Eloralintide vs cagrilintide is the comparison everyone wants, and no human trial has run it yet. Both are investigational once-weekly amylin injections, one from Eli Lilly and one from Novo Nordisk, and neither is FDA approved.
The real difference is the receptors they hit. Eloralintide is built to prefer one amylin receptor. Cagrilintide hits amylin and calcitonin receptors about equally. Cagrilintide has far more human data. Eloralintide has the longer single-drug phase 2. So which one is stronger? Nobody knows yet. Anyone who hands you a winner is guessing.
If you’ve seen both names in a headline and wondered which one wins, this is what the trials actually show.
The short answer
Verdict as of October 5, 2026
- Different receptor profiles. In human cell tests, eloralintide is about 12 times more potent at the AMY1 amylin receptor than at the calcitonin receptor. Cagrilintide is close to equal at both.
- No head-to-head human trial. ClinicalTrials.gov lists zero trials testing one against the other.
- Cagrilintide has more human data. 706 people took it alone in phase 2 and 302 more in phase 3. Another 3,012 took it as part of CagriSema in REDEFINE 1 and 2.
- Eloralintide has the longer single-drug phase 2. It ran 48 weeks. Cagrilintide’s phase 2 ran 26 weeks.
- Neither is approved. Eloralintide is in phase 3. CagriSema, the cagrilintide plus semaglutide combo, is under FDA review.
Eloralintide vs cagrilintide
| Attribute | Eloralintide | Cagrilintide |
|---|---|---|
| Maker | Eli Lilly | Novo Nordisk |
| Code name | LY3841136 | AM833 (NN0174-0833) |
| Class | Selective amylin receptor agonist | Long-acting amylin analogue, also hits calcitonin receptor |
| Receptor preference (human cells) | About 12x for AMY1 over calcitonin receptor | About equal at both |
| Half-life | About 13 to 15 days | About 7 to 8 days |
| Dosing in trials | Once-weekly injection | Once-weekly injection |
| Lead single-drug trial | Phase 2, The Lancet, 2025 | REDEFINE 1 cagrilintide arm, phase 3 |
| Duration and size | 48 weeks, 263 adults | 68 weeks, 302 on cagrilintide alone |
| Weight loss vs placebo | 9.5% to 20.1% vs 0.4% (efficacy estimand) | 11.8% vs 2.3% (trial-product estimand) |
| Comparator | Placebo | Placebo, plus a semaglutide arm |
| Stage | Phase 3 ENLIGHTEN, recruiting | Phase 3 RENEW; CagriSema under FDA review |
| FDA approved | No | No |
What amylin does and why drugmakers want it
Amylin is a hormone your pancreas releases with insulin after you eat. It tells your brain you’ve had enough. It slows how fast your stomach empties. It also holds back glucagon, the hormone that pushes blood sugar up after a meal.
How amylin works, simplified
- You eat.
- Beta cells in your pancreas release insulin and amylin together.
- Amylin acts on the brainstem and hypothalamus.
- You feel full sooner, your stomach empties more slowly and glucagon drops.
So why not inject amylin itself? Human amylin clumps into sticky fibrils and clears from the blood fast. As a drug, it doesn’t work.
The first workaround was pramlintide (Symlin), approved in 2005 for diabetes. It lasts 30 to 50 minutes, so people inject it before meals. It carries a boxed warning for severe low blood sugar when used with insulin. In one-year obesity studies it gave about 5% to 7% more weight loss than placebo.
Eloralintide and cagrilintide fix the timing problem. Both carry a fatty acid tail that sticks to albumin in your blood. That slows clearance enough for one shot a week instead of one before every meal.
The real difference: receptor selectivity
Amylin receptors are built from two parts. The base is the calcitonin receptor. Add a partner protein called RAMP1, RAMP2 or RAMP3 and you get AMY1, AMY2 or AMY3. The calcitonin receptor on its own mostly answers to calcitonin, a hormone tied to calcium and bone.
So “selective” means one thing here. How much does a drug prefer the amylin receptors over the bare calcitonin receptor?
Eloralintide: prefers the AMY1 receptor
In Lilly’s human cell tests, eloralintide was about 12 times more potent at AMY1 than at the calcitonin receptor. It was about 11 times more potent at AMY1 than at AMY3. In binding tests the gap was about 8-fold.
In rat cells the gap was far wider, about 45-fold on potency and 109-fold on binding. Keep that in mind when you read rat results. The drug looks much more selective in rats than in people. Lilly’s own authors write that “there is no established minimum selectivity threshold to define biologically relevant selectivity.”
Eloralintide also stays in your body a long time. Its half-life in phase 1 was 12.9 to 15.3 days, about twice cagrilintide’s.
Blood levels stay flat across the week. That cuts both ways. Effects build slowly, and side effects fade slowly. Lilly’s phase 2 added a 10-week safety follow-up for exactly this reason.
What’s established is the cell data and the long half-life. What’s still Lilly’s hypothesis is that selectivity means fewer side effects. Lilly’s own phase 1 paper offers a second explanation. It says the drug’s tolerability “may be attributable to its pharmacokinetic properties,” meaning those slow, steady blood levels.
Selective amylin drugs aren’t new, either. Lilly writes that pramlintide also “has little action at calcitonin receptors.” The new part is selectivity plus once-weekly dosing.
Cagrilintide: hits amylin and calcitonin receptors about equally
Cagrilintide is non-selective. In Novo’s assays it needed almost the same concentration to switch on the human amylin receptor (49 pM) as the calcitonin receptor (62 pM). That’s close to a tie. Its half-life is 159 to 195 hours, about 6.6 to 8.1 days.
Is hitting the calcitonin receptor bad? Not proven.
Novo built its own selective amylin compound, NN1213. In rats it cut food intake by 25% at a dose where cagrilintide cut it by 45%.
Novo’s scientists wrote that “some efficacy was lost.” So calcitonin receptor activity may add weight loss along with side effects. Nobody has tested that directly in people.
What the human trials show
Eloralintide phase 2 (The Lancet, 48 weeks, 263 adults)
Lilly’s phase 2 trial enrolled 263 adults with obesity, or overweight plus a weight-related condition, and no type 2 diabetes. It ran at 46 US sites. Women made up 78% of the group, and the average BMI was 39.1.
People got weekly placebo or eloralintide at 1, 3, 6 or 9 mg. Two more groups stepped up to 9 mg, one from 6 mg and one from 3 mg.
In this 48-week phase 2 of 263 adults, eloralintide cut body weight by 9.5% to 20.1% across doses, against 0.4% on placebo, using Lilly’s efficacy estimand. The 20.1% came from 9 mg started at full dose.
The same 48-week trial of 263 adults also reports an “everyone counts” analysis, which includes people who stopped treatment. On that basis, weight loss was 7.3% to 17.5% against 2.3% on placebo.
Weight loss hadn’t plateaued at 48 weeks for any dose. In the same 263-person trial, waist size fell by up to 17.1 cm at 48 weeks, against 1.1 cm on placebo.
Cagrilintide (phase 2 and REDEFINE 1)
Novo’s phase 2 trial randomized 906 adults without diabetes in 10 countries. Of those, 706 got cagrilintide at 0.3 to 4.5 mg weekly, 99 got liraglutide and 101 got placebo. In this 26-week phase 2, cagrilintide cut body weight by 6.0% to 10.8% across doses, against 3.0% on placebo.
The phase 3 data comes from REDEFINE 1, a 68-week trial of 3,417 adults. Most got CagriSema. Only 302 got cagrilintide 2.4 mg alone.
In REDEFINE 1, those 302 people lost 11.8% of body weight at 68 weeks against 2.3% on placebo, assuming everyone stayed on treatment.
Counting everyone regardless of adherence, the same 302-person arm lost 11.5% at 68 weeks against 3.0% on placebo.
Novo then launched RENEW, a dedicated phase 3 program for cagrilintide alone.
Why you can’t compare the two headline numbers
Don’t put the two headline numbers side by side and pick a winner. Here’s why.
- Different phases. One is phase 2. The other is phase 3.
- Different lengths. 48 weeks against 68 weeks.
- Different statistics. Lilly’s headline uses an efficacy estimand. Novo’s uses a trial-product estimand. Each company defines its “everyone counts” version a little differently too.
- Different placebo groups. Under the headline methods, placebo lost 0.4% in one trial and 2.3% in the other.
- Different people. Lilly’s trial was US-only and 78% women.
- Different dose starts. Several eloralintide arms started at full dose with no step-up.
Only a head-to-head trial settles it. None exists.
The rat head-to-head, and its limits
The only direct comparison is a rat study. Lilly ran it and paid for it, and every author worked for Lilly.
Two findings get quoted everywhere.
- Less nausea-like behavior. Rats can’t vomit, so researchers use conditioned taste avoidance as a stand-in. Eloralintide caused less of it than cagrilintide at doses that cut food intake about equally.
- Less lean mass loss. In obese rats, both drugs cut fat about equally. Eloralintide lost less lean mass.
Here’s what usually gets left out. In that same head-to-head, at the same dose, cagrilintide caused more total weight loss, 13.3% against 11.1% for eloralintide at day 15.
The two drugs were also mixed in different buffers, pH 4 for cagrilintide and pH 8 for eloralintide. The taste tests were separate experiments. And Lilly’s authors call the cause of the lean mass difference “unclear,” because lean mass includes muscle, bone and water.
Then there’s the species problem. Eloralintide is about 45 times selective in rat cells and about 12 times in human cells. A rat advantage may shrink in people.
Novo’s rat data points the other way on appetite. Its own selective compound lost some of the food-intake effect that cagrilintide had.
So you get useful animal signals and zero human proof.
Side effects and tolerability
Both drugs mostly cause stomach side effects. Eloralintide adds a few that GLP-1 users won’t expect.
Eloralintide (phase 2, 48 weeks, 263 adults)
How common was each side effect at each eloralintide dose?
| Side effect | Placebo | 6 mg, no step-up | 9 mg, no step-up | 3 to 6 to 9 mg step-up |
|---|---|---|---|---|
| Nausea | 13% | 64% | 33% | 25% |
| Vomiting | 0% | 25% | 11% | 2% |
| Fatigue | 12% | 29% | 43% | 21% |
| Diarrhea | 10% | 36% | 11% | 17% |
| Constipation | 6% | 7% | 24% | 8% |
| Hair loss | 0% | 4% | 9% | 10% |
| Stopped due to side effects | 8% | 21% | 7% | 12% |
Starting low cut side effects sharply. People who started on 6 mg had 64% nausea and 25% vomiting. People who climbed from 3 mg had 25% nausea and 2% vomiting.
Fatigue reached 43% to 46% in the 9 mg and 6-to-9 mg groups. The Lancet authors say that’s more than usually seen with incretin drugs. Hair loss showed up in 7% of everyone on eloralintide and in nobody on placebo.
Heart rate went down, the opposite of GLP-1 drugs. One person stopped for a slow heart rate with no symptoms. What that means for heart risk is unknown.
Cagrilintide (phase 2, 26 weeks, 706 on drug)
How common was each side effect in cagrilintide’s phase 2?
| Side effect | Placebo | 2.4 mg | 4.5 mg |
|---|---|---|---|
| Nausea | 17.8% | 31.4% | 46.5% |
| Vomiting | 3.0% | 8.8% | 7.9% |
| Constipation | 6.9% | 16.7% | 20.8% |
| Diarrhea | 8.9% | 17.6% | 6.9% |
| Injection site reaction | 0% | 11.8% | 9.9% |
| Injection site redness | 0% | 6.9% | 16.8% |
Injection-site reactions are cagrilintide’s extra. Placebo had none. In the 68-week REDEFINE 1 arm of 302 people, nausea ran about 24%, and 1.0% quit because of nausea against 0.1% on placebo.
Combinations: CagriSema and EloraTZP
Combination results are not single-drug results. Keep them separate when you read headlines.
CagriSema is cagrilintide 2.4 mg plus semaglutide 2.4 mg in one weekly shot. It’s investigational. In the 68-week REDEFINE 1 trial, the 2,108 adults on CagriSema lost 20.4% of body weight against 3.0% on placebo. Then it lost a head-to-head.
In REDEFINE 4, an 84-week trial of 809 adults, CagriSema failed to prove it was as good as tirzepatide 15 mg. Counting everyone in that 84-week, 809-person trial, CagriSema produced 20.2% weight loss against 23.6% for tirzepatide.
Novo filed CagriSema with the FDA in December 2025 and expects a decision in Q4 2026.
EloraTZP is eloralintide plus tirzepatide, also investigational. Lilly presented phase 2b results at EASD on September 30, 2026. In this 48-week trial of 367 adults with obesity and type 2 diabetes, the top combo dose cut body weight by 23.3%, against 14.8% for tirzepatide 15 mg alone and 3.0% on placebo.
That trial also had small eloralintide-only arms of roughly 37 people each. In those 48-week arms, people with type 2 diabetes lost 8.2% to 12.3% on eloralintide alone, against 3.0% on placebo. The 9 mg dose did no better than 6 mg.
Side-effect dropouts in the combo arms ran 10.8% to 27.0%, against 2.9% for tirzepatide alone. Lilly plans phase 3 of a single-shot EloraTZP by the end of 2026.
How both compare with GLP-1 drugs
Amylin comes from your pancreas. GLP-1 comes from your gut. Both cut appetite, through partly different brain pathways. That’s why companies pair them.
No trial has tested eloralintide alone against tirzepatide or semaglutide. Cagrilintide alone has one GLP-1 comparison. In its 26-week phase 2 with 906 adults randomized, cagrilintide 4.5 mg cut weight by 10.8% against 9.0% for liraglutide 3.0 mg.
There’s one practical difference. GLP-1 drugs tend to raise heart rate, and eloralintide lowered it in trials.
Lilly is also testing eloralintide as an add-on for people whose weight stalled on a weekly incretin. That trial is ENLIGHTEN-6, with 900 adults.
Novo’s single-molecule amylin and GLP-1 drug is now called zenagamtide, formerly amycretin.
Cagrilintide also has an entry in our list of peptides.
Approval status and availability
Status as of October 5, 2026
- Eloralintide. Investigational, not approved. Phase 3 ENLIGHTEN is recruiting. ENLIGHTEN-1 (1,980 adults without diabetes) and ENLIGHTEN-2 (1,035 adults with type 2 diabetes) list primary completion in 2028. No filing yet.
- Cagrilintide alone. Investigational, not approved. RENEW 1 (300 adults) lists primary completion in May 2027.
- CagriSema. Under FDA review. Filed December 2025. Decision expected in Q4 2026.
- Head-to-head trial. None registered.
When could eloralintide launch? Nobody knows. No filing exists and the main phase 3 trials finish in 2028. Ignore any launch date you see online.
Can you get either drug now? Only in a clinical trial. Search ClinicalTrials.gov for ENLIGHTEN or RENEW.
If you need treatment today, approved prescription options include Wegovy (semaglutide) and Zepbound (tirzepatide). A prescriber can tell you if either fits.
The FDA says cagrilintide cannot be used in compounding under federal law. In March 2026 it warned a seller offering cagrilintide labeled “for laboratory research purposes only.” The FDA said the label didn’t matter, because the products were drugs meant for people.
Our breakdown of fake peptide vendors and FDA warnings covers the same letter in more detail.
Online “research peptides” have no verified sterility, identity or dose. You don’t know what’s in the vial. Don’t inject it.
Frequently asked questions
Which is stronger, eloralintide or cagrilintide?
Nobody knows. They’ve never been tested against each other in people. Eloralintide’s 48-week phase 2 in 263 adults reported 9.5% to 20.1% weight loss against 0.4% on placebo. Cagrilintide alone produced 11.8% against 2.3% on placebo in the 68-week REDEFINE 1 arm of 302 people. The trials differ too much to call a winner.
Has anyone tested them against each other?
Only in animals. The only cagrilintide vs eloralintide data in living animals comes from rat studies that Lilly funded and ran. Eloralintide caused less taste avoidance and less lean mass loss. Cagrilintide caused more total weight loss. As of October 5, 2026, no human head-to-head trial is registered.
Does selectivity mean fewer side effects?
Not proven. Lilly’s rat data point that way. But Lilly’s own phase 1 paper says eloralintide’s tolerability may come from its slow, steady blood levels instead. In the phase 2 trial, the dose start mattered most. Starting at 6 mg gave 64% nausea. Stepping up from 3 mg to 9 mg gave 25%.
Do they cause muscle loss?
Some of the weight lost on any weight-loss drug is lean mass. In eloralintide’s phase 2 body-scan substudy, people lost about three parts fat for every one part lean mass, similar to other weight-loss studies. Rats on eloralintide lost less lean mass than rats on cagrilintide. Nobody has tested that difference in people.
Is fatigue a problem?
For eloralintide, yes, at higher starting doses. In the 48-week phase 2, fatigue hit 43% on 9 mg started at full dose, against 12% on placebo. Stepping up from 3 mg cut it to 21%. The Lancet authors say fatigue was more common than usually seen with incretin drugs. Cagrilintide’s trials report mostly stomach effects.
Is either one FDA approved?
No. As of October 5, 2026, neither eloralintide nor cagrilintide is FDA approved. Eloralintide is in phase 3. Cagrilintide alone is in phase 3 too. CagriSema, which pairs cagrilintide with semaglutide, is under FDA review, and Novo Nordisk expects a decision in Q4 2026.
Can I get either drug now?
Only by joining a clinical trial. Search ClinicalTrials.gov for ENLIGHTEN for eloralintide or RENEW for cagrilintide. Online “research peptides” are unregulated. The FDA has warned sellers that a “research use only” label doesn’t make them legal. Nobody verifies what’s in the vial.
What dose do people use?
No approved dose exists for either drug. Trials tested eloralintide at 1 to 9 mg weekly and cagrilintide at 0.3 to 4.5 mg weekly, with planned step-ups and medical monitoring. Those are research settings, not instructions. If you want medical weight-loss treatment, a prescriber can walk you through approved options.
Conclusion
Eloralintide and cagrilintide are both investigational, and neither is approved. They differ in receptor preference and half-life. Nobody has compared them in people, so any winner you read about is a guess. Cagrilintide has more human data. Eloralintide’s side effects depend heavily on how the dose starts.
Watch the dates. The CagriSema FDA decision is expected in Q4 2026. RENEW 1 should read out after May 2027. ENLIGHTEN-1 and ENLIGHTEN-2 finish in 2028.
Sources
- Billings LK, et al. Eloralintide, a selective amylin receptor agonist for the treatment of obesity: a 48-week phase 2 trial. The Lancet, 2025.
- Briere DA, et al. Eloralintide (LY3841136), a novel amylin receptor agonist: from discovery to clinical proof of concept. Molecular Metabolism, 2025.
- Bhattachar S, et al. Eloralintide phase 1 proof of concept. Diabetes, Obesity and Metabolism, 2026.
- Lau DCW, et al. Once-weekly cagrilintide for weight management: a dose-finding phase 2 trial. The Lancet, 2021.
- ClinicalTrials.gov. NCT03856047, cagrilintide phase 2 posted results.
- Garvey WT, et al. Coadministered cagrilintide and semaglutide in adults with overweight or obesity (REDEFINE 1). New England Journal of Medicine, 2025.
- Novo Nordisk. Phase 3 data for cagrilintide, EASD 2025.
- Enebo LB, et al. Cagrilintide with semaglutide 2.4 mg, phase 1b. The Lancet, 2021.
- NN1213, a potent, long-acting and selective analog of human amylin. Journal of Medicinal Chemistry, 2024.
- Horn CC, et al. Why can’t rodents vomit? PLoS One, 2013.
- Alhazmi A, le Roux CW. Amylin analogs: the next major class of weight loss therapy. Diabetes, Obesity and Metabolism, 2026.
- Eli Lilly. EloraTZP phase 2b results, September 30, 2026.
- Novo Nordisk. Form 6-K, February 23, 2026 (REDEFINE 4 and CagriSema FDA filing).
- Novo Nordisk. Financial report for H1 2026, Form 6-K, August 4, 2026.
- ClinicalTrials.gov: ENLIGHTEN-1, NCT07321886; ENLIGHTEN-2, NCT07282600; ENLIGHTEN-6, NCT07392190.
- ClinicalTrials.gov. RENEW 1 (NCT07220642).
- U.S. FDA. FDA’s concerns with unapproved GLP-1 drugs used for weight loss.
- U.S. FDA. Warning letter to Prime Sciences, March 31, 2026.
- SYMLIN (pramlintide) prescribing information.