GLP-3 RT, Retatrutide, RT3: One Molecule, Many Names
Researchers searching for GLP-3 RT run into a dozen names for the same compound. Suppliers use catalog names instead of the nonproprietary name, and every shop picks a slightly different one. Before comparing prices, confirm you are comparing the same molecule.
| Name | What It Is | Same Molecule? |
|---|---|---|
| Retatrutide | International nonproprietary name (INN) | Yes |
| LY3437943 | Eli Lilly development code used in clinical trials | Yes |
| GLP-3 RT / GLP3-RT / GLP-3 RTA | Research-market catalog names ("GLP-3" = triple agonist class) | Yes |
| RT3 / Reta | Shorthand used by suppliers and researchers | Yes |
| GLP-2 TRZ / GLP-2 TZ | Tirzepatide, a dual GIP/GLP-1 agonist | No |
| GLP-1 SM | Semaglutide, a single GLP-1 agonist | No |
For the full mechanism, receptor pharmacology, and clinical trial background, see our GLP-3 RT (Retatrutide) research guide. This page focuses on buying: price, size, and verification.
GLP-3 RT Price in 2026: Cost per Milligram
Across the U.S. research peptide market in 2026, GLP-3 RT listings typically start around $70 for a 10mg vial, with larger vials priced lower per milligram. Sticker price is misleading because vial sizes vary from 5mg to 40mg between suppliers. The only fair comparison is price ÷ milligrams, then checked against the COA to confirm the vial actually contains what the label says.
| Vial | Price | Cost per mg | COA | Best For |
|---|---|---|---|---|
| 15mg | $119.95 | $8.00 | Batch-matched | Pilot studies, supplier validation |
| 30mg | $189.95 | $6.33 | Batch-matched | Longer studies, single-lot consistency |
A $60 "10mg" vial that tests at 7.5mg of actual peptide costs $8.00 per usable mg, the same as a fully dosed 15mg vial, before accounting for the lost study time when results don't replicate. Net peptide content and purity on the COA are what turn sticker price into real cost.
15mg vs 30mg: Which Vial to Order
Why single-lot matters: switching lots mid-study introduces a variable (purity, net content, counter-ion) that has nothing to do with your hypothesis. Buying enough material up front from one lot is the cheapest reproducibility insurance available.
8-Point Supplier Checklist Before You Buy GLP-3 RT
Retatrutide is a 39-amino-acid peptide with a C20 fatty diacid modification, which makes it harder to synthesize and purify cleanly than short peptides. That's why supplier quality varies more for GLP-3 RT than for simpler compounds. Run every supplier through this list:
- Batch-matched COAThe lot number on the COA matches the lot number on your vial. A generic "sample" COA proves nothing about what you receive.
- Named third-party labThe testing lab is identified by name and is independent of the supplier. In-house-only testing is a conflict of interest.
- HPLC purity ≥99%Purity by high-performance liquid chromatography, with the chromatogram included, not just a number typed on a page.
- Mass spec identityLC-MS or MALDI confirming a molecular weight near 4,731 Da. HPLC alone shows purity, not that it's the right molecule.
- Recent test dateTested within the past 12 months. A COA from 2024 on a 2026 order is a red flag.
- Net peptide contentConfirms how much actual peptide is in the vial versus salts and moisture. This is where under-filled vials are exposed.
- Clear RUO labelingReputable suppliers label for research use only and make no human-use, dosing, or therapeutic claims.
- Fast, tracked fulfillmentLyophilized peptide is stable in transit, but days sitting in a warehouse or truck are avoidable. Same-day dispatch and tracking matter.
How to Read a GLP-3 RT Certificate of Analysis
Purity and identity answer different questions. A sample can be 99% pure and still be the wrong peptide, or a truncated sequence. HPLC tells you how clean the sample is; mass spectrometry tells you what it is. For a lipidated 39-residue peptide like retatrutide, you need both.
GLP-3 RT Supplier Red Flags
| Red Flag | Why It Matters | What Good Looks Like |
|---|---|---|
| "COA available on request" | Hidden data is usually bad data | COAs published publicly before purchase |
| One COA for every lot | Doesn't describe the vial you receive | Lot-specific COA per batch |
| Price far below market | Retatrutide synthesis is not cheap; deep discounts often mean under-fill or impurities | Price per mg in line with market, backed by net content |
| Dosing or weight-loss claims | Signals a non-research operation and invites regulatory action that can shut a supplier down mid-study | Strict RUO labeling, research-only language |
| No MS data | Can't confirm the molecule is retatrutide | Mass spec confirming ~4,731 Da |
| No physical business, no support | No recourse if an order is wrong | U.S. address, reachable support, tracked shipping |
Buying GLP-3 RT From Evo Peptides
Every point on the checklist above is how we run our own GLP-3 RT supply:
| Checkpoint | Evo Peptides |
|---|---|
| Third-party testing | Every batch tested by ILS Laboratories |
| COA access | Published publicly on the COA page before you buy |
| Vial sizes | 15mg ($119.95) · 30mg ($189.95) |
| Same-day shipping | Orders before 3:00 PM CST ship same business day |
| Shipping cost | Free standard shipping on all orders · Free 2-day at $150+ |
| Ships from | Wisconsin, USA |
| Payment | Card, Cash App, Venmo |
| Labeling | Research Use Only; not for human or veterinary use |
GLP-3 RT + GLP-2 TRZ
Labs comparing triple vs dual agonism often run GLP-3 RT alongside GLP-2 TRZ (tirzepatide) to isolate the contribution of glucagon receptor activity. See the GLP-2 TRZ research guide. A combined order of both clears the $150 free 2-day shipping threshold.
What to Do When Your Order Arrives
- Match the lot. Check that the lot number on the vial matches the COA on our COA page. File the COA with your lab records.
- Store lyophilized vials frozen. −20 °C for long-term storage; 2–8 °C for short-term. Keep sealed and away from light.
- Reconstitute only what you need. After reconstitution, refrigerate and minimize freeze-thaw cycles by aliquoting.
- Log everything. Record lot, receipt date, and reconstitution date for reproducibility.
Full handling details are in our peptide storage guide. For pharmacokinetic context, see the peptide half-life chart.
Regulatory Status of Retatrutide (September 2026)
Retatrutide is not FDA-approved and remains investigational. Eli Lilly's Phase 3 TRIUMPH program has reported topline results, including TRIUMPH-1, while several trials, including the cardiovascular and kidney outcomes study, remain active. No approved branded retatrutide product is available, and it cannot be prescribed outside clinical trials.
Research-grade GLP-3 RT is a laboratory reagent, not a pharmaceutical. It is sold for in vitro and laboratory research only, and purchasers confirm research-use intent at checkout.