Guide.
Buying & Research Use
What purity is your Retatrutide, and do you provide a COA?
Every batch is ≥99% purity, verified by third-party HPLC, and a Certificate of Analysis (COA) is provided with every order. This is the same standard applied across all RS Bio Labs research compounds.
Is Retatrutide approved or legal?
Retatrutide is an investigational compound that has not been approved by the MHRA, FDA or any other regulator for any use. RS Bio Labs supplies it lawfully as a research reagent for in vitro laboratory use only.
Is Retatrutide for human use?
No. All products are in-vitro research reagents supplied strictly for qualified scientific personnel. They are not for human consumption, self-administration, diagnostic, therapeutic or veterinary use.
Do you ship to the UK and internationally?
Yes. RS Bio Labs offers free UK shipping with dispatch in 1–2 business days, and ships internationally for a flat fee. Orders are packed discreetly and tracked.
Why buy Retatrutide from RS Bio Labs?
Consistent ≥99% purity, third-party HPLC testing and a COA with every order, plus free UK shipping, 1–2 day dispatch and a full library of research guides. It is research-grade material backed by documentation you can verify.
Retatrutide — Research Grade
≥99% purity, third-party HPLC tested, with a Certificate of Analysis. Free UK shipping · dispatched 1–2 business days. Available in eight strengths — a selection shown below.
Retatrutide 10mg
LY3437943 · lyophilised
Retatrutide 30mg
LY3437943 · lyophilised
Retatrutide 60mg
LY3437943 · best value
Bacteriostatic Water
10ml · for reconstitution
Continue the Retatrutide series
What Is Retatrutide?
The triple GIP/GLP-1/glucagon agonist explained from first principles.
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Retatrutide vs Tirzepatide
Triple vs dual agonist — mechanism, trial data and how the two compare.
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Retatrutide Half-Life
Why ~6 days supports a once-weekly research schedule.
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Storage Guide
Lyophilised vs reconstituted stability, temperatures and shelf life.
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Reconstituting Retatrutide
Mixing ratios, concentrations and technique, worked through.
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Research Summary
TRIUMPH programme and the key published findings at a glance.
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GLP-1 vs GIP vs Glucagon
The three incretin pathways explained and why combining them matters.
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History of Retatrutide
From Eli Lilly's tri-agonist programme to Phase 3.
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