AmycretinResearch, Evidence & Safety Profile

Amycretin (international nonproprietary name zenagamtide, development code NN 9487) is an investigational peptide drug developed by Novo Nordisk A/S. It is a single molecule that operates as a GLP-1 receptor agonist and amylin receptor agonist — distinct from fixed-dose combinations such as CagriSema, which combines cagrilintide (an amylin analog) with semaglutide (a GLP-1 agonist) as two separate molecules. Amycretin is being developed in both subcutaneous (once-weekly) and oral (once-daily) formulations.

Phase 2 results have been disclosed for both formulations. In adults with overweight or obesity, the subcutaneous formulation reported approximately 22% body weight reduction at 36 weeks in Phase 1b/2a dose-finding, and the oral formulation reported approximately 13.1% weight loss at 12 weeks in early data with a confirmatory Phase 2 readout showing 10.4% weight loss at 12 weeks versus 1.5% placebo. In adults with type 2 diabetes, the oral formulation reported up to 14.5% weight loss at 36 weeks with 89% of participants achieving HbA1c below 7% — figures that, if replicated in Phase 3, would represent leading combined glycemic and weight-loss outcomes for an oral therapy.

On the basis of these Phase 2 results, Novo Nordisk announced that the Phase 3 REDEFINE program for amycretin would launch in the first quarter of 2026 across both formulations and both indications (obesity and type 2 diabetes). REDEFINE is a multi-trial pivotal program intended to support a New Drug Application; specific trial designs and endpoints are being registered as enrollment opens.

As of May 2026, amycretin is not approved by the U.S. Food and Drug Administration or any other regulatory agency for any indication. It is in active Phase 3 clinical development.

Regulatory caution: Amycretin is an investigational compound produced through company-controlled manufacturing. It is not legally compoundable in the United States. Any source claiming to supply amycretin outside of an approved clinical trial should be regarded with serious skepticism — identity, purity, and safety of such products cannot be verified.

Amycretin is engineered as a single molecule that activates two distinct receptor systems implicated in appetite regulation and metabolic control. The dual-agonist design is intended to deliver complementary satiety signaling within a single chemical entity, in contrast to fixed-dose combinations that pair two separate molecules.

• GLP-1 receptor activation: Glucagon-like peptide-1 receptor agonism slows gastric emptying, enhances glucose-dependent insulin secretion, suppresses post-prandial glucagon, and signals through hindbrain and hypothalamic centers to promote satiety. This is the mechanism shared with semaglutide, tirzepatide, and retatrutide.
• Amylin receptor activation: Amylin receptors are heterodimeric complexes of the calcitonin receptor with receptor activity-modifying proteins (RAMPs). Activation slows gastric emptying, dampens post-meal glucagon, and signals satiety through distinct hindbrain circuits. A growing evidence base suggests amylin agonism may also restore central nervous system sensitivity to leptin — a mechanism that GLP-1 monotherapy does not directly target. This is the mechanism shared with petrelintide and the cagrilintide component of CagriSema.
• Unimolecular dual agonism: Because amycretin is a single chemical entity rather than a co-formulation, pharmacokinetic behavior is unified — there is one absorption profile, one half-life, one distribution. This simplifies dosing relative to combinations and may differ pharmacologically from administering two separate amylin and GLP-1 agonists.
• Oral delivery via SNAC technology: The oral formulation of amycretin uses SNAC (sodium N-[8-(2-hydroxybenzoyl)amino]caprylate), the same absorption-enhancer that enables oral semaglutide (Rybelsus). SNAC transiently raises gastric pH and complexes with the peptide to support gastric absorption of a molecule that would otherwise be degraded by digestive enzymes.

The net result of GLP-1 + amylin dual agonism is delayed gastric emptying, glucose-dependent insulin release, dampened glucagon, restored leptin signaling, and reduced caloric intake — a profile that overlaps mechanistically with the incretin/amylin combination class but is consolidated within a single molecule.

The following potential benefits are based on Phase 2 human clinical trial data disclosed by Novo Nordisk through company communications and conference presentations. Phase 3 REDEFINE data does not yet exist. Phase 2 figures should be interpreted with appropriate caution — weight-loss magnitude in incretin and amylin trials commonly evolves between Phase 2 and Phase 3.

• Body weight reduction (subcutaneous, obesity): Phase 1b/2a reported approximately 22% body weight reduction at 36 weeks in the subcutaneous formulation. This figure is among the highest in the incretin/amylin class, comparable to published Phase 2 retatrutide data (24.2% at 48 weeks) and Phase 3 tirzepatide data (~20% at 72 weeks). Direct comparison is imperfect — trial designs, populations, dose escalation schedules, and durations differ.
• Body weight reduction (oral, obesity): Phase 2 reported 10.4% weight loss at 12 weeks versus 1.5% placebo. Twelve-week readouts substantially understate longer-term loss in this class; a longer-duration Phase 2 or Phase 3 readout will be a more meaningful comparator.
• Combined weight and glycemic outcomes (oral, type 2 diabetes): Phase 2 in type 2 diabetes reported up to 14.5% weight loss at 36 weeks with 89% of participants achieving HbA1c below 7%. The combination of leading-magnitude weight loss and strong HbA1c response within an oral formulation is the headline pharmacological feature of amycretin and the principal strategic rationale for Phase 3 advancement in both obesity and diabetes indications.
• Mechanistic complementarity: Unimolecular GLP-1 + amylin agonism activates two distinct satiety pathways within a single molecule. The mechanistic argument is that combined signaling may produce additive effects beyond what monotherapy in either class can deliver. Whether this translates to superior real-world outcomes over comparator therapies will require head-to-head trials, which are not yet planned.
• Oral administration as a barrier-reduction strategy: Daily oral administration may improve adherence and broaden the addressable population relative to weekly injectables, particularly among patients reluctant to self-inject. Oral peptide therapy has historically been bioavailability-limited; SNAC technology is the principal vehicle that has made this clinically tractable.

Phase 3 readouts are the next meaningful data point. REDEFINE is expected to characterize efficacy and safety in larger populations over longer durations than Phase 2, and is the basis on which an NDA submission would be supported.

Amycretin's safety profile, as reported from Phase 2, is consistent with the GLP-1 receptor agonist class. Phase 3 data does not yet exist; long-term safety remains uncharacterized.

• Gastrointestinal effects: Nausea, vomiting, diarrhea, and other gastrointestinal adverse events are commonly reported across GLP-1 and dual-agonist therapies and have been observed with amycretin in Phase 2. As with related compounds, GI events are most prominent during dose escalation and typically diminish at maintenance dosing.
• Injection site reactions (subcutaneous formulation): Mild injection site reactions (redness, irritation) have been reported. These are generally transient and self-limiting.
• Hypoglycemia: GLP-1 agonism and amylin agonism are largely glucose-dependent in their insulin-secretagogue effects. Risk of hypoglycemia from amycretin alone is low; risk increases substantially when combined with insulin or sulfonylureas. The native amylin analog pramlintide (Symlin) carries an FDA boxed warning for severe hypoglycemia in this combination — a class-level signal worth respecting.
• Pancreatitis and gallbladder disease: GLP-1 receptor agonists as a class carry post-marketing reports of pancreatitis and gallbladder events. Whether these signals will be replicated for amycretin in Phase 3 and post-market surveillance is unknown.
• Thyroid C-cell tumors: GLP-1 receptor agonists carry an FDA boxed warning for the risk of thyroid C-cell tumors based on rodent data. The relevance to humans remains debated. Whether amycretin carries this class-level labeling will be determined during regulatory review.
• Long-term safety: Amycretin is in Phase 3 with no marketed history. Long-term safety, pregnancy and lactation safety, and effects in older adults and people with renal/hepatic impairment will be characterized through Phase 3 and post-market surveillance.

Any decision about whether a GLP-1/amylin therapy is appropriate for a given individual is a clinical decision that should be made with a prescribing clinician. Patient-specific contraindications (personal or family history of medullary thyroid carcinoma, MEN 2, history of pancreatitis, etc.) need to be evaluated individually.

Disclaimer: Amycretin is investigational and not approved for any indication. The following information reflects publicly disclosed clinical trial design for educational purposes only. These are not recommendations for self-administration.

Amycretin is being developed in two formulations:

• Subcutaneous (once-weekly): Phase 1b/2a used a multi-step dose escalation protocol over approximately 36 weeks. Specific maintenance dose magnitudes have been disclosed at the investor and conference level; full peer-reviewed publication of dose-response is pending Phase 2 manuscript release.
• Oral (once-daily): Uses SNAC absorption-enhancer technology (the same approach as oral semaglutide / Rybelsus). The oral formulation has been studied in Phase 2 in both obesity (12-week readout) and type 2 diabetes (36-week readout) with progressive dose escalation.

Phase 3 REDEFINE dose selection will follow standard regulatory practice — anchored on the Phase 2 dose-response data and intended to characterize efficacy and safety across a clinically relevant range. Final approved dosing, if and when granted, will be specified by the regulatory label.

As of May 2026, amycretin has one of the more advanced clinical data sets of any unimolecular GLP-1/amylin co-agonist in development. Several Phase 2 readouts have been disclosed across both formulations and both indications.

• Phase 1b/2a obesity (subcutaneous): Reported approximately 22% body weight reduction at 36 weeks in the highest-dose arm. This dose-finding work established proof-of-concept for unimolecular GLP-1 + amylin agonism and supported advancement to expanded Phase 2 and Phase 3 programs.
• Phase 2 obesity (oral): Reported 10.4% weight loss at 12 weeks versus 1.5% placebo in confirmatory Phase 2. Earlier readouts noted 13.1% at 12 weeks in dose-finding cohorts. Twelve-week readouts substantially understate longer-term loss in this class.
• Phase 2 type 2 diabetes (oral): Reported up to 14.5% weight loss at 36 weeks with 89% of participants achieving HbA1c below 7%. The combined weight-loss and glycemic-control profile is one of the strongest reported for an oral therapy.
• Phase 3 REDEFINE program (announced Q1 2026): Novo Nordisk announced advancement to Phase 3 in both formulations and both indications in the first quarter of 2026. REDEFINE is a multi-trial pivotal program; specific trial designs, sizes, and primary endpoints will be disclosed at trial registration.
• Strategic positioning: Amycretin is one of multiple GLP-1/amylin combination strategies in late-stage development across the field. Distinct approaches include the two-molecule fixed-dose combination (CagriSema), single-molecule co-agonism (amycretin), and combinations of an amylin analog with an unrelated incretin (e.g., petrelintide + CT-388). Comparative head-to-head data between these strategies does not yet exist.

The amylin class has long-standing pharmacological proof-of-concept through pramlintide (Symlin), an approved diabetes adjunct since 2005. The GLP-1 class has extensive marketed history through semaglutide, tirzepatide, and others. Amycretin is the first unimolecular GLP-1/amylin co-agonist to reach Phase 3.

As of May 2026, amycretin is an investigational new drug (IND) in active Phase 3 clinical development under the REDEFINE program. It has not received FDA approval, EMA approval, or approval from any other regulatory agency for any indication.

• United States: Investigational. Available only within approved clinical trial protocols. Not compoundable — amycretin is a proprietary peptide produced through company-controlled manufacturing, not a generic peptide that compounding pharmacies can legally replicate. The April 2026 FDA proposal to exclude semaglutide, tirzepatide, and liraglutide from 503B outsourcing-facility bulk compounding (a separate regulatory action) reinforces that proprietary investigational and approved GLP-1 class compounds are not appropriate compounding targets.
• European Union: No regulatory status established. Phase 3 REDEFINE is being designed for global development.
• Off-label or grey market access: As a proprietary investigational drug, unauthorized access should be extremely limited. Any source claiming to supply amycretin outside of a clinical trial should be regarded with serious skepticism — identity, purity, and safety cannot be verified, and the legal exposure to suppliers and purchasers is significant.
• Expected timeline: Phase 3 REDEFINE launching Q1 2026. Phase 3 obesity trials in this class commonly run 68–80 weeks for primary efficacy endpoints, plus enrollment and follow-up. NDA filing timing depends on trial design; market availability would not be expected before 2028 at the earliest, and is speculative pending Phase 3 outcomes and regulatory review.