Amylin Therapies: The Next Generation of Weight-Loss Drugs Beyond GLP-1s

The Weight-Loss Drug Landscape Is Shifting

For the past three years, GLP-1 receptor agonists have dominated the obesity treatment conversation. Semaglutide and tirzepatide became household names. But at the 2026 American Diabetes Association Scientific Sessions in New Orleans and the European Congress on Obesity in Istanbul, a different story emerged from the data: amylin-based therapies are positioning themselves as the next major drug class for weight management—and they may solve problems that GLP-1s can’t.

The evidence is mounting fast. A network meta-analysis published in May 2026 synthesized data from six randomized controlled trials covering 4,642 participants. The ADA hosted a dedicated symposium titled “Amylin as a Novel Diabetes and Obesity Therapy.” And Novo Nordisk’s REDEFINE-1 trial produced body composition data that directly addresses the biggest criticism leveled at GLP-1 drugs: muscle loss.

What Is Amylin, and Why Does It Matter?

Amylin is a 37-amino-acid peptide hormone co-secreted with insulin from pancreatic beta cells. It works in the subcortical areas of the brain—specifically the hypothalamus and area postrema—to regulate satiety, slow gastric emptying, and suppress glucagon secretion. The FDA approved pramlintide, a synthetic amylin analog, back in 2005 for diabetes management. But pramlintide was short-acting and required multiple daily injections, limiting its adoption.

The new generation of amylin analogs are engineered for once-weekly dosing and substantially greater potency. They activate amylin receptors (AMY1R and AMY3R) as well as calcitonin receptors, creating a pharmacological profile that differs meaningfully from GLP-1 agonists. Where GLP-1s primarily act through incretin pathways to suppress appetite and slow gastric emptying, amylin analogs engage different neural circuits—and that difference may explain their distinct clinical advantages.

The Clinical Data: Three Headlines That Matter

1. CagriSema achieves 22.7% weight loss with favorable body composition

The REDEFINE-1 trial enrolled 3,417 adults with obesity (BMI ≥30 or ≥27 with complications) and randomized them to CagriSema (cagrilintide 2.4 mg + semaglutide 2.4 mg), semaglutide alone, cagrilintide alone, or placebo. At 68 weeks, CagriSema produced a mean weight reduction of 22.7% on the trial-product estimand—compared to 16.6% with semaglutide alone and 15.0% with cagrilintide alone.

The body composition data, presented at ECO 2026 in Istanbul, is what grabbed clinicians’ attention. In a 252-person DXA substudy, 66.9% of weight lost on CagriSema came from fat mass and 33.1% from lean soft tissue. Among participants who achieved ≥30% weight loss, the proportion of body fat dropped from 46.3% to 33.2%, while lean soft tissue actually increased from 51.3% to 63.2% of total body composition. Muscle strength, measured by sit-to-stand testing, was preserved relative to placebo.

2. Eloralintide delivers 20% weight loss as monotherapy

Eli Lilly’s selective amylin receptor agonist eloralintide showed dose-dependent weight loss in Phase 2 trials, reaching 20% at the 9 mg dose. Importantly, when titration was optimized (3 mg to 9 mg gradually), vomiting rates dropped from 11% to just 2%—demonstrating that tolerability is a function of dosing strategy, not an inherent limitation of the drug class. Eloralintide is now in Phase 3 trials and being tested in combination with tirzepatide.

3. Petrelintide achieves ~10% weight loss with minimal GI effects

Roche/Zealand Pharma’s petrelintide reported Phase 2 data in March 2026 showing approximately 10% weight reduction with a standout tolerability profile: roughly 70% of participants on the highest dose reported zero gastrointestinal adverse events. While the weight loss numbers are lower than competitors, the tolerability data is striking for patients who couldn’t tolerate GLP-1 side effects.

The “Quality of Weight Loss” Argument

This is where amylin developers are making their most compelling case. The obesity pharmacotherapy field has been locked in a percentage-weight-loss arms race—who can show the biggest number on the scale. Amylin advocates are reframing the conversation around what they call “health-gain drugs.”

Dr. Carel le Roux of University College Dublin, presenting at the ADA symposium, put it directly: “Not only are these weight loss drugs, these are also health-gain drugs, gains that we can materialize when we are treating our patients.” His point: the relevant metric isn’t just how much weight you lose, but what kind of weight you lose—and whether you can keep it off.

Preclinical data from Dr. Thomas Alexander Lutz at the University of Zurich adds mechanistic weight to this argument. His lab has shown that amylin analogs reduce bone resorption and increase bone formation—a property not shared by GLP-1 agonists. They also attenuate the typical decrease in energy expenditure that follows caloric restriction and weight loss, which may help explain why amylin-treated subjects maintain their results better over time.

The Real-World Signal: What Patients Are Saying

The community conversation around amylin compounds is accelerating. A post on r/GLP1ResearchTalk titled “Cagrilintide is an absolute force multiplier for your existing GLP-1” received 41 upvotes and 89 comments, with users describing it as “a straight up stallbuster” and noting “the synergistic effect with Tirzepatide is amazing.” On r/Retatrutide, a post about the eloralintide Phase 2 Lancet paper drew 170 upvotes, with one user calling it “the next big thing after Retatrutide.”

These aren’t isolated data points. The pattern is consistent: patients who hit plateaus on GLP-1 monotherapy are finding that adding an amylin analog restarts weight loss, often with fewer GI side effects than they experienced during GLP-1 titration. For the peptide community, this validates what clinicians are seeing in trial data—amylin and GLP-1 pathways are complementary, not competitive.

The Pipeline: Who’s Building What

The amylin landscape is crowded and well-funded. Novo Nordisk is seeking FDA approval for CagriSema as a once-weekly injection. Eli Lilly has eloralintide in Phase 3 and is testing it alongside tirzepatide. Roche/Zealand Pharma’s petrelintide is advancing through trials with a tolerability-first positioning. AbbVie licensed a long-acting amylin analog from Gubra with Phase 1 data. Alveus Therapeutics has two amylin candidates (peptide and small molecule) in preclinical development. And Pfizer acquired Metsera in 2025 for $6 billion, gaining access to an amylin analog candidate in the process.

The competitive dynamics are clear: every major obesity drug developer now has an amylin program. The global weight-loss drug market is projected to reach $150 billion by 2035, and no company wants to be left without a presence in what could become the second-largest drug class after GLP-1s.

What This Means for You

If you’re currently on a GLP-1 receptor agonist and experiencing muscle loss, GI intolerance, or a weight-loss plateau, the amylin pipeline offers something concrete to watch. CagriSema could receive FDA approval in late 2026 or early 2027, making it the first amylin-inclusive combination therapy available by prescription.

For the peptide community specifically, the research peptide versions of cagrilintide and eloralintide are already circulating. The clinical data strongly suggests that combining an amylin analog with your existing GLP-1 protocol may produce better results than either agent alone—with the critical caveat that these are not yet FDA-approved for weight management, and the usual disclaimers about research peptides apply.

The broader takeaway is that obesity pharmacotherapy is maturing beyond single-target drugs. Dr. Timothy Garvey of the University of Alabama at Birmingham, moderating the ADA symposium, captured the direction: “I hope they will continue to think outside the GLP-1 box to develop new mechanisms of action, new drugs that help us better individualize care.” Amylin is the first serious proof that this approach works.

Evidence Grade

Evidence Grade: A- (Strong)

Multiple Phase 3 randomized controlled trials (REDEFINE-1, REDEFINE-2), Phase 2 dose-finding studies (eloralintide, petrelintide), a network meta-analysis of 6 RCTs with 4,642 participants, mechanistic preclinical data, and consistent real-world user reports. The evidence base is robust and growing. Grade held back from A because long-term (>2 year) persistence and safety data are still emerging.

Sources

1. “Novel Amylin-Based Therapies for Weight Management in Adults With Overweight or Obesity Without Diabetes: A Network Meta-Analysis.” Endocrinology, Diabetes & Metabolism, May 2026. PMID: 42175595

2. “Positive data from multiple amylin trials draw focus to novel therapeutic mechanism.” ADA Meeting News, June 5, 2026.

3. “ECO 2026: REDEFINE-1 demonstrates CagriSema’s improvement in body composition.” Pharmaceutical Technology, May 13, 2026.

4. “Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity.” New England Journal of Medicine, 2025. NCT05567796.

5. “Can amylin weight-loss drugs compete in a world of GLP-1s?” Chemical & Engineering News, April 2026.

6. “Long-acting amylin-related peptides as therapies for diabetes and obesity.” Peptides journal, 2026. ScienceDirect.

7. “Cagrilintide lowers bodyweight through brain amylin receptors 1 and 3.” eBioMedicine, 2025. PMC12270663.

8. Reddit: r/GLP1ResearchTalk, r/Retatrutide — community discussion on cagrilintide and eloralintide stacking.