Tirzepatide acts on the GIP and GLP-1 receptors and is approved in the US and EU for type 2 diabetes and weight management. Retatrutide also acts on the glucagon receptor, and it is in phase 3 trials and not approved. This page compares their study results.
Comparing 2 peptides · Data version 308560
Swipe sideways to see every peptide.
| Peptide | Synthetic analog Tirzepatide | Synthetic analog Retatrutide |
|---|---|---|
| Identity | ||
| Kind | Synthetic analog | Synthetic analog |
| Area | Weight and metabolic | Weight and metabolic |
| Evidence | ||
| Amount of evidence | 2,165 | 380 |
| Evidence level | Has results from studies in people | Has results from studies in people |
| Safety | ||
| Safety results | 462 (462 in people) | 61 (61 in people) |
| Status | ||
| Approval | ||
| Sport (WADA) | ||
| Registered trials | 254 · 162 active47 more mention it but do not test it | 34 · 11 active |
Shared outcomes
From the regulatory data of each peptide.
The FDA label for Mounjaro says: “Adjunct to diet and exercise for glycemic control in adults and pediatric patients 10 years and older with type 2 diabetes; reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes at high risk for these events”
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).
Outcome groups with study results for at least two of these peptides. Counts include only results from studies that gave the peptide. Bar length is the number of results, on one scale. The bars show how much was studied, not how large an effect was. A peptide with more studies can look stronger here without being stronger. For results, see the randomized results above.
| Outcome group | Tirzepatide | Retatrutide |
|---|---|---|
| Body weightMetabolic and weight | 521501182 | 987919 |
| Glycemic controlMetabolic and weight | 36435581 | 32266 |
| Adverse eventsWhole body | 213213 | 3838 |
| Gastrointestinal adverse eventsGastrointestinal | 179179 | 1717 |
| LipidsMetabolic and weight | 79763 | 271611 |
| Liver fat and liver functionLiver | 5353 | 20137 |
| MortalityWhole body | 635724 | 66 |
| Blood pressureCardiovascular | 5151 | 44 |
| Kidney functionKidney and urinary | 40391 | 1495 |
| Heart functionCardiovascular | 49427 | 8215 |
| Inflammation markersReproductive and sexual health | 41347 | 14410 |
| Appetite and food intakeMetabolic and weight | 20191 | 19136 |
PepBank is a research reference. Talk to a doctor before you use any peptide.
For each outcome that two or more peptides have results for: the best result of a single randomized trial, on the same measure (the same kind of number, the same unit). When a trial has several dose arms, the cell shows the highest dose arm. The trials differ in people, length and dose, so a gap between two cells is not proof that one peptide works better.
| Outcome | Tirzepatide | Retatrutide |
|---|---|---|
| Body weightMetabolic and weightCompared as: value in the arm that got the peptide, in % | −20.9% Mean percentage weight reduction at week 72 · Shown as a change. The study reports a mean percentage weight reduction at week 72 of this size. · tirzepatide 15 mg Placebo: −3.1% Dose studied: 5 mg, 10 mg or 15 mg once weekly72 weeks, including a 20-week dose-escalation periodn = 2,5392022 | −23.7% Percent change in body weight · retatrutide 9 mg Placebo: −3.9% Dose studied: 9 mg80 weeksn not reported2026 |
| Glycemic controlMetabolic and weightCompared as: value in the arm that got the peptide, in % | −2.3% HbA1c change · tirzepatide 5 mg Dose studied: 5 mg104 weeksn = 1,5002025 | −1.69% HbA1c change · retatrutide 4 mg Dose studied: 4 mg once weekly40 weeksn not reported2026 |
| PharmacokineticsPharmacologyCompared as: value in the arm that got the peptide, in days | ≈ 5 days Half-life Dose studied: 5, 10 or 15 mg8 weeksn = 482022 | ≈ 6 days Half-life · LY3437943 Dose studied: 0.5 mg, 1.5 mg, 3 mg, 3/6 mg and 3/6/9/12 mg once weekly12 weeksn not reported2022 |
| Kidney functionKidney and urinaryCompared as: value in the arm that got the peptide, in % | −19.3% UACR percent change · tirzepatide 5 mg Dose studied: 5 mgweek 40/42n not reported2025 | −37% UACR difference vs placebo · retatrutide 12 mg, T2D, week 36 Dose studied: 12 mg36 weeksn not reported2025 |
| Gastrointestinal adverse eventsGastrointestinalCompared as: share of people in the arm that got the peptide, in % | 15 to 17% Diarrhoea incidence Dose studied: 5 mg, 10 mg or 15 mg once weekly (start 2·5 mg, escalated by 2·5 mg every 4 weeks)52 weeksn = 1,4372021 | 27% Participants with diarrhoea · retatrutide 4 mg Placebo: 13% Dose studied: 4 mgn = 5792026 |
| Adverse eventsMetabolic and weightCompared as: value in the arm that got the peptide, in % | 6.3% discontinuation due to adverse events Placebo: 1.4% Dose studied: up to 15 mg once weeklyat least 52 weeksn = 7312025 | 4% Permanent discontinuation · retatrutide 4 mg Placebo: 5% Dose studied: 4 mgn = 5812026 |
−20.9%
Mean percentage weight reduction at week 72 · Shown as a change. The study reports a mean percentage weight reduction at week 72 of this size. · tirzepatide 15 mg
Placebo: −3.1%
Dose studied: 5 mg, 10 mg or 15 mg once weekly72 weeks, including a 20-week dose-escalation periodn = 2,5392022
−23.7%
Percent change in body weight · retatrutide 9 mg
Placebo: −3.9%
Dose studied: 9 mg80 weeksn not reported2026
−2.3%
HbA1c change · tirzepatide 5 mg
Dose studied: 5 mg104 weeksn = 1,5002025
−1.69%
HbA1c change · retatrutide 4 mg
Dose studied: 4 mg once weekly40 weeksn not reported2026
≈ 5 days
Half-life
Dose studied: 5, 10 or 15 mg8 weeksn = 482022
≈ 6 days
Half-life · LY3437943
Dose studied: 0.5 mg, 1.5 mg, 3 mg, 3/6 mg and 3/6/9/12 mg once weekly12 weeksn not reported2022
−19.3%
UACR percent change · tirzepatide 5 mg
Dose studied: 5 mgweek 40/42n not reported2025
−37%
UACR difference vs placebo · retatrutide 12 mg, T2D, week 36
Dose studied: 12 mg36 weeksn not reported2025
15 to 17%
Diarrhoea incidence
Dose studied: 5 mg, 10 mg or 15 mg once weekly (start 2·5 mg, escalated by 2·5 mg every 4 weeks)52 weeksn = 1,4372021
27%
Participants with diarrhoea · retatrutide 4 mg
Placebo: 13%
Dose studied: 4 mgn = 5792026
6.3%
discontinuation due to adverse events
Placebo: 1.4%
Dose studied: up to 15 mg once weeklyat least 52 weeksn = 7312025
4%
Permanent discontinuation · retatrutide 4 mg
Placebo: 5%
Dose studied: 4 mgn = 5812026
The other peptides have no randomized result on the same measure, so these results cannot be set side by side.
| Outcome | Tirzepatide | Retatrutide |
|---|---|---|
| Metabolic pathways and metabolomicsMetabolic and weightCompared as: value in the arm that got the peptide, in mg/dl | −0.69 mg/dL SUA change · tirzepatide 5 mg Placebo: −0.18 mg/dL Dose studied: 5 mg72 weeksn = 2,5392026 | No comparable result 2 randomized-trial results measure it in another way or another unit. |
| Heart functionCardiovascularCompared as: difference from placebo, in points | 6.9 points between-group difference Dose studied: up to 15 mg once weeklyat least 52 weeksn = 7312025 | No comparable result 1 randomized-trial result measure it in another way or another unit. |
| SleepSleepCompared as: value in the arm that got the peptide, in events/hour | No comparable result 18 randomized-trial results measure it in another way or another unit. | −34.3 events/hour Apnea-hypopnea index change · retatrutide 9 mg, hybrid estimand Placebo, hybrid estimand: −9.9 events/hour Dose studied: 9 mg80 weeksn = 2432026 |
| Appetite and food intakeMetabolic and weightCompared as: difference from placebo, in kcal | −524.6 kcal Estimated treatment difference n not reported2025 | No comparable result 10 randomized-trial results measure it in another way or another unit. |
| LipidsMetabolic and weightCompared as: value in the arm that got the peptide, in % | ≤ 22.9% Variability in triglyceride change explained by apoC-III change Dose studied: 1, 5, 10 or 15 mg once weekly26 weeksn not reported2020 | No comparable result 11 randomized-trial results measure it in another way or another unit. |
| Bone and jointMusculoskeletalCompared as: value in the arm that got the peptide, in % | 33.5% ACR50 Dose studied: US-approved dosesn = 2712026 | No randomized trial result 1 result from other study designs. |
−0.69 mg/dL
SUA change · tirzepatide 5 mg
Placebo: −0.18 mg/dL
Dose studied: 5 mg72 weeksn = 2,5392026
No comparable result
2 randomized-trial results measure it in another way or another unit.
6.9 points
between-group difference
Dose studied: up to 15 mg once weeklyat least 52 weeksn = 7312025
No comparable result
1 randomized-trial result measure it in another way or another unit.
No comparable result
18 randomized-trial results measure it in another way or another unit.
−34.3 events/hour
Apnea-hypopnea index change · retatrutide 9 mg, hybrid estimand
Placebo, hybrid estimand: −9.9 events/hour
Dose studied: 9 mg80 weeksn = 2432026
−524.6 kcal
Estimated treatment difference
n not reported2025
No comparable result
10 randomized-trial results measure it in another way or another unit.
≤ 22.9%
Variability in triglyceride change explained by apoC-III change
Dose studied: 1, 5, 10 or 15 mg once weekly26 weeksn not reported2020
No comparable result
11 randomized-trial results measure it in another way or another unit.
33.5%
ACR50
Dose studied: US-approved dosesn = 2712026
No randomized trial result
1 result from other study designs.
Each analog against its native parent, residue by residue. Substitutions, non-standard residues and modifications are marked. Calculated from the two sequences.
Tirzepatide differs from Gastric inhibitory polypeptide (GIP) at 11 positions and in 1 end segment.
What is different
Retatrutide differs from Gastric inhibitory polypeptide (GIP) at 15 positions and in 1 end segment.
What is different
Registered trials, ranked by phase (late phases first), then posted results and enrollment. Status is the registry status. Study results come from published studies. Results posted at ClinicalTrials.gov are shown on each trial page.
Top 3 of 254 trials, ranked by phase, then posted results and enrollment: 3 completed · 3 with posted results · source ClinicalTrials.gov (opens in a new tab)
Eli Lilly and Company13,299 participants29 May 2020 to 12 Jun 2025
Type 2 Diabetes Mellitus
Eli Lilly and Company2,539 participants4 Dec 2019 to 6 Jul 2024
Overweight · Obesity
Eli Lilly and Company2,002 participants20 Nov 2018 to 22 Apr 2021
Type 2 Diabetes Mellitus
47 more mention it but do not test it. They only measure it or name it in their text.
Top 3 of 34 trials, ranked by phase, then posted results and enrollment: 2 ongoing · 1 completed · source ClinicalTrials.gov (opens in a new tab)
Eli Lilly and Company10,000 participants30 Apr 2024 to est. Feb 2029
Atherosclerotic Cardiovascular Disease (ASCVD) · Chronic Kidney Disease (CKD)
Eli Lilly and Company4,500 participants15 Oct 2025 to est. Aug 2032
Metabolic Dysfunction-Associated Steatotic Liver Disease
Eli Lilly and Company2,335 participants10 Jul 2023 to 30 Apr 2026
Obesity · Overweight · Osteoarthritis, Knee · Obstructive Sleep Apnea
In PepBank now:147 peptides, 6 blends and 13 other compounds97,577 study results from 17,383 studies8,473 clinical trialsUpdated