Petrelintide is a long-acting amylin analogue from Zealand Pharma, in phase 2 for obesity and partnered with Roche. It is built on the human amylin backbone rather than the rat sequence pramlintide uses, with a lactam bridge replacing the native disulfide and a C20 diacid for albumin binding, giving a half-life of about ten days [1][2]. ⚠️ It is widely described as a selective amylin analogue, and its sponsor's own data show it is not: it is equally potent at the calcitonin receptor [1].
- No serious or severe adverse events across two phase 1 trials
- No anti-drug antibodies in any participant
- Around 8.6 percent weight loss over sixteen weeks with no lifestyle programme
- Formulates at neutral pH, so it can share a syringe with semaglutide
- Nausea in 16.7 to 33.3 percent, against 16.7 percent on placebo
- Injection-site reactions, clustered at doses needing up to three separate injections
- Pulse about 5 bpm below baseline late in treatment
Mechanism
Petrelintide is an acylated analogue of human amylin. Relative to the native hormone it carries about a dozen substitutions, the native disulfide replaced by a lactam bridge, two asparagines deleted, two backbone amides methylated, and a C20 diacid attached at the N-terminus through a linker [1]. The design also lowers the isoelectric point to 4.0, which is what allows formulation at neutral pH and co-formulation with semaglutide without accelerating degradation [1].
⚠️ The selectivity question is where most descriptions of this drug go wrong. Measured in the sponsor's own assay, petrelintide reaches EC50 0.33 nM at human AMY3R and 0.32 nM at the human calcitonin receptor, a ratio of about one [1]. In the same experiment native human amylin was roughly seven-fold amylin-selective. Petrelintide is therefore LESS selective than the hormone it was derived from, and it belongs in the dual amylin and calcitonin receptor class alongside cagrilintide. Zealand does not claim otherwise; its clinical paper describes potent effects on amylin receptors "and the calcitonin receptor" [2], and an unrelated group classifies it plainly as a dual [3].
Two gaps in the pharmacology are worth stating. AMY1R, the receptor eloralintide targets, was never tested. And no binding constants exist at all; everything is functional data [1].
In humans the is about ten days and does not differ between subcutaneous and intravenous routes, with 77 percent , so the long duration comes from albumin binding rather than slow absorption [2].
receptor fingerprint
Amylin 3 receptor (AMY3R)Agonist
Calcitonin receptor (CTR)Agonist
Body weightReducer
Evidencehow good the literature is
Two phase 1 trials and one medicinal-chemistry paper are published; the phase 2 programme is not [1][2].
The multiple-dose trial gave 48 participants sixteen weeks of treatment with no lifestyle intervention. Placebo-adjusted weight change was 3.2 percent at 2.4 mg, 7.0 percent at 4.8 mg and 6.7 percent at 9.0 mg, with waist circumference falling up to 7.6 cm [2].
⚠️ Several limits on that number. It is phase 1, with twelve people per group. The cohort was 79 percent male, entirely white, normoglycaemic, and averaged a body mass index of 29.9, which is the low end of the population these drugs are aimed at. The top cohorts only reached their target dose for six to eight of the sixteen weeks.
The phase 2 trial, ZUPREME, enrolled 493 people for 42 weeks and completed in September 2025 with no results posted and nothing published. Any phase 2 efficacy figure in circulation is therefore press-release material rather than reported data. A second phase 2 in type 2 diabetes and a Roche-sponsored combination trial are underway.
⚠️ One registry trap worth naming: an autism trial sponsored by an unrelated company lists "Placebo (ZP8396)" in its intervention field. It is a data-entry error, not a petrelintide trial.
Dosingtypical ranges, not medical advice
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Safetyrisks and cautions, not medical advice
Not an approved medicine; an investigational drug in phase 2. The published human safety record covers two phase 1 trials and is unusually clean for the class: no serious or severe treatment-emergent adverse events in either study, and one discontinuation, for nausea and vomiting after a third dose [2].
Nausea ran at 16.7 to 33.3 percent against 16.7 percent on placebo, and in the single-dose study appeared only at the two highest doses, so escalation matters [2]. Pulse rate settled about 5 bpm below baseline late in treatment. No participant in either trial developed anti-drug antibodies, which is a meaningful negative for a peptide.
⚠️ A practical limitation that rarely gets mentioned: the highest doses required up to three separate injections per weekly dose, and that is where the injection-site reactions clustered [2].
The tolerability comparisons circulating against GLP-1 drugs are cross-trial rather than head-to-head, and the trial's own authors caution against exactly that comparison [2].
History
Zealand Pharma developed petrelintide as part of a wider effort to build amylin analogues stable enough for weekly dosing, a problem the native hormone makes hard because it aggregates readily. The chemistry programme replaced the aggregation-prone segments and the disulfide bridge, and tuned the isoelectric point specifically so the peptide could be formulated at neutral pH and mixed with semaglutide in one syringe. That co-formulation ambition, rather than standalone use, is much of the commercial thesis. Boehringer Ingelheim scientists appear on the medicinal-chemistry paper, and Roche subsequently entered a partnership, with a phase 2 combination trial against its own incretin candidate.
Subjective profileweighing the evidence above
A credible obesity drug with a genuinely clean phase 1 safety record: no serious or severe adverse events across two trials, and no anti-drug antibodies in anyone. The weight loss, around 8.6 percent over sixteen weeks with no lifestyle programme attached, is respectable for phase 1. The thing to correct is the framing. This is not the selective amylin analogue it is usually called; it hits the calcitonin receptor exactly as hard as the amylin receptor, which puts it in the same mechanistic bucket as cagrilintide rather than opposite it. Also note that 9.0 mg produced no more weight loss than 4.8 mg, so the top of the dose range is not yet earning its place.
Resources
This entry is here for reference.
Research
- 1.Development of Petrelintide: a Potent, Stable, Long-Acting Human Amylin Analogue.
- 2.Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Petrelintide for Weight Management: Two Randomized, Controlled Phase 1 Trials.
- 3.Discovery of BGM1812, a Novel Dual Amylin and Calcitonin Receptor Agonist for Obesity Treatment.
3 listed here; entry last updated August 2026
Reviews
My notesprivate to this device
Limitations of the evidence
- Not selective for amylin over calcitonin, despite being widely described that way
- AMY1R was never tested and no binding constants exist
- Phase 2 completed but unpublished, so no efficacy figure beyond phase 1 is verifiable
- Phase 1 cohort was 79 percent male, entirely white and only mildly overweight
Adverse effects
- Nausea in 16.7 to 33.3 percent, against 16.7 percent on placebo
- Injection-site reactions, clustered at doses needing up to three separate injections
- Pulse about 5 bpm below baseline late in treatment