Amycretin: Novo Nordisk's Single-Molecule GLP-1 + Amylin Dual Agonist

The amylin idea

GLP-1 has been the central appetite-suppressing hormone in obesity pharmacology for two decades, but it is not the only one. Amylin — a small peptide hormone co-secreted with insulin from the pancreas — is another. Amylin slows gastric emptying, suppresses glucagon, and produces satiety signals that work alongside GLP-1 rather than redundantly with it. Pramlintide, the synthetic amylin analog, has been an adjunct diabetes treatment since 2005, and cagrilintide — Novo's longer-acting analog — is in Phase 3 as part of CagriSema.

The case for combining GLP-1 with amylin is that the two pathways converge on appetite from genuinely different angles: GLP-1 acts centrally in the brainstem and hypothalamus on neural appetite circuits, while amylin acts at the area postrema and on gastric motility. Combining them produces deeper weight loss than either alone, and is the rationale for the CagriSema combination.

What amycretin actually is

Amycretin is a single molecule that activates both the GLP-1 and amylin receptors — a true dual agonist rather than a combination of two drugs. The same engineering approach that gave tirzepatide its dual GLP-1/GIP activity is being applied here, just with amylin as the second target instead of GIP.

The advantage of a single-molecule approach over a co-formulated combination is mostly chemistry: one pharmacokinetic profile to manage, one set of manufacturing steps, easier dose-ranging in trials, and simpler regulatory clearance. CagriSema, by contrast, has to manage the joint pharmacology of two molecules dosed together.

Amycretin is being developed in both injectable and oral forms — and the oral form is the more pharmacologically interesting one, because it is a peptide formulation that has shown meaningful efficacy in early trials, unlike Rybelsus where the oral version has substantially reduced potency.

Amycretin vs CagriSema: same biology, different chemistry

Both drugs combine GLP-1 and amylin activity. The difference is how:

• CagriSema: a fixed-dose combination of semaglutide + cagrilintide, dosed together once weekly. Two molecules; two pharmacokinetic profiles. Phase 3 is ongoing.
• Amycretin: a single molecule activating both receptors. One pharmacokinetic profile. Available in both injectable and oral forms.

For patients, this is mostly a chemistry distinction with little bearing on outcomes — both approaches produce GLP-1 + amylin activity. For Novo, amycretin may be the longer-term answer: simpler manufacturing, an oral formulation, and a single molecule to develop further.

Phase 1 results

The Phase 1 data on amycretin, reported in 2024, produced one of the more striking magnitude numbers in early-phase obesity trials:

• Injectable form: approximately 13% mean weight loss at 12 weeks across higher doses.
• Oral form: approximately 13% mean weight loss at 12 weeks at the highest dose tested.
• Tolerability: qualitatively similar to the GLP-1 class — nausea, vomiting, and constipation concentrated in titration.

13% at 12 weeks is unusual for a Phase 1 result. For comparison, semaglutide produces roughly 15% at 68 weeks — so amycretin reaches a meaningful fraction of that magnitude in about a sixth of the time. Two caveats are immediate: Phase 1 trials are small and short, so confidence intervals are wide; and early weight loss does not always project linearly to longer-term magnitudes. Phase 2 and Phase 3 will determine whether the trajectory keeps going.

The oral form: why it matters

The oral amycretin result deserves separate attention. Oral peptides are difficult — peptide bonds are degraded by stomach acid and proteases, and absorption across the gut lining is poor without an enhancer. Rybelsus solved part of the problem for semaglutide using SNAC as an absorption enhancer, but at significant cost: oral semaglutide reaches a much smaller fraction of the bloodstream than injectable, and food timing matters enormously.

The Phase 1 oral amycretin data suggests the formulation may be reaching enough exposure to produce meaningful weight loss — which, if it holds, would be the first oral peptide GLP-1 with magnitudes approaching the injectable form. Combined with Lilly's orforglipron (a small-molecule oral non-peptide), this would mean the obesity-pharmacology landscape gains real oral options through 2027-2028.

Timeline and what to watch

Amycretin Phase 2 trials are underway; Phase 3 has begun for the injectable form. Realistic timeline: Phase 3 readouts late 2027 to 2028, U.S. approval most plausibly 2028-2029. Key questions for Phase 3:

• Whether the Phase 1 magnitude trajectory extends to standard 72-week obesity endpoints.
• Whether the oral form reaches comparable magnitude to the injectable.
• How tolerability compares head-to-head with CagriSema and tirzepatide.

The honest read

Amycretin is interesting for two reasons. The single-molecule dual GLP-1 / amylin design is a cleaner version of the biology that CagriSema combines from two molecules, and may be the long-term successor. And the oral form — if it holds — is one of the more meaningful delivery innovations in the class, alongside orforglipron. Magnitudes from Phase 1 should be treated as suggestive, not predictive; the next two years of readouts will determine whether amycretin is the molecule that replaces semaglutide or just an interesting parallel option.