01
GIP
GIP participates in nutrient response and glucose-dependent insulin signalling.
GIP/GLP-1/glucagon receptor triple agonist
Retatrutide
GIP · GLP-1 · Glucagon
Retatrutide (LY3437943) activates three metabolic receptors in one peptide. Phase 2 research showed large mean weight reduction and marked liver-fat reduction; full regulatory review and long-term outcomes are still pending.
3Overview
1× / wkReference frequency
DataPeer-reviewed phase 2 and phase 3 development
Research status
Phase 3; not approved
RETATRUTIDE20 MG
01 · Overview
What is Retatrutide?
Retatrutide (LY3437943) activates three metabolic receptors in one peptide. Phase 2 research showed large mean weight reduction and marked liver-fat reduction; full regulatory review and long-term outcomes are still pending.
Research route, formulation and population determine what a result actually means.
02
GLP-1
GLP-1 signalling affects satiety, gastric emptying and glucose-dependent insulin response.
03
Glucagon
Glucagon-receptor signalling affects liver metabolism and energy expenditure.
02 · Research
What do the studies show?
Peer-reviewed phase 2 and phase 3 development. Educational information. Not diagnosis, treatment or use advice.
24.2%
Phase 2Weight reduction at week 48
In a 338-participant trial, mean change with 12 mg was −24.2%; no clear plateau had been reached at week 48.
82.4%
Phase 2Liver fat in MASLD substudy
At 24 weeks mean liver fat fell markedly with 8 and 12 mg; this was a substudy and does not establish every liver outcome.
28.3%
Phase 3TRIUMPH-1 topline at week 80
Lilly reported a mean −28.3% at week 80 for 12 mg. This is official topline information, not yet a full peer-reviewed phase 3 publication.
03 · DATA
Peptide and product specifications
Checked identity data for this research compound or blend.
RetatrutidePeptide and product specifications
Development code
LY3437943
Developer
Eli Lilly and Company
Molecular formula
C₂₂₁H₃₄₂N₄₆O₆₈
Molecular weight
4.731 kDa (≈4731 Da)
CAS number
2381089-83-2
Amino-acid sequence / components
Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-α-Me-Leu-Leu-Asp-Lys-Lys(AEEA-γGlu-C20-diacid)-Ala-Gln-Aib-Ala-Phe-Ile-Glu-Tyr-Leu-Leu-Glu-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH₂
Amino-acid count
39
Modified residues
Aib at positions 2 and 20; α-methylleucine at position 13; N⁶-substituted lysine with AEEA/γ-glutamate/C20 diacid at position 17; C-terminal serinamide
Pharmacokinetic half-life
Approximately 6 days in clinical pharmacokinetic research
Purity
Batch-specific - confirm identity and purity with the Velora COA
Reference diluent
Formulation- and batch-specific; the USAN document does not prescribe a universal diluent
Unreconstituted-material storage
Formulation- and batch-specific; follow the accompanying COA and validated stability data
These are compound references, not a batch certificate. Purity and identity of a specific Velora batch must be confirmed by its accompanying COA and laboratory report.
Official USAN identity document ↗04 · Calculator
Reconstitution and U-100 conversion
This module only converts concentration and volume. Inputs are not recommendations or individual dosing advice.
Calculator
Once weekly in clinical trials
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Draw to
0 units
0.00 mL
RETATRUTIDE
20 MG
Concentration-
Per unit-
Complete amounts-
Calculated duration-
LAB · RECONSTITUTION
How to reconstitute Retatrutide for laboratory research
A visual workflow for controlled laboratory reconstitution. Always follow the product label, COA and a validated protocol.
Clean
Disinfect the rubber closures of both vials and allow them to dry.
Measure diluent
Withdraw only the diluent validated for the specific compound.
Add slowly
Let the liquid run slowly down the inside wall of the vial.
Swirl gently
Do not shake; rotate gently until the material has dissolved.
Store per protocol
Follow the product label, COA and validated stability data.
Important checks before and after reconstitution
Check the product
First confirm that the product is a lyophilised vial. Prefilled pens and ready-to-use solutions do not require reconstitution. Check the label, COA and specified diluent.
Use clean, sterile technique
Wash your hands, clean the work surface and use new sterile equipment for every procedure. Clean both rubber closures with separate alcohol swabs and let them dry completely.
Concentration, not total amount
The volume of liquid added changes the concentration in mg per mL, but not the total amount of research compound in the vial. Use the calculator to check this in advance.
Inspect and label
Check for unexpected discoloration, cloudiness or visible particles. Record the compound, concentration and reconstitution date. Storage time and temperature are product-specific; a fixed 28-day rule does not apply to every compound.
General reconstitution volumes listed by the source
General examples, not a product-specific protocol. The chosen volume determines concentration; always check the label, COA and calculator.
| Vial strength | Commonly listed volume |
|---|---|
| 2 mg | 1–2 mL |
| 5 mg | 2–3 mL |
| 6 mg | 2–3 mL |
| 10 mg | 2–4 mL |
| 15 mg | 3–5 mL |
| 20 mg | 4–8 mL |
Practical background source: Free Medical Journals - Complete Step-by-Step Guide to Peptide Reconstitution, accessed July 2026. This is a secondary educational source; the product label, COA and validated stability data remain authoritative.
05 · Safety and limitations
Safety and limitations
Research route, formulation and population determine what a result actually means.
What is known
- Visible research claims use primary or official sources.
- The calculator is arithmetic and does not turn a study amount into medical advice.
- A registered medicine and a research vial are not automatically equivalent.
What remains uncertain
- Many products lack long-term safety data and independent replication.
- Animal and cell findings do not predict a safe human dose.
- Stability depends on formulation, pH, sterility, light, temperature and packaging.
Status: Phase 3; not approved. Educational information. Not diagnosis, treatment or use advice.
06 · FAQ
Frequently asked questions
Retatrutide (LY3437943) activates three metabolic receptors in one peptide. Phase 2 research showed large mean weight reduction and marked liver-fat reduction; full regulatory review and long-term outcomes are still pending.
In a 338-participant trial, mean change with 12 mg was −24.2%; no clear plateau had been reached at week 48. At 24 weeks mean liver fat fell markedly with 8 and 12 mg; this was a substudy and does not establish every liver outcome.
No. It performs arithmetic conversions only. Medical decisions belong with a licensed healthcare professional.
The curve follows the agreed storage model and is not a laboratory result.
2–8 °C. Protect from light and repeated freeze-thaw cycles.
07 · Sources
Primary research sources
Educational information. Not diagnosis, treatment or use advice.
Triple–Hormone-Receptor Agonist Retatrutide for Obesity - Phase 2 New England Journal of Medicine, 2023. Link
Retatrutide for metabolic dysfunction-associated steatotic liver disease Nature Medicine, 2024. Link
TRIUMPH-1 phase 3 topline results Eli Lilly and Company, 2026. Link
TRIUMPH master protocol NCT05929066 ClinicalTrials.gov, 2026. Link