What Is Petrelintide? The Long-Acting Amylin Analogue Being Developed for Obesity

GLP-1 medicines have dominated obesity research for several years.

But another hormone pathway is now becoming increasingly important: amylin.

One of the most advanced compounds targeting this pathway is petrelintide, a long-acting amylin analogue being developed as a once-weekly treatment for obesity and overweight.

Unlike GLP-1 receptor agonists, petrelintide is designed around a different biological signal involved in satiety and energy regulation.

And as of 2026, it has progressed into Phase 3 clinical development. (Zealand Pharma⁠)

What Is Petrelintide?

Petrelintide, previously known as ZP8396, is an investigational long-acting analogue of the naturally occurring hormone amylin.

It is being developed by Zealand Pharma in collaboration with Roche.

Petrelintide is designed for once-weekly subcutaneous administration.

Its purpose is to reproduce some of the biological effects of natural amylin while lasting substantially longer in the body. (Zealand Pharma⁠)

What Is Amylin?

Amylin is a hormone naturally produced by pancreatic beta cells.

It is released alongside insulin after food is consumed.

Amylin contributes to the body’s regulation of:

• satiety
• food intake
• gastric emptying
• post-meal glucose control
• communication between the digestive system and brain

In simple terms, amylin helps signal that enough food has been consumed.

This makes it a logical target for obesity research.

How Is Petrelintide Different From GLP-1 Drugs?

GLP-1 receptor agonists such as semaglutide primarily act through the GLP-1 receptor.

Petrelintide targets the amylin pathway instead.

The two systems overlap in some of their effects, particularly reduced food intake and increased satiety, but they are biologically distinct.

That distinction is important because researchers are trying to determine whether amylin-based therapies can provide meaningful weight reduction while producing a different tolerability profile.

Zealand Pharma has specifically positioned petrelintide as a potential alternative or complementary approach to incretin-based medicines. (Zealand Pharma⁠)

Why Is Amylin Becoming Such a Major Research Area?

The success of GLP-1 therapies demonstrated that modifying appetite-regulating hormone pathways can produce substantial metabolic effects.

Researchers are now investigating whether similar or complementary benefits can be achieved through other hormones.

Amylin has become particularly interesting because it appears to influence satiety through mechanisms that are not identical to GLP-1.

This raises several possibilities.

Researchers want to know whether amylin-based drugs could:

• produce substantial weight reduction
• improve tolerability
• preserve more lean tissue
• work in people who do not tolerate GLP-1 therapies well
• combine effectively with GLP-1 or GIP-based medicines

Petrelintide is currently one of the leading candidates attempting to answer those questions.

What Did the Phase 2 Trial Show?

A large Phase 2 study called ZUPREME-1 investigated once-weekly petrelintide in adults with obesity or overweight without type 2 diabetes.

The trial randomised 493 participants, with 485 receiving at least one dose of treatment.

Participants received different maintenance doses of petrelintide or placebo.

At 28 weeks, average weight reductions across the petrelintide groups ranged from approximately 7.9% to 9.8%, compared with around 1.7% with placebo.

Weight reduction continued through week 42, reaching up to approximately 10.7% in some groups. (PubMed⁠)

These results provided strong enough evidence for the programme to advance further.

Did Higher Doses Produce More Weight Loss?

Interestingly, not in a straightforward dose-dependent pattern.

The 5 mg group produced one of the strongest average reductions at week 28, while higher doses did not dramatically outperform it.

That is important because obesity-drug development is not simply about finding the largest possible dose.

Researchers also need to identify the dose providing the best balance between:

• effectiveness
• tolerability
• ease of dose escalation
• long-term adherence

Later Phase 3 trials should provide a clearer picture of the optimal dose.

What Were the Side Effects?

The most commonly reported adverse event in the Phase 2 trial was nausea.

Around 20% of participants receiving petrelintide experienced nausea compared with approximately 6% receiving placebo.

Vomiting was relatively uncommon, occurring in around 3% of participants receiving petrelintide.

Rates of diarrhoea and constipation were also relatively low in the study. (PubMed⁠)

Most importantly, researchers reported that nausea was predominantly mild and occurred particularly during dose escalation.

Could Petrelintide Be Better Tolerated Than GLP-1 Drugs?

This is one of the major questions surrounding the compound.

Early results have generated interest because gastrointestinal adverse effects appeared relatively modest compared with what can occur with some incretin-based therapies.

However, it would be premature to conclude that petrelintide is definitively better tolerated.

Different trials involve different populations, dosing schedules and study designs.

Direct comparative trials would be needed before firm conclusions could be made.

What About Lean Muscle?

This is another reason amylin analogues are attracting attention.

One concern during significant weight reduction is the loss of lean tissue alongside fat mass.

Preclinical and early clinical observations have raised the possibility that amylin-based approaches may preserve a greater proportion of lean mass than some other strategies.

Zealand Pharma specifically identifies potential lean-mass preservation as an area of interest for petrelintide. (Zealand Pharma⁠)

But this remains something that needs to be confirmed more clearly in larger clinical trials.

Has Petrelintide Reached Phase 3?

Yes.

Petrelintide has now progressed into Phase 3 development.

One Phase 3 study, ZUPREME-4, is recruiting participants with overweight or obesity and type 2 diabetes.

The trial plans to enrol approximately 600 participants and compare once-weekly petrelintide with placebo alongside reduced-calorie diet and increased physical activity.

The estimated primary completion date is in 2028. (ClinicalTrials⁠)

That places petrelintide considerably further along the development pathway than many experimental peptides discussed online.

What About People With Type 2 Diabetes?

A separate Phase 2 programme called ZUPREME-2 has investigated petrelintide in people with overweight or obesity and type 2 diabetes.

Zealand Pharma reported topline results from that programme in October 2026. (Zealand Pharma⁠)

The broader Phase 3 programme is now expanding this research in people with metabolic disease.

Could Petrelintide Be Combined With GLP-1 Drugs?

Yes, and this may ultimately become one of the most important areas of petrelintide development.

Zealand Pharma and Roche are developing a fixed-dose combination of petrelintide with CT-388, an experimental dual GLP-1/GIP receptor agonist.

The concept is to combine:

amylin signalling from petrelintide

with

GLP-1/GIP signalling from CT-388.

The companies hope this could provide greater weight reduction for individuals requiring more than amylin monotherapy. (Zealand Pharma⁠)

Why Combine Different Hormone Pathways?

Obesity is regulated by multiple overlapping biological systems.

Targeting several pathways simultaneously may potentially produce stronger effects than targeting one pathway alone.

This is already evident with compounds such as tirzepatide, which activates both GIP and GLP-1 receptors.

The next generation of obesity medicines is increasingly exploring combinations involving:

• GLP-1
• GIP
• glucagon
• amylin
• other metabolic pathways

Petrelintide could therefore become part of a broader shift toward multi-pathway metabolic therapies.

Is Petrelintide a Peptide?

Yes.

Petrelintide is a peptide-based analogue of the human hormone amylin.

It has been chemically engineered to provide prolonged activity suitable for once-weekly administration.

This makes it a genuine peptide therapeutic candidate rather than simply a small molecule acting on a peptide receptor.

Is Petrelintide Approved?

No.

Petrelintide remains an investigational medicine.

It has not been approved for routine clinical use by major regulatory authorities.

Even though it has now reached Phase 3 trials, further research is still required to establish:

• long-term effectiveness
• long-term safety
• optimal dose
• cardiovascular outcomes
• effects on body composition
• effects in different populations
• comparative effectiveness against existing treatments

Why Is Petrelintide Important?

Petrelintide matters because it represents something broader than one new obesity drug.

It demonstrates how metabolic drug research is beginning to move beyond GLP-1 alone.

The first major wave focused on GLP-1.

The second wave introduced combinations such as GLP-1/GIP and GLP-1/glucagon.

Amylin may become another major component of this evolving field.

The Bottom Line

Petrelintide is an investigational long-acting amylin analogue designed for once-weekly administration.

A large Phase 2 trial involving almost 500 treated participants reported average weight reductions approaching 10% by week 28, with weight continuing to decline through week 42. (PubMed⁠)

The compound has now advanced into Phase 3 clinical development, including trials in people with overweight or obesity and type 2 diabetes. (ClinicalTrials⁠)

What makes petrelintide particularly interesting is not simply its effect on body weight.

It represents a different hormone pathway from GLP-1 and could eventually become either an alternative or a complementary component of future metabolic therapies.

Whether those possibilities translate into real clinical advantages will depend on the results of the ongoing Phase 3 programme.

For researchers following the next generation of peptide-based metabolic medicines, petrelintide is one of the most important compounds to watch.

This article is for research and educational purposes only. Petrelintide remains investigational and is not presented as an approved or established treatment.