Eloralintide vs Retatrutide: Which Is Better for Weight Loss?
For weight loss, is eloralintide or retatrutide the better bet?
On weight loss they tie, and neither is a drug you can legitimately buy. Both score 7.5/10 for body composition, and both are investigational Lilly molecules with phase 2 data and no approval. Pick eloralintide if incretin nausea stopped you before, retatrutide if you also have diabetes or fatty liver.
- Body composition is an exact tie at 7.5/10 each, so weight loss alone does not separate them.
- Overall scores are 0.3 apart, retatrutide 5.6/10 to eloralintide 5.3/10, which is inside the noise.
- Eloralintide lost 20.1% of body weight at 48 weeks against 0.4% on placebo in 263 adults. Retatrutide reached up to 24.2% at 48 weeks. Neither trial had plateaued.
- Retatrutide wins everything outside weight: blood sugar 8.0/10 to 2.5/10, liver 8.0/10 to 2.5/10, cardiovascular 6.0/10 to 3.0/10. Eloralintide's phase 2 trial excluded diabetics and measured no liver endpoint.
- Eloralintide is an amylin drug, not an incretin, so the thyroid tumor and pancreatitis warnings that follow the GLP-1 class do not automatically apply to it. Only 2.9% quit for a side effect, against 3.8% on placebo.
- Neither has a pharmacy. Eloralintide is an estimated $432 to $540 a month of research powder, retatrutide an estimated $130 to $960. The only legitimate route to either is a Lilly trial.
- Eloralintide has no human body-composition measurement at all, so nobody has published how much of that 20.1% was muscle.
At a Glance
Eloralintide (LY3841136)
- Efficacy Exceptional
- Breadth Moderate
- Evidence Moderate
- Speed Strong
- Durability Limited
- Bioindividuality Strong
- Safety Risk Moderate
- Side Effects Moderate
- Cost premium Moderate
- Effort Low
- Opportunity Cost Moderate
- Dependency High
- Reversibility Low
- Body Composition
- Metabolic Health
- Cardiovascular
- Blood Sugar
Investigational selective amylin receptor agonist, Lilly LY3841136. BioHarmony 5.0–5.5/10, neutral.
Retatrutide
- Efficacy Exceptional
- Breadth Strong
- Evidence Moderate
- Speed Strong
- Durability Limited
- Bioindividuality Exceptional
- Safety Risk High
- Side Effects Moderate
- Cost premium Low
- Effort Low
- Opportunity Cost Low
- Dependency High
- Reversibility Low
- Metabolic Health
- Liver & Detox
- Blood Sugar
- Body Composition
Investigational GLP-1, GIP and glucagon triple agonist. BioHarmony 5.5–6.0/10, neutral.
Head-to-Head Verdict
| Use Case | Winner | Rationale |
|---|---|---|
| Body Composition | Tie | An exact tie at 7.5/10. Eloralintide cut body weight 20.1% at 48 weeks against 0.4% on placebo (Billings 2025); retatrutide reached up to 24.2% over the same window (Jastreboff 2023). Both carry the same discount, one Lilly-funded phase 2 trial each. Eloralintide adds a limit retatrutide's report does not: no human body-composition measurement exists, so its fat-to-lean split is unmeasured. |
| Metabolic Health | Retatrutide | Retatrutide, 8.5/10 against 5.5/10, and the gap is published numbers rather than biology. Jastreboff 2023 and Rosenstock 2023 report the shifts in appetite, glucose, waist and cardiometabolic markers. Lilly said eloralintide improved the same markers, then released no table, no confidence intervals and no placebo comparison. A sponsor's qualitative claim is not a result. |
| Blood Sugar | Retatrutide | Retatrutide, 8.0/10 against 2.5/10, the widest gap on the page. Rosenstock 2023 reported HbA1c reductions up to 2.02% in type 2 diabetes. Eloralintide's pivotal trial excluded diabetics by design, so it has no HbA1c figure. Amylin damps post-meal glucose in normal physiology, so an effect is expected and ENLIGHTEN-2 will test it in 1,035 people. Until then that is an expectation, not a score. |
| Liver & Detox | Retatrutide | Retatrutide, 8.0/10 against 2.5/10, on a mechanism built for the job. Its glucagon arm raises hepatic fat oxidation, and Sanyal 2024 measured large liver-fat reductions in MASLD directly. Eloralintide has no liver imaging, no fat fraction and no MASLD endpoint anywhere. Liver fat usually falls with weight loss this large, so a benefit is likely and unmeasured. |
| Cardiovascular | Retatrutide | Retatrutide, 6.0/10 against 3.0/10, and neither has an outcomes trial. Eloralintide carries an unexplained signal the other way: a slow-heart-rate term in 11% of the 6 mg group and none on placebo (NCT06230523), plus a published argument that this class may switch on the renin-angiotensin system (Muskiet 2026). Retatrutide's heart-rate effect is a dose-related rise. |
| Healthspan | Retatrutide | Retatrutide, 4.5/10 against 2.5/10, and both numbers are low for the same reason. Neither drug has a morbidity, mortality, cancer, dementia or frailty outcome. Retatrutide is ahead only because more of the intermediate work has been published. Treat any healthspan benefit from either as the ordinary downstream effect of losing a fifth of body weight rather than anything the molecule does directly. |
| Bone & Joint | Retatrutide | Retatrutide, 4.5/10 against 2.0/10, on a topline nobody has peer reviewed. Lilly's TRIUMPH-4 release reported WOMAC pain improvement in knee osteoarthritis. Eloralintide has a knee trial recruiting, no data either way, and an open question about calcitonin-receptor activity and bone. Neither is a joint therapy. |
| Sleep Quality | Tie | Honest tie at 3.5/10 against 2.0/10, because neither has a sleep endpoint. Retatrutide's edge is the general expectation that weight loss eases sleep apnea, set against nausea and dysesthesia disturbing it. Eloralintide has a sleep apnea trial recruiting and no result. If apnea is why you are here, an approved drug already carries that indication. |
| Muscle Growth | Tie | Eloralintide 2.0/10, retatrutide 1.0/10, both at the floor. Neither builds muscle, so the question is what each costs you, and only one has been measured. Retatrutide takes lean mass with fat unless training and protein are managed. Eloralintide's posted outcome list has no body-composition measure at all. Rat work called its loss mostly fat (Briere 2025), which is not a human finding. |
Cost Comparison
| Intervention | Monthly Cost | Notes |
|---|---|---|
| Eloralintide | $432 to $540 | Estimated, September 2026 prices, research-chemical channel. The report says plainly there is no legitimate channel to price. Powder runs about $12 per mg, so 9 mg weekly is 36 to 39 mg a month, $432 to $468, and above $450 all-in with syringes, water and testing.The one route that costs nothing is a phase 3 trial such as ENLIGHTEN-1, recruiting 1,980 people and supplying the drug. |
| Retatrutide | $130 to $960 | Estimated, September 2026 prices, research-chemical channel. Research-peptide 10 mg vials run about $80 to $200. At 4 mg weekly, 16 mg a month, that is $128 to $320. At 12 mg weekly, 48 mg a month, it is $384 to $960. No legal pharmacy channel exists, so this is the price of a vial labeled not for human use, with vendor-dependent purity on top. |
| The difference | Both are unpriceable in any legitimate sense | At their effective doses the two land in the same band, an estimated $432 to $540 for eloralintide against $384 to $960 for retatrutide at 12 mg. Retatrutide is cheaper at a starting dose and more expensive at the one that produced its headline number.Neither figure is a price you can pay at a pharmacy, because neither drug has one. Both are the cost of powder sold not for human use, where identity, concentration and sterility depend entirely on the vendor. The only supply either molecule has that comes with a label, a titration and laboratory monitoring is a Lilly trial, and that one is free. |
When to Switch
There is no switching protocol here: neither drug has a legitimate supply to switch between, and both read out in 2028. Neither trial had plateaued at 48 weeks, so judging either takes about a year. Do not run them together, a pairing with no human data that stacks two sets of gastrointestinal and heart-rate effects. Want amylin today? Pramlintide. Want incretin? Tirzepatide.
Who Should Pick What?
Wants to lose weight and start this month
Tie
Neither. Both are investigational, both are unapproved everywhere, and neither can be prescribed or compounded. Whatever you buy online is powder sold not for human use. An approved incretin does about the same job with years of published exposure behind it, and both source reports point there.
Stopped an incretin drug because of nausea or food aversion
Eloralintide (LY3841136)
The one profile where eloralintide is clearly the better bet, and it is a bet on a trial slot rather than a purchase. It works through the amylin receptor instead of GLP-1, the mechanism most likely to avoid that side effect, and the trial bears it out: 2.9% quit for an adverse event against 3.8% on placebo, at 20.1% weight loss.
Has type 2 diabetes alongside obesity
Retatrutide
Blood sugar 8.0/10 against 2.5/10. Rosenstock 2023 reported HbA1c reductions up to 2.02% in type 2 diabetes. Eloralintide's pivotal trial excluded diabetics, so it has no glycemic result at all. That is a gap in the evidence rather than a demonstrated failure, and it is still a gap you would be running your glucose control on.
Has MASLD or measured high liver fat
Retatrutide
Liver 8.0/10 against 2.5/10. The glucagon arm exists to raise hepatic fat oxidation, and Sanyal 2024 measured the liver-fat reduction directly. Eloralintide has no liver endpoint in any trial. Both are still investigational, so the practical move is to treat the liver now with something approved.
Uses mealtime insulin or a sulfonylurea
Retatrutide
Not eloralintide without specialist supervision. The single boxed warning across the entire approved amylin class is severe low blood sugar in exactly that combination, carried by pramlintide's FDA label for twenty years. Retatrutide's report flags the same pairing for dose review rather than as a class boxed warning. Neither belongs in that combination unsupervised.
Resting heart rate already low, or on a rate-slowing medication
Retatrutide
A slow-heart-rate term showed up in 11% of eloralintide's 6 mg group and nobody on placebo, in small numbers that nobody has explained. Retatrutide pushes heart rate the other way, which is its own dose-related problem and a better-characterized one. If your resting rate is already low, the unexplained signal is the worse risk to take on.
Eligible for a Lilly trial and willing to enrol
Tie
Take whichever trial you qualify for. It is the only route to either molecule with manufactured product, a formal titration, monitoring and adverse-event tracking, and it is free. Eloralintide has five phase 3 studies recruiting, retatrutide has TRIUMPH and TRANSCEND. Both reports name trial enrollment as their best-case population.
Considering buying either one as research powder
Tie
Neither. FDA says retatrutide cannot be used in compounding and has not been found safe and effective for any condition, and eloralintide has even less regulatory standing than that. The vial has no product standard behind its label, no dose verification and no recourse. Eloralintide runs an estimated $432 to $540 a month for the privilege.
Research Highlights
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Mechanism Difference
These two are not variations on a theme. Retatrutide activates three incretin-family receptors at once, GLP-1, GIP and glucagon, the third one added to raise hepatic fat oxidation.Eloralintide activates a single receptor from a different hormone system, the amylin-1 receptor, 12-fold over the bare calcitonin receptor, driving satiety signaling in the hindbrain and slowing gastric emptying.That difference is the whole practical argument for eloralintide. The pancreatitis caution and thyroid tumor warning on incretin drugs come from that receptor's biology, and there is no reason to assume they carry across to an amylin drug.The class precedent is pramlintide, approved for twenty years, whose FDA label carries one boxed warning for low blood sugar with insulin and reports two-year rodent studies that found no drug-caused tumors.
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Tolerability Comparison
Tolerability is the one dimension where eloralintide is not simply the less-studied option. In its phase 2 trial, 2.9% of people on the drug discontinued for an adverse event, against 3.8% on placebo, at a weight loss of 20.1%. That combination is unusual for this field.Retatrutide's gastrointestinal burden is dose-related and documented in Jastreboff 2023, along with dysesthesia and heart-rate increases. Eloralintide's counterweight is smaller and stranger: a slow-heart-rate term in 11% of the 6 mg arm and none on placebo, unexplained, plus an open question about renin-angiotensin activation (Muskiet 2026).
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Evidence Maturity
Both sides are phase 2 and neither should be read as settled. Eloralintide has one good trial: 263 adults, mean BMI 39.1, published in The Lancet, with confidence intervals that exclude placebo in every arm. Retatrutide has two phase 2 trials, an MASLD substudy, a running phase 3 program and a topline press release.Both programs were funded and run by Eli Lilly, which owns both molecules. The network meta-analyses point the same way and are indirect: Kamrul-Hasan 2026 ranked high-dose eloralintide first while calling its own evidence base sparse and low certainty, and Xie 2024 ranked retatrutide first across 27 RCTs. Neither compared these two.
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Cost Comparison
Neither drug has a pharmacy price, because neither has a pharmacy. Both figures below are estimates for powder sold not for human use.Eloralintide runs an estimated $432 to $540 a month at the 9 mg dose that produced its headline result, priced 2026-09-08. Retatrutide is an estimated $128 to $320 at 4 mg weekly and $384 to $960 at 12 mg, priced 2026-09-07. Same band at the effective doses, and the same free alternative: a trial supplies the drug and the monitoring.
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Editorial Verdict
Retatrutide scores 5.6/10 and eloralintide 5.3/10, a 0.3 gap that decides nothing. On weight loss, the reason most people are reading this, they tie exactly at 7.5/10. Retatrutide takes six of the nine use cases because more of its work has been published: diabetes, liver, cardiovascular and joint data that eloralintide's single trial never attempted.The split that matters is narrower than the scoreboard. If incretin nausea is what ended your last attempt, eloralintide is the mechanism built to avoid it and the tolerability numbers back that up. If you also have diabetes or fatty liver, retatrutide is the one with measurements. For everyone else the answer is neither, because both readouts land in 2028 and an approved drug does the job today.
Frequently Asked Questions
- Is eloralintide better than retatrutide for weight loss?
- Neither is better. They tie at 7.5/10 for body composition, with 20.1% weight loss at 48 weeks for eloralintide and up to 24.2% for retatrutide, both from single phase 2 trials run by the same company. Retatrutide is ahead on the overall score, 5.6/10 to 5.3/10, because more of its work outside weight loss has been published.
- Can I buy either one?
- No, not legitimately. Neither is approved anywhere, neither can be prescribed and neither can be compounded. FDA says retatrutide has not been found safe and effective for any condition, and eloralintide has even less regulatory standing.The only route to either that comes with a real product, a titration and monitoring is a Lilly trial, and that route is free. Everything else is powder sold not for human use.
- Which one has fewer side effects?
- Eloralintide, on the evidence so far. Only 2.9% of people on it stopped for an adverse event against 3.8% on placebo, which is unusual at that weight-loss magnitude, and because it is an amylin drug rather than an incretin the pancreatitis and thyroid tumor warnings that follow the GLP-1 class do not automatically apply.It carries one signal retatrutide does not: a slow heart rate in 11% of the 6 mg group and nobody on placebo, in small numbers, unexplained. Retatrutide's gastrointestinal effects and heart-rate rise are dose-related and better characterized.
- How much does each cost per month?
- Both figures are estimates for research powder, not prices you can pay at a pharmacy. Eloralintide is an estimated $432 to $540 a month at 9 mg weekly, priced 2026-09-08 against roughly $12 per mg. Retatrutide is an estimated $128 to $320 at 4 mg weekly and $384 to $960 at 12 mg, priced 2026-09-07.
- Can I take eloralintide and retatrutide together?
- No. They act on different receptor systems, which makes the idea pharmacologically interesting and completely unstudied in humans, and it stacks two independent sets of gastrointestinal and heart-rate effects with no data on either. The only amylin plus incretin combination anybody is testing is eloralintide with tirzepatide, in a Lilly phase 2 trial that finished enrollment and has not reported.
- How long before I would know whether it is working?
- Twelve weeks for eloralintide, sixteen for retatrutide, and about a year for a full answer on either. Eloralintide moves the scale within four weeks and reached 2.6% to 11.3% by week twelve. Retatrutide changes appetite within one to two weeks. Both trials ran to 48 weeks and neither had plateaued when it stopped, so nobody knows where either effect settles.
- Does eloralintide protect muscle better than retatrutide?
- Nobody knows, and that is the honest state of it. Eloralintide's posted outcome list contains no body-composition measure at all, so no human lean-mass number exists for it. Rat work described the loss as mostly fat. Retatrutide is known to take lean mass unless training and protein are managed. Anyone losing weight at this rate needs resistance training and a real protein target either way.
- Who should not take either one?
- Anyone pregnant, trying to conceive or breastfeeding, and anyone with confirmed gastroparesis, since both slow stomach emptying. Eloralintide adds mealtime insulin or a sulfonylurea, the one boxed warning in the approved amylin class, plus oral medication where absorption timing matters and an already-low resting heart rate.Retatrutide adds a personal or family history of medullary thyroid carcinoma, MEN2, prior pancreatitis, active eating disorder, advanced kidney disease and significant cardiovascular disease without specialist oversight. Tested athletes should treat both as anti-doping risks.
Evidence Sources
- Eloralintide, a selective amylin receptor agonist for the treatment of obesity: a 48-week phase 2, multicentre, double-blind, randomised, placebo-controlled trial 263 adults, mean BMI 39.1, 48 weeks. Weight change from -9% at 1 mg to -20.1% at 9 mg against -0.4% on placebo, with 82.3% of the 9 mg arm losing at least 10%. Discontinuation for an adverse event 2.9% on drug against 3.8% on placebo.
- Eloralintide, a selective, long-acting amylin receptor agonist for treatment of obesity: Phase 1 proof of concept Weight change of 2.5% after a single 4 mg dose and 4.4% after 12 mg, reaching 2.6% to 11.3% by week twelve in the multiple-dose study. Reduced appetite was the most common complaint at 19%.
- Novel Amylin-Based Therapies for Weight Management in Adults With Overweight or Obesity Without Diabetes: A Network Meta-Analysis Six trials, 4,642 people. High-dose eloralintide ranked first for absolute weight loss, waist circumference and BMI reduction across the amylin and incretin field, in an indirect comparison the authors call sparse and low certainty.
- Amylin and the renin-angiotensin system: risk or opportunity in amylin-based therapy? Hypothesis paper published alongside the phase 2 trial arguing that amylin receptor agonism may activate the renin-angiotensin system in ways that undercut cardiovascular and kidney benefit. A question, not a finding.
- Eloralintide (LY3841136), a novel amylin receptor agonist for the treatment of obesity: From discovery to clinical proof of concept Rat work describing the weight loss as predominantly fat mass. Encouraging and not a human body-composition measurement, of which none has been published.
- NCT06230523 eloralintide phase 2 registry results Zero deaths, no pancreatitis case and lipase elevation at roughly the placebo rate. A slow-heart-rate term appeared in 11% of the 6 mg group and none of the placebo group.
- NCT07321886 ENLIGHTEN-1 phase 3 obesity trial Recruiting 1,980 people and supplying the drug free. One of five phase 3 eloralintide studies, none of which report before 2028.
- Lilly eloralintide phase 2 topline press release Sponsor reported improvements in waist circumference, blood pressure, lipids, glycemic markers and inflammatory markers with no numbers, confidence intervals or placebo comparison published for any of them.
- DailyMed SYMLIN (pramlintide acetate) prescribing information Twenty years of approved amylin use. One boxed warning for severe hypoglycemia with insulin, gastroparesis as an absolute contraindication, no pancreatitis warning, and two-year rodent studies finding no drug-caused tumors.
- Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial Phase 2 obesity RCT; up to 24.2% body-weight loss at 48 weeks, with dose-related gastrointestinal adverse events and heart-rate increases.
- Retatrutide for people with type 2 diabetes: randomized phase 2 trial Phase 2 type 2 diabetes RCT; HbA1c reduction up to 2.02% at 24 weeks and body-weight loss up to 16.94% at 36 weeks.
- Triple hormone receptor agonist retatrutide for MASLD: randomized phase 2a trial Phase 2a MASLD substudy with a large liver-fat reduction signal. Below the source report's Track 1 sample threshold.
- Seven GLP-1 receptor agonists and polyagonists for weight loss: updated network meta-analysis 27 RCTs, 15,584 participants. Retatrutide 12 mg and 8 mg ranked strongest for weight loss in an indirect comparison, not a direct head-to-head trial.
- TRIUMPH registrational clinical trials rationale and design Phase 3 program design for obesity, obstructive sleep apnea and knee osteoarthritis. A design source, not outcomes proof.
- Lilly TRIUMPH-4 topline obesity and knee osteoarthritis Phase 3 press release Company-reported topline: up to 28.7% body-weight loss and WOMAC pain improvement at 68 weeks. Not peer-reviewed at audit close.
- FDA: concerns with unapproved GLP-1 drugs used for weight loss FDA states retatrutide cannot be used in compounding, is not a component of an FDA-approved drug, and has not been found safe and effective for any condition.
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) 2,539 participants, 20.9% weight loss at 72 weeks. Cited on both source reports as the approved benchmark either drug would have to beat.
Glossary
Quick reference for the medical and technical terms used in this comparison.
- Amylin Amylin
- A hormone co-secreted with insulin that signals fullness, slows stomach emptying and damps glucagon. Eloralintide's target system, and a different one from the incretins.
- AMY1R Amylin-1 Receptor
- The receptor eloralintide selectively activates, 12-fold over the bare calcitonin receptor in human cells.
- CTR Calcitonin Receptor
- The core receptor that pairs with an accessory protein to form an amylin receptor. Selectivity over it matters because calcitonin activity affects bone.
- GLP-1 Glucagon-Like Peptide-1
- An incretin hormone that raises glucose-dependent insulin secretion, slows gastric emptying and suppresses appetite. Retatrutide acts on its receptor; eloralintide does not.
- GIP Glucose-Dependent Insulinotropic Polypeptide
- The second incretin hormone. Retatrutide activates its receptor, which amplifies insulin signaling and affects how adipose tissue handles energy.
- GCGR Glucagon Receptor
- Retatrutide's third receptor, added to raise hepatic fat oxidation and energy expenditure. It is the reason retatrutide has a liver claim and eloralintide does not.
- Pramlintide Pramlintide
- The only approved amylin drug, on the market for twenty years. Its FDA label is the class precedent for what an amylin drug's risks look like.
- HbA1c Glycated Hemoglobin
- A two to three month average of blood glucose and the primary endpoint in most diabetes trials, including Rosenstock 2023. Eloralintide has no HbA1c result because its trial excluded diabetics.
- MASLD Metabolic Dysfunction-Associated Steatotic Liver Disease
- Fatty liver disease linked to metabolic dysfunction, formerly NAFLD. The population in Sanyal 2024's retatrutide liver-fat substudy. Eloralintide has no liver endpoint.
- Bradycardia Bradycardia
- An abnormally slow heart rate. Reported in 11% of eloralintide's 6 mg group and none of the placebo group, in small numbers and so far unexplained.
- Gastroparesis Gastroparesis
- Delayed stomach emptying. An absolute contraindication on the pramlintide label and a mechanistic problem for any drug that slows the stomach further, which both of these do.
- Phase 2 Phase 2 trial
- A mid-stage trial testing dose and effect in hundreds of people, not thousands. Both drugs' best evidence is phase 2, which is why both scores are directional rather than settled.
- NMA Network Meta-Analysis
- A statistical comparison of drugs that were never tested against each other, made through their shared placebo arms. Both rankings cited here are of this indirect kind.
- ENLIGHTEN Lilly's phase 3 eloralintide program
- Five registrational trials including ENLIGHTEN-1 in obesity at 1,980 people and ENLIGHTEN-2 in 1,035 people with type 2 diabetes. First readouts in 2028.
