Peptides / Weight and metabolic

Synthetic analog · 39 amino acids · 4,731.3 Da

Retatrutide

Not approvedBanned in sport

Retatrutide is an experimental drug that acts on the GIP, GLP-1 and glucagon receptors, in phase 3 trials for obesity and not approved. Studies in people tested it for weight loss, blood sugar, liver fat and appetite, and tracked stomach side effects. PepBank shows 255 results on retatrutide from 39 studies in people, and 125 from animal and lab studies. The strongest evidence is a randomized trial in people. Data as of 2026-10-30.

Also known as RTA, Reta, LY-3437943, LY3437943, GLP-3, GLP-3 RT and 1 more

39 amino acids, from first to last5 changed amino acids

Evidence level: Large trials in people255 of 380 results come from studies in people, including randomized trials.

Results in people

255

67% of 380 results

Results in animals

104

27% of 380 results

Results in lab cells

21

6% of 380 results

From computer models

0

0% of 380 results

Overview

Key points

Retatrutide (Reta) is a drug in development at Eli Lilly that activates the GIP, GLP-1 and glucagon receptors.^1,2,3,4,5
In a phase 3 trial in adults with obesity and type 2 diabetes, retatrutide reduced body weight more than placebo at week 80.⁶
It is not approved in the US or the EU, and the FDA status is investigational.^7,8
The WADA Prohibited List does not name retatrutide, although the wording of its S0 class for unapproved substances would cover it.⁹

Retatrutide at a glance

What it is	Synthetic analog, 39 amino acids
Approval	Not approved for any use
In sport	Banned in sport (WADA S0)
Studies	63 studies with results. 54 of them gave retatrutide, with 380 results. 255 in people104 in animals21 in lab cells
Best study in people	Randomized controlled trial with 581 people (2026)
Clinical trials	34 registered: 11 active or planned, 2 with posted results
Community use	Weight loss and appetite control; Use alone, not stacked with other GLP-1 drugs (most reports)

The science

What is retatrutide?

Retatrutide (Reta) is a lab-made peptide, which is a chain of amino acids, built on the backbone of human GIP (gastric inhibitory polypeptide).¹ Eli Lilly is developing it under the code LY3437943.^1,5

Other names include RTA, Triple G and GLP-3.¹

39

Amino acids in one chain¹

The history of retatrutide

2019March
A phase 1 safety study of a single injection of retatrutide in healthy participants began, with 45 people enrolled.^1,10
2021May
A phase 2 trial of retatrutide in people with type 2 diabetes began, with 281 people enrolled.^1,11
2022
The oldest paper on retatrutide in PepBank is from 2022.¹²
2023July
The phase 3 trials TRIUMPH-1 and TRIUMPH-2 began on 10 and 11 July, with 2,335 and 1,152 people enrolled.^13,14
2024April
TRIUMPH-Outcomes, a phase 3 trial of cardiovascular and kidney outcomes in adults with obesity, began on 30 April with an enrollment of 10,000.¹⁵
2026July
Eli Lilly reported topline results from the phase 3 trials TRIUMPH-2 and TRIUMPH-3 on 23 July.⁵

Retatrutide structure and chemistry

The key facts about the molecule. Long codes are in the closed section below.

Sequence, 39 amino acidsFrom the first amino acid to the last

Y1XQGT5FTS−DY10SIXL−D15+K+KAQX20AFI−EY25LL−EGG30PSSGA35PPPS

Darker means more water-repelling+ and − show charge in the bodyOutlined: changed amino acid

Structure

Retatrutide is a ring-free chain of 39 amino acids, with three non-standard amino acids, one lysine that carries a fatty diacid, and an amide at the end.¹

Formula

C₂₂₁H₃₄₂N₄₆O₆₈

Molecular weight

4,731.3 g/mol

CAS number

2381089-83-2

Targets

Gastric inhibitory polypeptide receptor (gene GIPR): agonistEvidence: primary literatureGlucagon-like peptide 1 receptor (gene GLP1R): agonistEvidence: primary literatureGlucagon receptor (gene GCGR): agonistEvidence: primary literature

Development

Eli Lilly and Company. Highest phase: phase 3.

Identifiers

PubChem 171934787, ChEMBL CHEMBL5095485, UNII NOP2Y096GV, DrugBank DB18993, KEGG D12430, IUPHAR 13769, PDB 8YW3

Full sequence, SMILES and InChIKey

Three-letter sequence
H-Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-alphaMeLeu-Leu-Asp-Lys-Lys[N6-(AEEA-gammaGlu-CO-(CH2)18-COOH)]-Ala-Gln-Aib-Ala-Phe-Ile-Glu-Tyr-Leu-Leu-Glu-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2

InChIKey
MLOLQJNKXBNWFW-JMUPIODPSA-N

SMILES
CC[C@H](C)[C@@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC1=CC=C(C=C1)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(=O)O)C(=O)NCC(=O)NCC(=O)N2CCC[C@H]2C(=O)N[C@@H](CO)C(=O)N[C@@H](CO)C(=O)NCC(=O)N[C@@H](C)C(=O)N3CCC[C@H]3C(=O)N4CCC[C@H]4C(=O)N5CCC[C@H]5C(=O)N[C@@H](CO)C(=O)N)NC(=O)[C@H](CC6=CC=CC=C6)NC(=O)[C@H](C)NC(=O)C(C)(C)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@H](C)NC(=O)[C@H](CCCCNC(=O)COCCOCCNC(=O)CC[C@@H](C(=O)O)NC(=O)CCCCCCCCCCCCCCCCCCC(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@](C)(CC(C)C)NC(=O)[C@H]([C@@H](C)CC)NC(=O)[C@H](CO)NC(=O)[C@H](CC7=CC=C(C=C7)O)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CO)NC(=O)[C@H]([C@@H](C)O)NC(=O)[C@H](CC8=CC=CC=C8)NC(=O)[C@H]([C@@H](C)O)NC(=O)CNC(=O)[C@H](CCC(=O)N)NC(=O)C(C)(C)NC(=O)[C@H](CC9=CC=C(C=C9)O)N

See charge, composition and 3D structure on the Scientific page

How does retatrutide work?

Step 1Retatrutide switches on three hormone receptors

Step 2In trials, adults lost more weight than with placebo^2,3,4,6,16

A 2022 paper by Coskun and colleagues describes retatrutide as an agonist at all three receptors, which means it activates them.^1,2,3,4 In adults with obesity in a phase 2 trial, retatrutide raised heart rate, with a peak at 24 weeks.¹⁶

In peopleIn mice

In mice with diabetes, retatrutide lowered the inflammation markers TNF-α, caspase-1 and NLRP3 in the kidneys.¹⁷ These kidney results come from mice, so they do not show how retatrutide acts in people.¹⁷

The evidence

What retatrutide studies show

Results grouped by what the studies measured. Each card shows where its results come from.

Large trials in people255 of 380 results come from studies in people, including randomized trials.

Weight and appetite

117 results · 92 in people · 25 animal

In a phase 2 trial in adults with type 2 diabetes, retatrutide lowered overall appetite and hunger more than placebo at week 24.¹⁸

Top results

Blood sugar

32 results · 26 in people · 6 animal

In adults with type 2 diabetes, retatrutide lowered HbA1c more than placebo at week 40 in a phase 3 trial, and daily blood glucose was lower than with placebo after 12 weeks in a phase 1b trial.^19,20

Top results

Cholesterol and blood fats

27 results · 16 in people · 11 animal

In people with type 2 diabetes and in people with obesity or overweight but without diabetes, retatrutide lowered triglycerides, and this went together with lower blood levels of the ANGPTL3/8 complex.²¹

Top results

In adults with obesity or overweight, retatrutide lowered non-HDL cholesterol more than placebo, with or without type 2 diabetes. (Diabetes, obesity & metabolism, 2026)
In people with type 2 diabetes, retatrutide at 8 and 12 mg lowered blood levels of the ANGPTL3/8 complex. (Diabetes, obesity & metabolism, 2025)
In a pooled analysis of trials in adults with overweight or obesity without diabetes, retatrutide was most effective of the drugs for improving blood lipids. (Journal of diabetes, 2025)

Liver

20 results · 13 in people · 7 animal

In adults with fatty liver disease, retatrutide lowered liver fat more than placebo at 24 weeks, and a pooled analysis of trials found it showed the largest liver fat reduction among the GLP-1 based drugs.^22,23

Top results

In adults with fatty liver disease, retatrutide 1 mg lowered liver fat more than placebo at 24 weeks. (Nature medicine, 2024)
In a pooled analysis of trials in fatty liver disease, retatrutide showed the largest liver fat reduction among the GLP-1-based drugs. (The Journal of clinical endocrinology and metabolism, 2025)
In adults with fatty liver disease, retatrutide 4 mg lowered liver fat more than placebo at 24 weeks. (Nature medicine, 2024)

Kidneys and bladder

14 results · 9 in people · 5 animal

In adults with type 2 diabetes, retatrutide lowered a urine kidney marker more than placebo at 36 weeks, while kidney filtration did not differ from placebo.²⁴

Top results

In adults with type 2 diabetes, retatrutide 12 mg lowered a urine kidney marker (UACR) more than placebo. (Kidney international reports, 2025)
Secondary analyses of retatrutide trials pointed to lower albuminuria, a possible kidney benefit. (Maedica, 2025)
In adults with type 2 diabetes, kidney filtration (eGFR) with retatrutide 12 mg did not differ from placebo. (Kidney international reports, 2025)

Heart and blood vessels

12 results · 6 in people · 1 animal · 5 lab

In a pooled analysis of three trials in 878 people with obesity, retatrutide lowered systolic and diastolic blood pressure more than placebo, and in mice, weight loss with the drug made atrial fibrillation harder to trigger.^25,26

Top results

In people with obesity, retatrutide lowered systolic blood pressure more than placebo across three pooled trials. (Proceedings, 2025)
In adults with obesity, retatrutide raised heart rate in a dose-dependent way, peaking at 24 weeks and then declining. (The New England journal of medicine, 2023)
In a pooled analysis of trials, retatrutide lowered systolic blood pressure. (High blood pressure & cardiovascular prevention, 2026)

All 63 retatrutide studies by area Open the Scientific page

Key retatrutide studies

Studies in people come first, then studies in animals and in the lab.

People
Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial
Bellido et al. 2026 · Lancet (London, England) · 581 people · cited by 0
21 results
People
Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity
Jastreboff et al. 2026 · The New England journal of medicine · 574 people · cited by 0
16 results
People
Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA
Rosenstock et al. 2023 · Lancet (London, England) · 281 people · cited by 309
22 results
People
Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial
Coskun et al. 2025 · The lancet. Diabetes & endocrinology · 189 people · cited by 39
13 results
People
Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial
Sanyal et al. 2024 · Nature medicine · 98 people · cited by 228
12 results

All 63 Retatrutide studies

Retatrutide clinical trials

ClinicalTrials.gov lists 34 trials of retatrutide. 11 are active or planned, and 2 have posted results. PepBank does not show trial results.

Solid bars are dates that happened. Hatched bars are planned dates. Data from ClinicalTrials.gov.

The Effect of Retatrutide Once Weekly on Cardiovascular Outcomes and Kidney Outcomes in Adults Living With Obesity (TRIUMPH-Outcomes)

Phase 3active, not recruiting10,000 planned

A Master Protocol of Multiple Agents in Adults With Metabolic Dysfunction-Associated Steatotic Liver Disease (SYNERGY-Outcomes)

Phase 3recruiting4,500 planned

A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight

Phase 3completed2,335 people

All 6 Retatrutide trials

Status and safety

Is retatrutide approved?

FDA

United States

Investigational

Investigational.

EMA

European Union

Not approved

No approved medicine contains it.

WADA

Sport

Banned

On the 2026 Prohibited List, section S0.

No. Not approved for any use. Its most advanced trial is in phase 3. The FDA, the EMA and the other sources we use show no approval (as of 9 Oct 2026). Banned in sport (WADA S0).

Laws and labels change, so check the regulator for the current status.

Retatrutide side effects and safety

PepBank has 61 safety results from studies of retatrutide. 61 of them come from studies in people.

Safety results from studies (61)

In adults with type 2 diabetes, 63% of people given retatrutide reported side effects, compared with 54% on placebo and 60% on dulaglutide. (Lancet, 2022)
In adults with obesity and type 2 diabetes, stopping treatment for side effects or death was not more common with retatrutide 4 mg than placebo. (Lancet, 2026)
In adults with type 2 diabetes given retatrutide, no severe low blood sugar was reported during the study. (Lancet, 2023)
In adults with type 2 diabetes, side effects with retatrutide were similar to those with placebo and dulaglutide. (The lancet. Diabetes & endocrinology, 2025)
In adults with obesity, the most common retatrutide side effects were stomach and gut problems, mostly mild to moderate and dose-related. (The New England journal of medicine, 2023)
In adults with type 2 diabetes, retatrutide most often caused mild to moderate stomach and gut side effects that eased over time. (Lancet, 2026)
In adults with obesity without diabetes, the most common side effects of retatrutide affected the digestive system. (The New England journal of medicine, 2026)
In a pooled analysis of trials, retatrutide did not raise the rate of serious side effects. (Metabolism: clinical and experimental, 2024)
In people with obesity, retatrutide and placebo groups had no significant difference in adverse events across three pooled trials. (Proceedings, 2025)
In people with overweight, obesity or type 2 diabetes, retatrutide was linked to more mild stomach and gut side effects than placebo in pooled trials. (Metabolism open, 2024)
In a pooled analysis of trials, retatrutide had the highest risk of side effects among the drugs compared. (Obesity, 2025)
In adults with obesity and without diabetes, retatrutide had notable stomach and gut side effects, according to a review of studies. (Medicina, 2025)
In a pooled analysis of four trials, the safety of retatrutide was found to be comparable to the control group. (Expert review of clinical pharmacology, 2025)
In a pooled analysis of trials, retatrutide was less well tolerated than mazdutide. (Endocrinology, diabetes & metabolism, 2026)
In adults with obesity, stomach and gut side effects were the side effects most often reported with retatrutide. (Journal of basic and clinical physiology and pharmacology, 2025)
In adults with overweight or obesity, low certainty evidence suggested more people stopped retatrutide. (BMJ medicine, 2026)
In the pooled analysis, retatrutide's side effects were mainly stomach and gut problems. (Maedica, 2025)
A man with type 1 diabetes had severe vomiting after using an online-bought product sold as retatrutide; the cause is uncertain. (Cureus, 2026)
In a phase 1 study of single doses, retatrutide had a safety profile similar to other drugs of its type. (Cell metabolism, 2022)
In adults with type 2 diabetes, stomach and gut problems were the side effects reported most often. (Lancet, 2022)
In adults with obesity and type 2 diabetes, two people died in the retatrutide 4 mg group; the investigator judged the deaths unrelated to treatment. (Lancet, 2026)
In adults with obesity and type 2 diabetes, diarrhoea happened more often with retatrutide 4 mg than with placebo. (Lancet, 2026)
In adults with obesity and type 2 diabetes, nausea happened more often with retatrutide 4 mg than with placebo. (Lancet, 2026)
In adults with obesity and type 2 diabetes, low blood pressure happened more often with retatrutide 4 mg than with placebo. (Lancet, 2026)

See every safety result on the Scientific page

Doses studied (40 shown)

The doses that these studies used. They are not recommendations.

Dose as reported	Class	Species	Route	Duration	Design	Source
12 mg	Human	human	subcutaneous	80 weeks	Randomized trial in people · n = 576	Bellido 2026
9 mg	Human	human	subcutaneous	80 weeks	Randomized trial in people · n = 574	Jastreboff 2026
12 mg	Human	human	subcutaneous	80 weeks	Randomized trial in people · n = 574	Jastreboff 2026
9 mg	Human	human	subcutaneous	80 weeks	Randomized trial in people · n = 573	Bellido 2026
1 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people · n = 98	Sanyal 2024
4 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people · n = 98	Sanyal 2024
8 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people · n = 98	Sanyal 2024
12 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people · n = 98	Sanyal 2024
0.5 mg, 1.5 mg, 3 mg, 3/6 mg and 3/6/9/12 mg once weekly	Human	human	subcutaneous	12 weeks	Randomized trial in people · n = 72	Urva 2022
1 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people	Jastreboff 2023
4 mg once weekly (combined 4-mg group)	Human	human	subcutaneous	48 weeks	Randomized trial in people	Jastreboff 2023
8 mg once weekly (combined 8-mg group)	Human	human	subcutaneous	48 weeks	Randomized trial in people	Jastreboff 2023
12 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people	Jastreboff 2023
0.5 mg once weekly	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
4 mg once weekly (escalation group)	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
4 mg once weekly	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
8 mg once weekly (slow escalation group)	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
8 mg once weekly (fast escalation group)	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
12 mg once weekly (escalation group)	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
4, 8 and 12 mg groups	Human	human	injection	24 weeks	Randomized trial in people	Rosenstock 2023
0.5 mg	Human	human	subcutaneous	36 weeks	Randomized trial in people	Coskun 2025
4 mg (pooled)	Human	human	subcutaneous	36 weeks	Randomized trial in people	Coskun 2025
8 mg (pooled)	Human	human	subcutaneous	36 weeks	Randomized trial in people	Coskun 2025
12 mg	Human	human	subcutaneous	36 weeks	Randomized trial in people	Coskun 2025
4 mg once weekly	Human	human	subcutaneous	40 weeks	Randomized trial in people	Bajaj 2026
9 mg once weekly	Human	human	subcutaneous	40 weeks	Randomized trial in people	Bajaj 2026
12 mg once weekly	Human	human	subcutaneous	40 weeks	Randomized trial in people	Bajaj 2026
4 mg	Human	human	subcutaneous	80 weeks	Randomized trial in people · n = 581	Bellido 2026
4 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people	Jastreboff 2023
8 mg once weekly	Human	human	subcutaneous	48 weeks	Randomized trial in people	Jastreboff 2023
0.5 to 12 mg once weekly	Human	human	injection	36 weeks	Randomized trial in people	Rosenstock 2023
4 mg and higher	Human	human	injection	36 weeks	Randomized trial in people	Rosenstock 2023
3 mg once weekly	Human	human	subcutaneous	12 weeks	Randomized trial in people	Urva 2022
3/6 mg once weekly	Human	human	subcutaneous	12 weeks	Randomized trial in people	Urva 2022
3/6/9/12 mg once weekly	Human	human	subcutaneous	12 weeks	Randomized trial in people	Urva 2022
dose dependent, up to 3/6/9/12 mg once weekly	Human	human	subcutaneous	12 weeks	Randomized trial in people	Urva 2022
1, 4, 8, 12 mg	Human	human	Not reported	36 weeks	Randomized trial in people · n = 282	Pearson 2026
0.5-12 mg	Human	human	Not reported	48 weeks	Randomized trial in people · n = 213	Pearson 2026
higher doses (up to 12 mg)	Human	human	Not reported	36 weeks (obesity trial); 48 weeks (T2D trial)	Randomized trial in people	Pearson 2026
>=4 mg	Human	human	Not reported	24 weeks	Randomized trial in people	Kanu 2025

From the community

How people use it

What people report online. It comes from forums and guides, not from studies.

Community-reported. Not tested in trials.

Retatrutide is an investigational once-weekly triple agonist. Community use is gray-market use of research-chemical vials, mostly alone. Reports copy the trial steps from 1 or 2 mg, or start lower, and range up to 12 mg a week.

Reported routines and cautions

What people use it for

Weight loss and appetite controlS1
Use alone, not stacked with other GLP-1 drugs (most reports)S1

Reported regimens

Regimens that community sources report for Retatrutide. Community-reported, not tested in trials.
Context	Route	Amount	How often	How long	Agreement	Sources
Copying the phase 2 trial steps without supervision	subcutaneous injectionfrom research-chemical vials	1 to 12 mg per dose	once weekly	48 weeks or more	2 sources give a weekly range up to 12 mg (S1: 1 to 12 mg; S2: 0.5 to 12 mg); S2 says use is variable and sometimes irregular; both sources carry seller links	S1S2
Slow start below the trial doses	subcutaneous injection	0.5 to 4 mg per dose	once weekly	12 to 24 weeks	single source; the source carries seller links	S1
Staying at a middle dose	subcutaneous injection	4 to 8 mg per dose	once weekly	ongoing	single source; the source carries seller links	S1

Reported side effects

nauseaS1S3
diarrheaS1
raised resting heart rateS1S3
fatigue, insomnia and food craving (Reddit posts)S3
appetite increase (named most often in Reddit posts)S3

Reported benefits (claims, not shown in trials)

appetite suppression described as stronger than with semaglutide or tirzepatideS1

Cautions

Retatrutide from research-chemical suppliers has not been checked for identity, purity or sterility by regulators.S1
The wiki says most community users have no regular blood work or clinical monitoring. Trial participants had vital signs, lab work, ECG checks and adverse event collection.S1
One guide (outliyr.com) says using retatrutide outside a trial, such as skipping titration, exceeding studied doses or microdosing for speculative reasons, has no human safety data.S2
The authors of a Reddit-based preprint call their findings hypothesis-generating. They say the findings warrant pharmacovigilance attention.S3

Status notes

FDA says retatrutide cannot be used in compounding under federal law. It is not part of any FDA-approved drug and has not been found safe and effective for any condition. FDA has warned telehealth firms, ingredient distributors and outsourcing facilities. FDA page content current as of 2026-10-01.S4
Per a law-firm summary, FDA issued warning letters on 2024-12-17 to five companies that offer GLP-1 products, including retatrutide. FDA determined that these products are unapproved new drugs.S5
A news article dated 2026-08-14 says Eli Lilly sued six US companies it accuses of selling unapproved copies of retatrutide. It says no regulator has approved the drug and it is still in Phase 3 testing.S6

Community sources

S1Retatrutide: Community Protocols & Reportspeptideprotocolwiki.comcarries seller links, not linked
S2Retatrutide: benefits, dosage & risksoutliyr.comcarries seller links, not linked
S3Self-reported side effects among Reddit users taking unapproved retatrutide (preprint) (opens in a new tab)medrxiv.org
S4FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (opens in a new tab)fda.gov
S5FDA targets GLP-1 providers with warning letters (opens in a new tab)foley.com
S6Why is a drugmaker suing six sellers over a drug no one can legally buy? (opens in a new tab)benefitsandpensionsmonitor.com

Gaps

No public forum with checkable per-person posts was found; Reddit cannot be fetched here. The wiki page summarizes Reddit and the Reddit study is a preprint that lists symptoms, not doses. Two dosing sources describe ranges, not who takes what. Vial purity is not known, so stated doses may not match contents. A preprint on gray-market retatrutide use could not be fetched.

Questions and more

Common questions

Is retatrutide the same as GLP-3?

Yes, GLP-3 is listed as another name for retatrutide, and so is GLP-3 RT.¹ Eli Lilly, the developer, calls its phase 3 program for the molecule TRIUMPH.⁵ A search of ClinicalTrials.gov for retatrutide or for the code LY3437943 finds the registered studies of the molecule.^1,5 See what retatrutide is

How much weight did people lose in retatrutide studies?

In a phase 2 trial in adults with obesity, one group lost 7.2% of body weight at 24 weeks, against 1.6% with placebo.¹⁶ A phase 3 trial also found more weight loss than placebo at week 80.⁶ A study in adults with type 2 diabetes found no significant drop in body fat versus placebo in one group at week 36.²⁷ See what retatrutide studies show

Is retatrutide safe?

It is not known.⁷ In a phase 1b trial of 72 adults with type 2 diabetes, 63% of people given retatrutide reported side effects, against 54% with placebo.²⁰ A pooled analysis of trials found no rise in serious side effects.²⁸ The FDA states that retatrutide is not a component of any FDA-approved drug.⁷ See retatrutide side effects and safety

When will retatrutide be approved?

It is not known.^5,7 Eli Lilly plans to submit a US application in early 2027.^5,7 Lilly calls its planned filing a Biologics License Application, while the FDA holds that retatrutide is not a protein or biological product, so a drug application would apply.⁷ 11 of the 34 registered trials that test retatrutide are active or planned.¹² See if retatrutide is approved

What do users report about retatrutide?

Users report using retatrutide for weight loss and appetite control, and most reports describe using it alone rather than with other GLP-1 drugs.²⁹ Reported effects include nausea, diarrhea and a raised resting heart rate.²⁹ Some Reddit posts also name fatigue, insomnia and food craving.²⁹ These are reports from forums and guides, and they have not been tested in trials.²⁹ See how people use it

Ask a question about retatrutide

The answer links to every study it uses.

What does the evidence say about retatrutide?Is retatrutide tested in people?Compare with Semaglutide Compare with Liraglutide

Sources

Database: PepBank profile: identity and structure (GSRS Retatrutide NOP2Y096GV (API); GSRS Retatrutide sodium LQ42M82ZU6 (API); PubChem CID 171934787 properties)
Database: Target record: Gastric inhibitory polypeptide receptor (GIPR)
Database: Target record: Glucagon-like peptide 1 receptor (GLP1R)
Database: Target record: Glucagon receptor (GCGR)
Database: Development record
People: Bellido et al., 2026, Lancet (London, England) (PMID 42810372)
Regulator: FDA (United States) status record, as of 2026-10-09
Regulator: EMA (European Union) status record, as of 2026-10-09
Regulator: WADA Prohibited List 2026
Trial registry: ClinicalTrials.gov NCT03841630: A Safety Study of LY3437943 Given as a Single Injection in Healthy Participants
Trial registry: ClinicalTrials.gov NCT04867785: A Study of LY3437943 in Participants With Type 2 Diabetes
Database: PepBank data for Retatrutide (data version 308541)
Trial registry: ClinicalTrials.gov NCT05929066: A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight
Trial registry: ClinicalTrials.gov NCT05929079: A Study of Retatrutide (LY3437943) in Participants With Type 2 Diabetes Mellitus Who Have Obesity or Overweight
Trial registry: ClinicalTrials.gov NCT06383390: The Effect of Retatrutide Once Weekly on Cardiovascular Outcomes and Kidney Outcomes in Adults Living With Obesity (TRIUMPH-Outcomes)
People: Jastreboff et al., 2023, The New England journal of medicine (PMID 37366315)
Animals: Ma et al., 2025, Endocrine (PMID 39212900)
People: Kanu et al., 2025, Diabetes, obesity & metabolism (PMID 40916752)
People: Bajaj et al., 2026, Lancet (London, England) (PMID 42250575)
People: Urva et al., 2022, Lancet (London, England) (PMID 36354040)
People: Wen et al., 2025, Diabetes, obesity & metabolism (PMID 40726454)
People: Sanyal et al., 2024, Nature medicine (PMID 38858523)
People: Wang et al., 2025, The Journal of clinical endocrinology and metabolism (PMID 40489581)
People: Heerspink et al., 2025, Kidney international reports (PMID 40630318)
People: Abdrabou et al., 2025, Proceedings (Baylor University. Medical Center) (PMID 40291085)
Animals: Takahashi et al., 2026, Nature communications (PMID 42156758)
People: Coskun et al., 2025, The lancet. Diabetes & endocrinology (PMID 40609566)
People: Xie et al., 2024, Metabolism (PMID 39305981)
Community: Community sources (forums and guides), as summarized in the PepBank community file

AI wrote this page from the sources above. AI can make mistakes, so check important facts against the source.

PepBank is a research reference. Talk to a doctor before you use any peptide.

Ask your AI about retatrutide

Curo is a peptide shop. PepBank and Curo have the same owner. See the Curo catalog (opens in a new tab).