Amylin: the other fullness hormone behind the next weight-loss drugs
After GLP-1, drugmakers are betting on a second hormone that tells your brain you have eaten enough. Here is what amylin does and which medicines are coming.
Almost every weight-loss medicine you have heard of, from Wegovy to Zepbound to the new pills, is built around one hormone: GLP-1. The next wave is built around a different one, called amylin. Most of the big drugmakers in the field now have an amylin medicine in development, and the first could be approved in the coming months.
What is amylin?
Amylin is a hormone made by the same cells in the pancreas that make insulin. When you eat, they release both together. Insulin moves sugar from your blood into your cells. Amylin does three helpful things at the same time: it tells the brain you have eaten enough, it slows how quickly food leaves your stomach so you stay full longer, and it stops the body releasing extra sugar after a meal.
Think of GLP-1 and amylin as two different messengers carrying the same message, "I'm full", along slightly different routes to the brain. That is why researchers think combining them, or using amylin on its own, could work well.
This is not a brand-new idea
An amylin copy called pramlintide (Symlin) has been approved for diabetes since 2005. It never caught on, because it lasts only a few hours and has to be injected before every meal. The breakthrough now is long-acting versions that last a whole week, so one injection a week is enough.
Why the excitement?
Two reasons. First, amylin adds to GLP-1: in trials, the combination produces more weight loss than either one alone. Second, amylin medicines on their own seem gentler on the stomach. Early studies suggest less nausea and vomiting, which matters because stomach side effects are the main reason people quit GLP-1 medicines. Some researchers also think amylin may lead to weight loss with a bit less muscle loss, but that has not been proven yet.
The amylin medicines to watch
CagriSema (Novo Nordisk): closest to approval
CagriSema combines semaglutide, the medicine in Wegovy, with cagrilintide, a long-acting amylin copy, in one weekly injection. In its main trial, people lost 22.7% of their body weight on average over 68 weeks, more than with semaglutide alone. In a head-to-head trial against tirzepatide, however, it came up short. Novo Nordisk has applied for FDA approval, and a decision is expected before the end of 2026. If approved, it will be the first amylin-based obesity medicine.
Petrelintide (Zealand Pharma and Roche): amylin on its own
Petrelintide is a pure amylin medicine. In a 42-week trial published in September 2026, people lost up to 10.7% of their weight, versus 1.7% on placebo. That is less than the strongest GLP-1 drugs, but the side effects stood out: 20% reported nausea (versus 6% on placebo), mostly mild, and only about 1% stopped because of stomach problems. It is now moving into larger Phase 3 trials.
Eloralintide (Eli Lilly): alone and paired with Zepbound
On its own, eloralintide produced up to 12.3% weight loss over 48 weeks. Paired with tirzepatide, the medicine in Zepbound, it produced 23.3% weight loss in people with type 2 diabetes, compared with 14.8% on tirzepatide alone. The catch: more people on the combination stopped because of side effects. Lilly plans to start Phase 3 trials of a combined injection by the end of 2026.
Amycretin (Novo Nordisk): two hormones in one molecule
Rather than mixing two medicines, amycretin is a single molecule that acts on both the GLP-1 and the amylin receptor. In an early trial, people lost about 22% of their weight in 36 weeks, and weight loss had not yet levelled off when the study ended. Novo Nordisk is taking both an injection and a pill version into Phase 3 trials.
What this means for you
For now, nothing changes: the approved GLP-1 medicines remain the options available. But within a few years, people may be able to choose between a stronger combination for maximum weight loss and a gentler amylin-only option for those who could not tolerate GLP-1 side effects. More choice should mean more people find a medicine they can stay on.
Read more about CagriSema and other medicines under review in our Peptides section.
This article is general information, not medical advice. Figures come from published trial results and company announcements available on October 10, 2026. Talk to a licensed clinician before starting, stopping or changing any medication.