Evidence review
Amylin Analogs: The Next Class After Incretins
An amylin analog has been FDA-approved since 2005. What changed is not the hormone — it is how long the molecule lasts. The trials, in order.
Amylin is not new
Amylin is a hormone the pancreas releases alongside insulin. It slows gastric emptying, suppresses glucagon after meals, and produces satiety.
Pramlintide, a synthetic amylin analog, has carried an FDA-approved label since 2005. So the honest version of "amylin is the next class" is narrower: the hormone is old, the trials are old, and the thing that changed is how long the molecule survives in the body.
The 48-minute problem
The approved amylin analog's label states that pramlintide's half-life in healthy individuals is approximately 48 minutes, and that it does not extensively bind albumin — roughly 40% of the drug is unbound in plasma1.
Forty-eight minutes means dosing before meals, several times a day. That is a real adherence tax, and it shaped the obesity trials the molecule appeared in.
Compare that with a long-acting amylin analog in current development. Petrelintide's phase 1 programme reported a half-life of approximately 10 days2. Ten days is once-weekly territory.
That is the entire generational shift in this class, and we take the general principle apart in half-life and dosing frequency.
What the approved amylin analog actually did for weight
A 204-participant phase 2 trial randomised non-insulin-treated adults with obesity, with and without type 2 diabetes, to pramlintide or placebo three times a day before meals for 16 weeks, without any concurrent lifestyle intervention. Participants completing the 16 weeks had a placebo-corrected weight reduction of 3.7 ± 0.5%, and about 31% reached at least 5% weight loss against 2% on placebo3.
A 12-month study followed: 411 adults randomised for four months alongside a structured lifestyle programme, with 77% of the four-month evaluable participants continuing into an eight-month single-blind extension. Placebo-corrected weight loss at month 12 averaged 5.6 ± 2.1% and 6.8 ± 2.3% in the two regimens that maintained it4.
Those are real, placebo-controlled, single-digit results. Set against the double-digit incretin figures elsewhere on this site, they explain why amylin sat quiet for fifteen years.
The long-acting version, alone
Cagrilintide is a long-acting amylin analog. Its phase 2 dose-finding trial randomised 706 participants across five cagrilintide doses, plus 99 to once-daily liraglutide 3.0 mg and 101 to placebo, for 26 weeks5.
Under the trial product estimand, mean weight reductions ranged from 6.0% to 10.8% across the cagrilintide doses against 3.0% on placebo. The highest cagrilintide dose was also compared with liraglutide directly: 10.8% against 9.0%, an estimated treatment difference of 1.8% with p = 0.035.
That last comparison is the useful one, because it was a within-trial randomised contrast rather than an arithmetic across studies. It is also modest — 1.8 percentage points.
Our cagrilintide page holds the full programme.
The combination, and what it does and does not isolate
REDEFINE 1 is the large one. A 68-week phase 3a trial randomised 3,417 adults without diabetes in a 21:3:3:7 ratio to cagrilintide-semaglutide, semaglutide alone, cagrilintide alone, or placebo — 2,108, 302, 302 and 705 participants respectively6.
The published coprimary result: mean percent change in body weight from baseline to week 68 was −20.4% with the combination against −3.0% with placebo, an estimated difference of −17.3 percentage points. Gastrointestinal adverse events affected 79.6% of the combination group and 39.9% of placebo6.
Here is the discipline this page exists to enforce. The trial *did* include monotherapy arms, which is exactly right, but the coprimary comparison reported in that abstract is combination against placebo. Reading −20.4% as "amylin adds six points to semaglutide" is arithmetic against a number from a different trial, not a within-trial contrast. The semaglutide page carries what the semaglutide monotherapy trials reported on their own terms.
What amylin might be for
The pitch is not that amylin beats a GLP-1 drug. It is tolerability.
The petrelintide phase 1 report describes nausea in 16.7% to 33.3% of participants receiving petrelintide against 16.7% for placebo in the multiple-ascending-dose part, with diarrhoea rare and one participant discontinuing for gastrointestinal events. It reported body weight reduction of up to 8.6% after 16 weeks2.
That is a phase 1 trial. Phase 1 is where a molecule is checked for safety in small numbers, and its tolerability figures come from too few people to be a reliable estimate of what phase 3 will show. The 8.6% is real and it is also fragile.
Where the class stands, as of August 2026
Approved: one amylin analog, pramlintide, dosed before meals, with obesity results in the single digits3.
Phase 3 reported: cagrilintide, but as one half of a coadministered pair rather than as monotherapy in that trial6.
Phase 1 reported: petrelintide, with a weekly-compatible half-life and a 16-week weight figure from an ascending-dose study2.
A ClinicalTrials.gov search for petrelintide-class amylin monotherapy against a GLP-1 comparator in a phase 3 obesity setting is the trial that would answer the tolerability question. The cagrilintide phase 2 did run an active liraglutide comparator5; we did not find a published phase 3 that randomised a long-acting amylin monotherapy against a current GLP-1 comparator as of August 2026.
For how the whole field lines up against a goal rather than against each other, see weight loss, and for what the receptors in the incretin class actually do, incretins explained.
Frequently asked questions
Is there an approved amylin drug?
Yes. Pramlintide, a synthetic amylin analog, has carried an FDA-approved label since 2005. Its label states a half-life of approximately 48 minutes, which is why it is dosed before meals rather than weekly.
How much weight did the approved amylin analog produce?
A 204-participant 16-week phase 2 trial without a lifestyle programme reported placebo-corrected weight reduction of 3.7 ± 0.5%, with about 31% of participants reaching at least 5% loss against 2% on placebo. A 12-month study in 411 participants alongside a structured lifestyle programme reported placebo-corrected loss of 5.6 ± 2.1% and 6.8 ± 2.3% in the two regimens that held.
Does adding an amylin analog to semaglutide help?
REDEFINE 1 reported −20.4% at week 68 for coadministered cagrilintide and semaglutide against −3.0% on placebo in 3,417 adults. That trial did include 302-participant semaglutide-alone and cagrilintide-alone arms, but the coprimary comparison reported in the published abstract is combination against placebo — so treating the difference from a separate semaglutide trial as the amylin contribution is a cross-trial subtraction, not a within-trial result.
Are amylin analogs better tolerated than GLP-1 drugs?
That is the hypothesis the class is being developed on, and it is not yet answered by a phase 3. A phase 1 report for petrelintide described nausea in 16.7% to 33.3% of participants against 16.7% on placebo in its multiple-ascending-dose part. Phase 1 tolerability figures come from small groups and are a weak predictor of phase 3 rates.
How long does a long-acting amylin analog last?
Petrelintide's phase 1 programme reported a half-life of approximately 10 days, against approximately 48 minutes on the label for the approved short-acting amylin analog. That difference is what makes weekly dosing possible and is the main thing separating this generation from the last.
References
- DailyMed, U.S. National Library of Medicine (2026). SYMLINPEN (pramlintide acetate) injection — prescribing information, Clinical Pharmacology. DailyMed Structured Product Label. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4aea30ff-eb0d-45c1-b114-3127966328ff
- Brændholt Olsen M, Griffin J, Hövelmann U, et al. (2026). Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Petrelintide for Weight Management: Two Randomized, Controlled Phase 1 Trials. Diabetes, Obesity and Metabolism. https://pubmed.ncbi.nlm.nih.gov/42017294/
- Aronne L, Fujioka K, Aroda V, et al. (2007). Progressive reduction in body weight after treatment with the amylin analog pramlintide in obese subjects: a phase 2, randomized, placebo-controlled, dose-escalation study. The Journal of Clinical Endocrinology and Metabolism. https://pubmed.ncbi.nlm.nih.gov/17504894/
- Smith SR, Aronne LJ, Burns CM, et al. (2008). Sustained weight loss following 12-month pramlintide treatment as an adjunct to lifestyle intervention in obesity. Diabetes Care. https://pubmed.ncbi.nlm.nih.gov/18753666/
- Lau DCW, Erichsen L, Francisco AM, et al. (2021). Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial. The Lancet. https://pubmed.ncbi.nlm.nih.gov/34798060/
- Garvey WT, Blüher M, Osorto Contreras CK, et al. (2025). Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. https://pubmed.ncbi.nlm.nih.gov/40544433/
Medical disclaimer: This content is for general educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional before starting, stopping, or changing any treatment.
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