Triple agonist
Retatrutide
Studied in Phase 3 trials for up to 28.7% body-weight reduction
Mean body-weight reduction
TRIUMPH-4 phase 3 topline, pending peer review
Flat $35 tracked shipping20mg per vial
$205 USD
Add 2 more, unlock 19%
| Test | Result | Verdict |
|---|---|---|
| Purity, HPLC | 99.18% | PASS |
| Identity, LC-MS | 4731.4 Da | PASS |
| Sterility | No growth | PASS |
| Endotoxin | 4.070 EU/Vial | PASS |
| Heavy metals + fentanyl | Not detected | PASS |
Shipping, delivery and guarantee terms
- Shipping
- Flat $35, tracked worldwide to supported markets
- Delivery
- 5 to 10 business days, guaranteed
- Payment
- Card, bank transfer, or crypto · All sales final except a purity failure
- Included
- 60-day money-back guarantee · Third-party batch COA
The short answer
What is retatrutide?
Retatrutide is an investigational triple-receptor agonist that activates the GLP-1, GIP and glucagon pathways at once, studied for body-weight reduction. In the published 48-week phase 2 trial, the 12 mg weekly arm reached a mean body-weight reduction of up to about 24.2 percent, against about 2.1 percent on placebo (Jastreboff et al., 2023). Peptara Labs supplies it as research-grade material, not as a treatment, and those figures are trial group means rather than a prediction for any individual.
Comparing the GLP-1 class
How does retatrutide compare with semaglutide and tirzepatide?
Semaglutide is a single GLP-1 receptor agonist, tirzepatide a GIP and GLP-1 dual agonist, and retatrutide a triple agonist adding glucagon. The three were measured in separate trials with different designs and populations, never head to head, so the honest comparison is trial by trial rather than a ranking. Two research-based comparisons:
Retatrutide vs Ozempic
How the two compare, by mechanism and trial data.
Retatrutide vs Tirzepatide
Where the newer triple-agonist differs from the dual.
Ozempic, Wegovy, and Mounjaro are FDA-approved medications. Research-grade peptides, including ours, are not FDA-approved and are sold for research purposes only. This is education, not medical advice or a treatment claim.
The Science
Triple-Agonist Technology
Retatrutide activates three metabolic receptor pathways at once: GLP-1, GIP and glucagon. Whether that combination outperforms a single or dual agonist has not been tested head to head; the published comparisons come from separate trials with different protocols.
GLP-1 Receptor
Appetite Suppression
GLP-1 receptor signaling is described in the literature as reducing hunger signaling and increasing satiety.
GIP Receptor
Fat Metabolism
GIP receptor signaling is described as modulating insulin response and lipid handling.
Glucagon Receptor
Energy Expenditure
Glucagon receptor signaling is described as raising thermogenesis and resting energy expenditure.
Naming
Is retatrutide a "GLP-3"?
A lot of searches call retatrutide a "GLP-3", but there is no GLP-3 receptor. The label is informal shorthand for its three-receptor design: retatrutide (development code LY3437943) is a single peptide that activates the GIP, GLP-1 and glucagon receptors together (Coskun et al., 2022).
That is the step the class implies: semaglutide is a single GLP-1 agonist, tirzepatide is a dual GIP and GLP-1 agonist, and retatrutide adds glucagon to make three. "Triple agonist" is the accurate description; "GLP-3" is a nickname, not a drug class.
Clinical Data
Clinical Trial Results
28.7%
Average Weight Loss
68 weeks
58.6%
Achieved 25%+ Loss
of participants
445
Trial Participants
Phase 3
Data from the Phase 3 TRIUMPH-4 trial of retatrutide, reported by Eli Lilly (topline, 2025). Results represent participants receiving the 12mg maintenance dose over 68 weeks; detailed results are pending peer-reviewed publication. Individual results may vary.
Comparison
Tirzepatide vs retatrutide: what the separate trials reported
This is the question behind most "tirzepatide vs retatrutide" searches. The two have not been tested head to head, so the figures below come from separate trials with different designs and populations. Read them as parallel records, not a race result.
| Compound | Receptor targets | Top reported mean weight loss | Source |
|---|---|---|---|
| Tirzepatide | GIP and GLP-1 | up to about 22.5 percent (SURMOUNT-1) | Jastreboff et al., NEJM 2022 |
| Retatrutide | GIP, GLP-1 and glucagon | up to about 24.2 percent at 48 weeks (phase 2) | Jastreboff et al., NEJM 2023 |
Retatrutide is still investigational, while tirzepatide is FDA-approved with an extensive clinical safety record, so effect size is only one axis of the comparison. A fuller side-by-side, including the phase 3 TRIUMPH-4 topline of about 28.7 percent at 68 weeks, is on our retatrutide vs tirzepatide comparison.
Research Timeline
What the studies measured, and when
Research Timeline
What the studies measured, and when
Research timeline
What the studies measured, and when
The trial
A 48-week phase 2 trial enrolled 338 adults and escalated gradually to one of four weekly maintenance arms: 1, 4, 8 or 12 mg by subcutaneous injection (Jastreboff et al., NEJM 2023; doi:10.1056/NEJMoa2301972).
Dose response
Mean body-weight change was dose dependent across those four arms, largest in the 12 mg arm (Jastreboff et al., 2023).
48 weeks
The 12 mg arm reached up to about 24.2 percent mean body-weight reduction at 48 weeks, against about 2.1 percent on placebo (Jastreboff et al., 2023).
68 weeks
Eli Lilly later reported a phase 3 TRIUMPH-4 topline of about 28.7 percent at 68 weeks in the 12 mg group, pending peer-reviewed publication.
Your Kit
What's Included
$205 USD
Flat $35 shipping · All sales final
Retatrutide 20mg Vial
20mg per vial · Lyophilized powder, sealed vial
Study Protocol Reference (educational)
Ranges and titration schedules reported in published studies. Not a prescription; consult a licensed physician.
Worldwide Shipping
5 to 10 business days, guaranteed
Ongoing Support
Direct team access
Your kit includes the vials and bacteriostatic water. Insulin syringes ship to select delivery regions; where they can't ship, we send a same-day sourcing link. A printed reference guide ships with every order.
Traveling with your order
Freeze-dried vials travel well; reconstituted vials travel cold. Rules vary by country. Share your dates when you order.
Why your vials arrive plain
Unlabeled on purpose: discreet, and standard for research-grade material. Match a batch to its certificate with your order number. See the COA page.
Verified orders
What buyers said about their Retatrutide order
4.97 · 33 reviews from orders containing this vial. Published word for word.
a friend from my BJJ class mentioned them while we were waiting for our session to start, basically one sentence about how their shipping to vietnam has been reliable. looked into it that night and ordered two vials, both arrived sealed clean no issues
Anonymous - Cần Thơ
Verified order · Retatrutide, MOTS-c · Aug 30, 2026
the vial arrived with the label straight and legible which sounds minor but i have had enough orders where that was not the case to appreciate when it is done right. no peeling, no smudging, nothing to double check a second time
Faye - Cần Thơ
Verified order · Retatrutide · Aug 28, 2026
ChatGPT actually recommended them to me when i was trying to figure out which vendors posted real hplc reports and it pulled up peptara first with a link straight to their lab results page. did my own digging after that and everything checked out, so ordered for the first time this month
K - Hanoi
Verified order · Retatrutide, SLU-PP-332 · Aug 26, 2026
the box arrived with clean edges and nothing shifted inside when i lifted it off the counter. most suppliers get the handling details wrong in small ways, and this one did not
Duc - Da Lat
Verified order · Retatrutide, CJC-1295 / Ipamorelin · Aug 22, 2026
a colleague mentioned them during a break and i had almost forgotten about it by the next day. then i saw their name again in a different context and decided to just go ahead rather than keep putting it off like i usually do
Quan - Hanoi
Verified order · Retatrutide, CJC-1295 / Ipamorelin · Aug 17, 2026
gemini suggested them when i was comparing vendors for a friend who travels a lot. did my own verification after that, batch numbers all check out on the site, both vials plus the ghk arrived sealed properly with clear liquid and no shifting in the tray
Anonymous - Hanoi
Verified order · BPC-157, Retatrutide, GHK-Cu · Aug 14, 2026
Our Guarantee
We Stand Behind Our Quality.
Peptara Labs supplies research-grade Retatrutide, third-party tested with a certificate of analysis on every batch. The guarantee is on the material and on how the order is handled. It is not a guarantee of any outcome, and it is not conditioned on one either.
60-Day Money Back Guarantee
Test it at any lab, or your money back
Send any vial to an independent lab within 60 days of delivery. If it does not test as stated on its certificate of analysis (COA), or your order was not handled correctly, you get a full refund. The 60 days is your window to verify us, not a shelf life. The guarantee is on product quality, never on a health outcome.
Study Protocol Reference, Included
Every order includes a written reference to the dose ranges published studies used, with the study named, plus support at no extra cost. This is not a prescription; consult a licensed physician.
Direct WhatsApp Access
Every order includes direct access to our support team. Questions about certificates, reconstitution, storage, shipping or an order, message us any time and a real person responds.
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Consistently rated by our customers
Quality guarantee: full refund on any purity failure. All sales otherwise final. The 60-day money back guarantee covers product purity, certificate of analysis, and fulfillment. It is not conditioned on any outcome and does not promise one. This is educational information, not medical advice; consult a licensed physician.
Retatrutide FAQ
Order Retatrutide, 20mg vial
Order Retatrutide today. Worldwide shipping, 5 to 10 business days, guaranteed.
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Also in a kit
Retatrutide is in two research kits
A kit groups catalog compounds from one research area and is priced at 35 percent off their combined retail. It is a grouping for browsing related research, not a protocol, and no kit has been tested as a combination.
Pantheon kit
Multi-system research
Retatrutide, Tesamorelin, MOTS-c, TB-500, BPC-157, CJC-1295 / Ipamorelin, Glutathione, KLOW Combo, GHK-Cu, PT-141 (Bremelanotide)
Phoenix kit
Weight & appetite research
Retatrutide ×2, BPC-157 ×2, Glutathione ×2
Research and citations
Peer-reviewed sources
- Jastreboff AM, et al. (2023). Triple-Hormone-Receptor Agonist Retatrutide for Obesity. A Phase 2 Trial. New England Journal of Medicine. doi.org/10.1056/NEJMoa2301972
- Coskun T, et al. (2022). LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept. Cell Metabolism. doi.org/10.1016/j.cmet.2022.07.013
Citations refer to the peer-reviewed publications these figures are taken from. Every dose range reported on this site is the range a named study used. Not a substitute for medical advice.
Keep reading
Retatrutide research guides
Retatrutide price per vial
Full cost breakdown per vial and per mg, plus email-signup pricing.
Retatrutide dosage
What the phase 2 trial arms used, in units not mL.
How to reconstitute retatrutide
Concentration math for the 20mg vial at 1, 2 and 3 mL of bacteriostatic water.
Retatrutide side effects
Reported effects and how often they occurred.
Retatrutide results timeline
What the trial measured week by week.
Retatrutide half-life
Why it is dosed once weekly.
Retatrutide and weight loss
The 24.2 percent phase 2 body-weight figure in plain terms.
Retatrutide before and after data
What the published trial measured across its 48 weeks.
Where to buy retatrutide
Why it is research-only, and how to verify a source by its COA.