The most common retatrutide side effects in clinical trials are gastrointestinal: nausea, diarrhea, constipation and vomiting. In TRIUMPH-1, the largest phase 3 trial so far, nausea affected 28.6% to 42.4% of people on retatrutide (depending on the dose arm) versus 14.8% on placebo. Higher dose arms generally had more stomach side effects, and most were described as mild to moderate.
Two things set retatrutide apart from Ozempic-style drugs. First, a skin-sensation effect called dysesthesia (tingling, burning or unusual skin sensitivity) showed up in up to about 1 in 5 people in one phase 3 arm. Second, heart rate went up in phase 2, then eased later in treatment. Between about 2% and 18% of people stopped retatrutide because of side effects, depending on the trial and dose, compared with 0% to 5% on placebo.
What nobody knows yet: long-term safety beyond about two years, and whether retatrutide reduces or raises heart attack and stroke risk. That question belongs to TRIUMPH-OUTCOMES, which is still running. Retatrutide is not approved anywhere, including Canada.
Retatrutide side effects at a glance
Retatrutide is Eli Lilly’s experimental “triple agonist”. It activates three hormone receptors at once: GIP, GLP-1 and glucagon. If you want the background first, start with What is retatrutide?. This page does one job: it lists every side effect that has shown up in the published trials, with the actual numbers.
For an overall safety verdict, see Is retatrutide safe?.
Here is the quick list, roughly in order of how often each effect showed up:
- Nausea, diarrhea, constipation, vomiting: the big four, each reported by roughly 5% to 43% of people depending on trial and dose arm.
- Decreased appetite: up to about 19% (it is also how the drug works).
- Dysesthesia / skin sensitivity: 2% to 21%, versus about 1% on placebo.
- Heart rate increase: dose-dependent in phase 2, peaking around week 24.
- Rare but serious: gallbladder events and one case of acute pancreatitis in phase 2.
Every side-effect rate on this page comes from supervised clinical trials of Lilly’s pharmaceutical-grade product, in screened volunteers. Retatrutide is not an approved medicine in Canada or anywhere else. If you have symptoms or questions about any weight-loss medicine, talk to your doctor or pharmacist.
Nausea, diarrhea, vomiting and constipation
As with other GLP-1-based drugs, the gut is where most retatrutide side effects show up. Here are the four big gastrointestinal (GI) effects across every trial that has released numbers.
| Trial (length) | Nausea | Diarrhea | Vomiting | Constipation |
|---|---|---|---|---|
| Phase 2 obesity, NEJM 2023 (48 wk), all retatrutide arms pooled | 27% (placebo 11%) | 13% (11%) | 10% (1%) | 9% (3%) |
| TRIUMPH-1, obesity (80 wk), 4 / 9 / 12 mg arms | 28.6 / 38.4 / 42.4% (placebo 14.8%) | 25.2 / 34.1 / 32.0% (13.5%) | 10.6 / 22.8 / 25.3% (4.8%) | 23.8 / 25.9 / 26.1% (10.9%) |
| TRIUMPH-4, obesity + knee arthritis (68 wk), 9 / 12 mg | 38.1 / 43.2% (10.7%) | 34.7 / 33.1% (13.4%) | 20.4 / 20.9% (0.0%) | 21.8 / 25.0% (8.7%) |
| TRIUMPH-2, obesity + type 2 diabetes (80 wk), 4 / 9 / 12 mg | 13.7 / 20.8 / 28.0% (8.0%) | 27.4 / 33.5 / 33.6% (13.2%) | 5.5 / 10.2 / 15.7% (4.2%) | 14.0 / 16.2 / 16.8% (9.4%) |
| TRIUMPH-3, obesity + heart disease (80 wk), 9 / 12 mg | 21.7 / 22.4% (5.8%) | 30.1 / 24.4% (8.7%) | Not reported | 18.0 / 15.7% (7.1%) |
| TRANSCEND-T2D-1, type 2 diabetes (40 wk), 4 / 9 / 12 mg | 16.4 / 19.5 / 26.5% (3.7%) | 18.7 / 26.3 / 22.8% (4.5%) | 15.7 / 15.0 / 17.6% (2.2%) | Not reported |
Sources: Jastreboff 2023; Lilly press releases for TRIUMPH-4 (Dec 2025), TRIUMPH-1 (May 2026) and TRIUMPH-2/3 (July 2026); HCPLive report of TRANSCEND-T2D-1 (ADA, June 2026). Percentages are the share of participants reporting the event at any point in the trial.
What the GI numbers actually mean
A few patterns jump out of that table:
- Nausea is the headline side effect in people without diabetes. In TRIUMPH-1 and TRIUMPH-4, roughly 4 in 10 people in the higher dose arms reported nausea at some point.
- Diarrhea is surprisingly prominent. In TRIUMPH-2 and TRIUMPH-3, diarrhea was reported more often than nausea. That is a slightly different pattern from what many people expect with Ozempic-type drugs.
- People with type 2 diabetes reported less nausea. Nausea rates in TRIUMPH-2 and TRANSCEND-T2D-1 were noticeably lower than in TRIUMPH-1 and TRIUMPH-4, which enrolled people without diabetes.
- Placebo is not zero. 10% to 15% of people on placebo also reported nausea in the obesity trials.
Lilly and the investigators described these GI events as mostly mild to moderate, mostly resolving during treatment and happening mainly while doses were being increased. Still, in phase 2, GI events were the most common reason people stopped treatment.
Decreased appetite
“Decreased appetite” is logged as an adverse event too: 18.2% to 19.0% in TRIUMPH-4 and up to 17.1% in TRIUMPH-2, versus about 3% to 9% on placebo. Appetite suppression is the point, but a big drop can make it hard to eat enough protein, which links to the muscle-loss question below.
How side effects changed with dose and escalation
Here is exactly what the trials showed. These are trial facts only, not advice.
Higher dose arms, more GI effects (mostly)
The phase 3 trials tested fixed target doses of 4, 9 and 12 mg once weekly, depending on the trial. In TRIUMPH-1, nausea rose step by step across the arms: 28.6% at 4 mg, 38.4% at 9 mg and 42.4% at 12 mg. Vomiting more than doubled from the 4 mg arm (10.6%) to the 12 mg arm (25.3%). TRIUMPH-2 showed the same staircase for nausea, vomiting and decreased appetite.
The relationship is not perfectly linear for every symptom. Diarrhea was about the same in the 9 mg and 12 mg arms of TRIUMPH-1, TRIUMPH-2 and TRIUMPH-4, and constipation barely changed between arms. In TRIUMPH-3, diarrhea was actually reported less often at 12 mg (24.4%) than at 9 mg (30.1%).
The starting step mattered in phase 2
In all the trials, doses were increased gradually up to the target over the first weeks of the study, rather than started at full strength. The 2023 phase 2 obesity trial (Jastreboff et al., NEJM) directly compared a lower and a higher starting step for the same target dose, which tells us something useful about tolerability:
| Phase 2 arm (48 weeks) | Nausea | Vomiting | Diarrhea |
|---|---|---|---|
| 8 mg target, lower starting step | 17% | 6% | 20% |
| 8 mg target, higher starting step | 60% | 26% | 20% |
| 4 mg target, lower starting step | 18% | 12% | 12% |
| 4 mg target, higher starting step | 36% | 12% | 12% |
| Placebo | 11% | 1% | 11% |
The authors wrote that GI events occurred mainly during dose escalation, were dose-related, and were “partially mitigated with a lower starting dose.” Nausea showed the clearest difference. Diarrhea did not change at all. The separate phase 2 trial in type 2 diabetes (Rosenstock et al., Lancet 2023) found the same direction: GI events were more frequent in the higher starting-dose groups. That knowledge is why every phase 3 trial used a gradual step-up design.
These describe how regulated trials were designed and what happened in them. They are not a guide to using retatrutide, and TrueLabs does not provide dosing or administration information.
Dysesthesia: the skin-sensation signal
This is the least familiar side effect, and the one that most clearly separates retatrutide from semaglutide and tirzepatide so far.
Dysesthesia is a medical term for abnormal or unpleasant skin sensations: tingling, burning, prickling, or skin that feels unusually sensitive to touch. In the phase 2 trial, investigators called it cutaneous hyperesthesia or skin sensitivity.
How often it happened
| Trial | Retatrutide arms | Placebo |
|---|---|---|
| Phase 2 obesity (2023) | 7% overall; 13% at 12 mg | 1% |
| TRIUMPH-4 (9 / 12 mg) | 8.8% / 20.9% | 0.7% |
| TRIUMPH-1 (4 / 9 / 12 mg) | 5.1% / 12.3% / 12.5% | 0.9% |
| TRIUMPH-2 (4 / 9 / 12 mg) | 4.5% / 5.6% / 7.3% | 0.7% |
| TRIUMPH-3 (9 / 12 mg) | 6.4% / 6.4% | 1.3% |
| TRANSCEND-T2D-1 (4 / 9 / 12 mg) | 4.5% / 2.3% / 4.4% | 0% |
What we know about it
- It was generally mild. In phase 2, none of the cases were severe or serious, none were linked to visible skin changes, and none led to stopping treatment. Lilly described TRIUMPH-4 dysesthesia as “generally mild” and said it rarely led to discontinuation.
- It does not seem to be simply a weight-loss effect. The phase 2 authors wrote that these events “did not appear to be related to the magnitude or rate of weight loss.”
- It was highest where weight loss was highest. The biggest rates (TRIUMPH-4 and TRIUMPH-1) came from trials of people without diabetes, who also lost the most weight. It was lower in the diabetes trials. Why that is remains unexplained in the data released so far.
- The cause is not established. None of the releases we reviewed give a confirmed mechanism.
Heart rate increase
“Retatrutide heart rate” is a big search, and for good reason. A modest rise in resting heart rate is a known effect of GLP-1-based drugs. In one retatrutide trial, the GLP-1 comparator drug dulaglutide raised pulse too.
Here is what the published data actually say:
- Phase 2 obesity trial: heart rate increased in a dose-dependent way. It peaked at 24 weeks and declined after that, with lower readings at weeks 36 and 48. The main paper puts the exact beats-per-minute values in its supplement.
- Phase 2 type 2 diabetes trial: the authors reported “an increase in pulse rate, up to approximately 7 bpm” early in treatment, which decreased by 36 weeks. At week 36, the changes in the retatrutide groups were not significantly different from dulaglutide (a GLP-1 drug, Trulicity), the active comparator.
- Arrhythmias in phase 2 obesity: cardiac arrhythmia events were reported in 6% of retatrutide participants versus 3% on placebo, higher in some high-dose arms. They were mild to moderate, except one severe case of QT prolongation in someone also taking the anti-nausea drug ondansetron.
- Phase 3: the TRIUMPH topline press releases we reviewed did not report heart-rate data. Expect that in the full journal publications.
Dr. Beth Abramson, commenting on the phase 2 results to TCTMD, said, “It remains to be determined whether or not this becomes clinically important.” That is still the honest answer (see What is still unknown).
How many people stopped because of side effects
Discontinuation due to adverse events shows how many people found side effects bad enough to quit.
| Trial | Stopped due to side effects (retatrutide arms) | Placebo |
|---|---|---|
| Phase 2 obesity (48 wk) | 6% to 16% (16% at 12 mg) | 0% |
| TRIUMPH-1 (80 wk), 4 / 9 / 12 mg | 4.1% / 6.9% / 11.3% | 4.9% |
| TRIUMPH-4 (68 wk), 9 / 12 mg | 12.2% / 18.2% | 4.0% |
| TRIUMPH-2 (80 wk), 4 / 9 / 12 mg | 3.8% / 11.6% / 7.7% | 4.9% |
| TRIUMPH-3 (80 wk), 9 / 12 mg | 9.8% / 13.5% | 4.8% |
| TRANSCEND-T2D-1 (40 wk), 4 / 9 / 12 mg | 2.2% / 4.5% / 5.1% | 0% |
Two details are worth knowing. First, the lowest dose arm (4 mg) had discontinuation rates close to placebo in both TRIUMPH-1 and TRIUMPH-2. Second, Lilly said TRIUMPH-4 discontinuations were linked to baseline BMI, and some were due to perceived excessive weight loss. Among participants starting with a BMI of 35 or more, discontinuation was lower: 8.8% at 9 mg and 12.1% at 12 mg.
Gallbladder and pancreatitis
Gallbladder and pancreas events are watched closely with every GLP-1-based drug, and rapid weight loss is itself linked to gallstones. So these are fair questions for a drug producing 25% to 30% average weight loss in some arms.
- Gallbladder (phase 2): three participants (1%) had biliary events, one with cholecystitis (gallbladder inflammation) and two with gallstones. All three were in the 8 mg arms.
- Pancreatitis (phase 2): one serious case of acute pancreatitis (under 1%), in the 12 mg arm. Other rises in pancreatic enzymes (amylase, lipase) caused no symptoms.
- Phase 3: the topline releases did not break out gallbladder or pancreatitis rates. The full papers will be important here, because events this rare need thousands of participants to estimate properly.
For context, semaglutide’s STEP 1 trial reported gallbladder-related disorders in 2.6% of people versus 1.2% on placebo, and acute pancreatitis in 0.2% versus 0%. Tirzepatide’s SURMOUNT-1 trial reported adjudicated pancreatitis in 0.2% of every group, placebo included.
Also from phase 2: no clinically significant low blood sugar, no medullary thyroid cancer or C-cell hyperplasia, and liver enzymes that stayed stable or fell on average by week 48.
Hair loss, muscle loss and mood
Does retatrutide cause hair loss?
Hair loss was not listed among the common side effects in any retatrutide release or paper we reviewed. That does not mean it cannot happen. Hair shedding is commonly reported after rapid weight loss, and it showed up in tirzepatide’s main obesity trial. In SURMOUNT-1, alopecia was reported in 4.9% to 5.7% of people on tirzepatide versus 0.9% on placebo. With larger weight loss, it would be surprising if retatrutide were completely free of it. The full phase 3 safety tables will tell us. For more on the mechanism, see Hair loss on Ozempic.
Does retatrutide cause muscle loss?
All major weight loss includes some lean mass, not just fat. The best retatrutide data so far come from a phase 2 body-composition sub-study (DXA scans) in people with type 2 diabetes, published in Lancet Diabetes & Endocrinology in 2025. Total fat mass fell by 26.1% in the 8 mg group and 23.2% in the 12 mg group at 36 weeks, versus 4.5% on placebo. The investigators concluded that the weight loss “does not come at the cost of disproportionately losing lean mass.” That is reassuring but limited: 189 people, 36 weeks. Our guide on muscle loss on GLP-1 drugs explains why protein intake and resistance training matter for anyone on these medicines.
Mood, depression and anxiety
None of the retatrutide trial readouts we reviewed flagged mood or psychiatric side effects as a signal. For the wider GLP-1 class, the European Medicines Agency’s safety committee (PRAC) reviewed suicidal thoughts in April 2024. It concluded that “the available evidence does not support a causal association” for dulaglutide, exenatide, liraglutide, lixisenatide and semaglutide. Retatrutide was not part of that review, so it has no equivalent verdict yet. If you notice changes in mood on any medication, tell your doctor.
Retatrutide side effects in women
Here is what the evidence does and does not show for women.
- Women lost more weight in phase 2. An analysis presented at ObesityWeek 2023 found that women had a 4.2-percentage-point greater placebo-adjusted weight reduction than men. In the 8 mg arm, the mean maximum was 28.5% for women versus up to 21.9% for men.
- No sex-specific side-effect breakdown has been published that we could find. The trial readouts report side effects for everyone together, so any claim that women get more (or fewer) retatrutide side effects is not backed by published data yet.
- No pregnancy or breastfeeding data. None of the readouts we reviewed contain data in pregnancy. For approved GLP-1 medicines, contraception and pregnancy planning are a standard conversation with your prescriber.
Your doctor or pharmacist can walk you through sex-specific considerations such as contraception, PCOS and menopause. Related: PCOS treatment in Canada.
Retatrutide vs semaglutide vs tirzepatide side effects
This table compares each drug’s flagship obesity trial. They are different trials, with different lengths, populations and placebo rates, so treat this as a rough guide, not a head-to-head result. For a full comparison including effectiveness, see Retatrutide vs tirzepatide vs semaglutide.
| Semaglutide 2.4 mg (STEP 1, 68 wk) | Tirzepatide 5 / 10 / 15 mg (SURMOUNT-1, 72 wk) | Retatrutide 4 / 9 / 12 mg (TRIUMPH-1, 80 wk) | |
|---|---|---|---|
| Receptors | GLP-1 | GIP + GLP-1 | GIP + GLP-1 + glucagon |
| Average weight loss | 14.9% (placebo 2.4%) | 15.0% to 20.9% (3.1%) | 19.0% to 28.3% (2.2%) |
| Nausea | 44.2% (17.4%) | 24.6% to 33.3% (9.5%) | 28.6% to 42.4% (14.8%) |
| Diarrhea | 31.5% (15.9%) | 18.7% to 23.0% (7.3%) | 25.2% to 34.1% (13.5%) |
| Vomiting | 24.8% (6.6%) | 8.3% to 12.2% (1.7%) | 10.6% to 25.3% (4.8%) |
| Constipation | 23.4% (9.5%) | 11.7% to 17.1% (5.8%) | 23.8% to 26.1% (10.9%) |
| Dysesthesia | Not among reported common events | Not among reported common events | 5.1% to 12.5% (0.9%) |
| Hair loss | Not in main paper | Alopecia 4.9% to 5.7% (0.9%) | Not yet reported |
| Stopped due to side effects | 7.0% (3.1%) | 4.3% to 7.1% (2.6%) | 4.1% to 11.3% (4.9%) |
Placebo rates in brackets. Weight loss figures use each trial’s primary published analysis (STEP 1: treatment-policy estimand; SURMOUNT-1: treatment-regimen estimand; TRIUMPH-1: efficacy estimand), which also limits direct comparison.
The takeaway: retatrutide’s stomach side effects sit in semaglutide’s range and somewhat above tirzepatide’s at top doses, with larger weight loss than either. The new item is dysesthesia; the open question is heart rate. Our tirzepatide side effects guide covers that drug in the same symptom-by-symptom format.
What is still unknown
Retatrutide has a large trial program behind it. Lilly says the TRIUMPH program alone enrolled more than 5,800 people. Still, several important gaps remain:
- Cardiovascular outcomes. TRIUMPH-3 enrolled people with established heart disease. Major cardiovascular events “occurred less frequently than anticipated” in both groups, according to Lilly. The hazard ratio for the broad MACE-5 outcome was 0.82 (95% CI 0.55 to 1.22). For the classic MACE-3 outcome (cardiovascular death, heart attack, stroke) it was 1.12 (95% CI 0.64 to 1.96). Both confidence intervals cross 1, so the trial cannot tell us whether retatrutide lowers, raises or does not change heart risk.
- TRIUMPH-OUTCOMES. This dedicated trial (NCT06383390) is designed to answer that question. It is testing whether retatrutide reduces serious heart events and kidney decline in adults aged 45+ with obesity and cardiovascular or kidney disease. It is expected to run about five years and is still recruiting, according to a participating site.
- Long-term safety. The longest data so far run 104 weeks (the TRIUMPH-1 extension). Nothing is known about five or ten years of use.
- Full phase 3 safety tables. Most phase 3 numbers on this page come from press releases and conference presentations. Peer-reviewed papers with complete tables (gallbladder, pancreatitis, heart rate, hair loss, psychiatric events) are still to come.
- The dysesthesia mechanism and how long it lasts.
Lilly plans to submit retatrutide for U.S. approval in Q1 2027; Is retatrutide approved? tracks the timeline, and Retatrutide phase 3 results covers efficacy.
Retatrutide side effect myths
“Myth: Retatrutide has fewer side effects than Ozempic.”
The data do not support that. Retatrutide’s top-dose nausea and vomiting rates are in the same range as semaglutide’s, and it adds dysesthesia. “Stronger” is not the same as “gentler”.
“Myth: The tingling skin means it’s burning fat.”
No evidence supports this. The phase 2 investigators specifically noted that skin-sensitivity events did not appear related to how much or how fast people lost weight. The cause is not yet known.
“Myth: Retatrutide is proven safe for your heart.”
It isn’t proven either way. TRIUMPH-3 showed big improvements in blood pressure, triglycerides and inflammation markers, but the actual heart-event results were inconclusive. The cardiovascular outcomes trial is still running.
“Myth: Trial safety data apply to anything sold online as retatrutide.”
The trials used Lilly’s quality-controlled product under medical supervision. Health Canada’s April 2026 advisory names retatrutide among unauthorized peptide drugs that have not been assessed for safety, efficacy or quality. See Retatrutide in Canada.
For researchers
TrueLabs supplies RT3 (Retatrutide) from $90, strictly for in vitro and laboratory research. It is not for human or veterinary use, and nothing on this page describes how to use it. To check identity and purity against the lot’s certificate of analysis before an experiment, see How to read a peptide COA and the COA library. Researchers comparing incretin pharmacology may also be interested in TZ-2 (Tirzepatide) from $73 and Cagrilintide from $40.
FAQ
Tap a question to reveal the answer.
What are the most common side effects of retatrutide?
In clinical trials, the most common side effects were nausea, diarrhea, constipation, vomiting and decreased appetite. In the 80-week TRIUMPH-1 trial, nausea affected 28.6% to 42.4% of people on retatrutide versus 14.8% on placebo. Most of these effects were described as mild to moderate and happened mainly while doses were being increased.
How common is nausea on retatrutide?
It depends on the trial and dose arm. Nausea ranged from about 14% in the lowest dose arm of TRIUMPH-2 (people with type 2 diabetes) to 43.2% in the highest dose arm of TRIUMPH-4. Placebo rates were roughly 4% to 15%.
Does retatrutide raise your heart rate?
Yes, in phase 2 trials heart rate rose in a dose-dependent way. In the type 2 diabetes trial, the increase was up to about 7 beats per minute early on, then decreased by week 36. In the obesity trial it peaked at 24 weeks and then declined. Whether this matters clinically is not yet known.
What is dysesthesia on retatrutide?
Dysesthesia means abnormal skin sensations such as tingling, burning or unusual sensitivity to touch. It was reported in roughly 2% to 21% of retatrutide participants across trials, versus about 1% on placebo. It was generally mild and rarely led to stopping treatment, and its cause is not yet known.
How many people stopped retatrutide because of side effects?
In phase 3 trials, discontinuation due to adverse events ranged from 2.2% in the lowest dose arm of TRANSCEND-T2D-1 to 18.2% in the highest dose arm of TRIUMPH-4. Placebo rates were 0% to 5%. In TRIUMPH-4, some people stopped because of perceived excessive weight loss.
Does retatrutide cause hair loss?
Hair loss has not been listed among the common side effects in the retatrutide trial data released so far. Hair shedding is known to follow rapid weight loss, and alopecia was reported in about 5% of people on tirzepatide in SURMOUNT-1. Full phase 3 safety tables for retatrutide are still to be published.
Does retatrutide cause gallbladder problems or pancreatitis?
In the phase 2 obesity trial, 1% of retatrutide participants had gallbladder events (inflammation or gallstones), and there was one serious case of acute pancreatitis. Phase 3 rates have not been broken out in the topline releases. These are known risks of the GLP-1 drug class and of rapid weight loss generally.
Are retatrutide side effects different for women?
No sex-specific side-effect data have been published that we could find. In phase 2, women lost more weight than men on average. There are no data on retatrutide in pregnancy or breastfeeding. Women considering any weight-loss medicine should discuss contraception and pregnancy plans with their doctor.
Is retatrutide worse than Ozempic or Mounjaro for side effects?
Comparing separate trials, retatrutide’s stomach side effects are roughly similar to semaglutide (Ozempic, Wegovy) and somewhat higher than tirzepatide (Mounjaro, Zepbound) at top doses, plus a dysesthesia signal. No head-to-head side-effect trial has been published.
Related reading
- What Is Retatrutide? The Triple-G Agonist Explained
- Is Retatrutide Safe? What the Evidence Shows
- Retatrutide Phase 3 Results
- Retatrutide vs Tirzepatide vs Semaglutide
- Tirzepatide Side Effects
- Retatrutide in Canada
References
- Jastreboff AM, Kaplan LM, Frías JP, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023. doi:10.1056/NEJMoa2301972. PubMed
- Rosenstock J, Frias J, Jastreboff AM, et al. 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. Lancet. 2023. doi:10.1016/S0140-6736(23)01053-X. PubMed
- Eli Lilly and Company. Press release on topline TRIUMPH-4 results for retatrutide in obesity and knee osteoarthritis. December 11, 2025. Lilly
- Eli Lilly and Company. Lilly’s triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial (TRIUMPH-1). Press release, May 21, 2026. Lilly
- Eli Lilly and Company. Lilly’s triple agonist retatrutide successful in two additional Phase 3 obesity trials, delivering significant improvements in weight and A1C (TRIUMPH-2, TRIUMPH-3). Press release, July 23, 2026. BioSpace
- HCPLive. TRANSCEND-T2D-1: Retatrutide demonstrates superior weight loss and A1c results versus placebo. June 6, 2026. HCPLive
- Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021. doi:10.1056/NEJMoa2032183. PubMed
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387(3). doi:10.1056/NEJMoa2206038. PubMed
- MIMS. Investigational triple–hormone-receptor agonist reduces fat mass in people with T2D (report on body-composition sub-study, Lancet Diabetes Endocrinol 2025; doi:10.1016/S2213-8587(25)00092-0). July 10, 2025. MIMS
- Healio. Weight loss varies with investigational triple agonist for adults with obesity (ObesityWeek 2023 sub-analysis). Healio
- TCTMD. Dramatic weight loss, cardiometabolic improvement with retatrutide. June 28, 2023. TCTMD
- European Medicines Agency. Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC), 8–11 April 2024. EMA
- The Effect of Retatrutide Once Weekly on Cardiovascular Outcomes and Kidney Outcomes in Adults Living With Obesity (TRIUMPH-OUTCOMES). NCT06383390. ClinicalTrials.gov
- Health Canada. Think twice before injecting peptides bought online: unauthorized products can seriously harm your health. Advisory RA-81874, April 9, 2026. Health Canada
This article summarizes published research and regulatory information for information only and is not medical advice. TrueLabs research compounds are sold for in vitro and laboratory research use only and are not intended for human or veterinary use.