What makes retatrutide different from semaglutide and tirzepatide?

Retatrutide is a triple agonist that activates three receptors: GIP, GLP-1, and glucagon. Semaglutide activates only GLP-1. Tirzepatide activates GIP and GLP-1. The addition of glucagon receptor agonism in retatrutide increases energy expenditure and promotes hepatic fat oxidation — effects not produced by pure GLP-1 or dual GIP/GLP-1 agonism. This triple mechanism produced 24.2% weight loss in Phase 2 trials, exceeding both semaglutide (~15%) and tirzepatide (~21%).

Is retatrutide FDA-approved?

No. Retatrutide is currently in Phase 3 clinical trials (the TRIUMPH program) conducted by Eli Lilly. It has not been submitted to the FDA for approval. Phase 3 results are expected between 2025 and 2027. If results confirm Phase 2 findings, an FDA submission could follow, with potential approval in the 2027-2028 timeframe.

Can I buy retatrutide?

Retatrutide is available from research peptide vendors as a research chemical, not for human use. It cannot be legally prescribed or compounded for clinical use because it has no FDA-approved version. Purchasing research peptides for self-administration carries significant legal and safety risks, including unknown purity, lack of medical supervision, and potential legal liability. TriedRx tracks 48 vendors and 312 samples for quality data, but does not endorse self-administration of unapproved compounds.

How much weight loss does retatrutide produce?

In the Phase 2 trial, retatrutide at 12mg produced 24.2% average body weight loss over 48 weeks. The weight-loss curve had not plateaued at 48 weeks, suggesting longer treatment could produce even greater loss. At 8mg, weight loss was 22.8%. These results exceed all other anti-obesity drugs tested to date. Phase 3 trials will confirm whether these results hold in larger populations.

What are the side effects of retatrutide?

The most common side effects in Phase 2 were gastrointestinal: nausea (22-35%), diarrhea (22-30%), vomiting (6-19%), constipation (13-16%), and decreased appetite (9-28%). A small increase in resting heart rate (~3-4 bpm) was observed, possibly related to the glucagon agonist component. The discontinuation rate due to adverse events was approximately 6% at the highest dose. Full safety profiles will be available from the Phase 3 TRIUMPH program.

Does retatrutide help with fatty liver disease?

Yes, retatrutide showed remarkable effects on liver fat in Phase 2. Participants receiving 12mg experienced an average 82-86% reduction in liver fat measured by MRI, and 93% of those with MASLD at baseline achieved liver fat normalization. These results likely reflect the glucagon receptor's role in promoting hepatic fat oxidation. Eli Lilly is conducting a dedicated Phase 3 trial (TRIUMPH-3) for MASH based on these findings.

When will retatrutide be available?

If Phase 3 results are positive and regulatory review proceeds on schedule, retatrutide could receive FDA approval in approximately 2027-2028. However, drug development timelines are subject to delays from clinical, manufacturing, or regulatory factors. There is no guarantee of approval — Phase 3 results must confirm Phase 2 efficacy and safety findings in larger populations.

Vendor Rankings

Independent rankings of peptide vendors based on aggregated lab data, COA transparency, community sentiment, and verified pricing. We publish everything — including the failures.

3,279+ samples tracked 566 vendors ranked 15 peptides tracked

All BPC-157 Tirzepatide Semaglutide CJC-1295 Ipamorelin GHK-Cu Retatrutide Tesamorelin

AGreat

B+Very Good

BGood

COkay

DPoor

EBad

FFraud

Retatrutide Rankings

HUMAN TRIALS

3,279 samples across 566 vendors · Updated weekly from independent lab testing

#	Vendor	Avg score	Purity range	Tests	Verified $/mg	Grade	Profile
Grade A — Great
1	ZLZ Peptide	9.3	—	102	—	A	review →
2	SRY Labs	9.3	—	31	—	A	review →
3	Nantong Guangyuan Chemical GYC	9.2	—	19	—	A	review →
4	Inno Peptides	9.1	—	16	—	A	review →
5	Allen Biotechnology Co ABC	9.1	—	14	—	A	review →
6	Zenith Jove Peptide ZJ	9.1	—	24	—	A	review →
7	Chimera Peptides	9.1	—	14	—	A	review →
8	Lipeptides	9.1	—	26	—	A	review →
9	Heman Peptide HM	9.1	—	50	—	A	review →
10	Shanghai ERP peptide Biotechnology	9.0	—	53	—	A	review →
Grade B+ — Very Good
11	Bfflist AMO	9.0	—	48	—	B+	review →
12	Huayi Biotechnology	9.0	—	21	—	B+	review →
13	Top Peptide	9.0	—	11	—	B+	review →
14	PeptiSlim	8.9	—	26	—	B+	review →
15	Homopeptide	8.9	—	11	—	B+	review →
16	Baoju Chemical	8.9	—	8	—	B+	review →
17	HK Peptides	8.9	—	137	—	B+	review →
18	Shanghai Wibson Biotechnology WBS	8.9	—	18	—	B+	review →
19	Andy Peps Studio	8.9	—	12	—	B+	review →
20	Wuhan Wansheng Biotechnology	8.9	—	70	—	B+	review →
21	YB Peptide	8.9	—	8	—	B+	review →
22	Reta-Peptide	8.8	—	81	—	B+	review →
23	Amino Lair	8.8	—	10	—	B+	review →
24	Tianjin Finder Chemical TFC	8.8	—	39	—	B+	review →
25	Aavant Research	8.8	—	7	—	B+	review →
26	Mai Peptide	8.8	—	34	—	B+	review →
27	Shanghai Baoju	8.8	—	28	—	B+	review →
28	Hebei Rimao Technology	8.7	—	22	—	B+	review →
29	Zztai Peptide	8.7	—	11	—	B+	review →
30	GGPeps	8.7	—	5	—	B+	review →
31	Guangzhou Jeep Biotechnology JEEP	8.7	—	18	—	B+	review →
32	Jinan Elitepeptide Chemical JEC JCE	8.7	—	5	—	B+	review →
33	Shanghai Huahaige Plastic	8.7	—	5	—	B+	review →
34	Zhuoyue Biotechnology	8.6	—	11	—	B+	review →
35	Nova Peptide	8.6	—	4	—	B+	review →
36	Cellupep	8.6	—	14	—	B+	review →
37	NovaPeptide	8.6	—	6	—	B+	review →
38	Tirz Peptide	8.6	—	4	—	B+	review →
39	Qingfuji Trading	8.6	—	4	—	B+	review →
40	PepClub USA	8.6	—	4	—	B+	review →
41	Superior Peptides	8.6	—	4	—	B+	review →
42	WllyBIO	8.6	—	14	—	B+	review →
43	Shandong Aishi Biotechnology	8.6	—	24	—	B+	review →
44	Peptide Pole Hongkong	8.6	—	12	—	B+	review →
45	Lejian Biotech Peptide	8.6	—	8	—	B+	review →
46	Retalux	8.6	—	8	—	B+	review →
47	SPB	8.5	—	4	—	B+	review →
48	Bfflink	8.5	—	23	—	B+	review →
49	Huaian Hanyou Peptide	8.5	—	28	—	B+	review →
50	ZZQ Peptides	8.5	—	17	—	B+	review →

Verified $/mg = list price ÷ (avg tested qty / labeled qty). Vendors below the cutoff omitted from view.