What is amycretin, and how much weight loss does it cause?

The short answer

Amycretin is Novo Nordisk's first-in-class, unimolecular GLP-1 and amylin receptor agonist — a single molecule hitting two appetite pathways, available in both injectable and oral forms. In early-phase trials, injectable amycretin produced up to about 22% body-weight loss at 36 weeks, and the oral version about 13% at just 12 weeks. It's now in Phase 3; it is not yet approved.

Evidence tier: Tier 1 for the published early-phase trial results; Tier 2 for cross-trial comparisons. Educational content, not medical advice.

The key points:

• Two pathways, one molecule: GLP-1 + amylin receptor agonism
• Injectable: up to ~22% weight loss at 36 weeks (Phase 1b/2a)
• Oral: ~13% at 12 weeks — a pill rivaling injectables
• Still early — Phase 3 underway, not approved; trial data are early-phase

For the drug-class background, see the GLP-1 complete guide.

What is amycretin?

Evidence tier: 2 — established pharmacology.

Amycretin is an investigational obesity and type 2 diabetes drug from Novo Nordisk, described as a unimolecular GLP-1 and amylin receptor agonist — meaning one molecule activates both the GLP-1 receptor and the amylin receptor. The headline feature is that it's being developed in both subcutaneous (injectable) and oral forms, which is unusual and commercially significant: an oral pill that approaches injectable-level weight loss would remove the needle barrier that keeps some people away from GLP-1 therapy.

The reason the dual mechanism matters is that amylin is a genuinely different lever from GLP-1. GLP-1 reduces appetite and slows gastric emptying; amylin (a hormone co-secreted with insulin) promotes satiety through separate central pathways and may help preserve the response to weight loss over time. Novo already pursues amylin via cagrilintide — the partner molecule in CagriSema — but amycretin folds both activities into a single molecule rather than combining two drugs (CagriSema deep-dive). That's the conceptual leap: not GLP-1 plus a second injection, but one agent doing two jobs, in a pill or a shot.

How much weight loss does amycretin cause?

Evidence tier: 1 — published early-phase randomized trials.

The early data are what generated the excitement. In a Phase 1b/2a randomized controlled study of once-weekly subcutaneous amycretin in adults with overweight or obesity, treatment produced significantly greater weight loss than placebo across the dose range, reaching an estimated ~22% at 36 weeks at the top dose — with roughly 9.7% by 20 weeks and 16.2% by 28 weeks at intermediate doses (Lancet, PMID 40550231). For context, ~22% in 36 weeks is a steep trajectory that hadn't plateaued, which is part of why it drew comparisons to the most effective agents in development.

The oral version is arguably the bigger story. In a first-in-human Phase 1 study, once-daily oral amycretin produced a mean weight change of about −10.4% and −13.1% at 12 weeks (at the higher dose regimens) versus −1.2% with placebo (Lancet, doi:10.1016/S0140-6736(25)01176-6). A roughly 13% reduction in just 12 weeks from a pill is striking, since oral peptide delivery has historically been limited by poor absorption. Both results, though, carry the same essential caveat: these are early-phase trials — small, short, dose-finding — and early-phase weight-loss curves routinely look steeper than what larger, longer Phase 3 trials confirm. The numbers are real and published; they're just not yet the final word.

Why is an oral GLP-1/amylin pill a big deal?

Evidence tier: 2 — mechanistic and market reasoning.

Most of the strongest obesity drugs are injectables, and the few oral options have trade-offs. Oral semaglutide (Rybelsus) works but requires strict fasting-and-water dosing rules because peptide absorption through the gut is inefficient and easily disrupted — the same absorption and interaction issues we cover in oral GLP-1 absorption and CYP3A4. An oral drug that delivers double-digit weight loss while also engaging the amylin pathway would be a meaningful step beyond what's currently available in pill form.

There's also a supply and access angle. Injectable manufacturing capacity has been a real constraint on the GLP-1 market, and pills are generally easier to scale and distribute. So a successful oral amycretin wouldn't just be more convenient for patients — it could ease the bottlenecks that have driven shortages and fueled the gray market. That said, "would be" is the operative phrase: the oral data are from a 12-week first-in-human study, and oral bioavailability, food effects, and real-world dosing reliability all still need to be established at scale. The promise is large; the proof is early.

It's worth being precise about why oral peptide delivery is hard, because it explains both the achievement and the uncertainty. Peptides are large, fragile molecules that the digestive system is designed to break down, so only a small and variable fraction normally survives to be absorbed. Getting a meaningful, consistent dose into the bloodstream from a pill is a genuine pharmaceutical challenge — which is why oral semaglutide needs its rigid dosing ritual and still delivers less than the injectable. If amycretin's oral form holds up in larger trials, it would suggest Novo has made real progress on that absorption problem. If it doesn't, the oral version may end up meaningfully weaker than the injectable. Both outcomes are still on the table.

How does amycretin compare to tirzepatide, retatrutide, and CagriSema?

Evidence tier: 2 — cross-trial comparison, not head-to-head.

The next-generation obesity field now splits by receptor combination. Tirzepatide is GLP-1 + GIP; retatrutide is a GLP-1 + GIP + glucagon triple agonist; survodutide is GLP-1 + glucagon; and amycretin is GLP-1 + amylin in one molecule (next-gen multi-agonists overview; survodutide explained). CagriSema reaches the amylin pathway too, but as a co-formulation of two molecules (cagrilintide + semaglutide) rather than a single unimolecular agent.

The critical caveat is the same one that applies across this whole category: these are cross-trial comparisons, not head-to-head trials. Amycretin's ~22% came from a small Phase 1b/2a study; tirzepatide and semaglutide figures come from large Phase 3 programs. Comparing an early-phase number to a mature Phase 3 number overstates how settled the ranking is — early-phase results tend to look more dramatic. What's fair to say is that amycretin's early efficacy is in the competitive range of the leading agents, and its combination of (a) a distinct amylin mechanism and (b) a viable oral form is what makes it genuinely differentiated rather than just another GLP-1 variant.

What's the current status and what are the risks?

Evidence tier: 1–2 — trial safety plus regulatory status.

On tolerability, amycretin so far looks like the incretin/amylin class: predominantly gastrointestinal side effects (nausea, vomiting), dose-related and managed with gradual escalation. A Phase 2 trial in type 2 diabetes reported significant weight loss and HbA1c reduction with a safety profile consistent with other incretin- and amylin-based therapies. As always, longer and larger trials are where rarer or longer-term safety signals would emerge, and none of that is settled yet.

On status, the essential facts: amycretin is investigational and not approved anywhere, and Novo Nordisk has advanced it to Phase 3 for obesity based on the published early-phase results, with diabetes development continuing. That means you cannot get amycretin by prescription, and anything sold online as "amycretin" is gray-market and unverified — almost certainly not the real, characterized compound, and carrying the authenticity, dosing, and contamination risks detailed in spotting counterfeit peptides. The honest framing is that amycretin is one of the most promising obesity drugs in development — a name worth tracking closely — but not something to source or self-experiment with today.

Limitations

This is educational content, not medical advice.

• All efficacy data are early-phase (Phase 1/1b/2a) — short, small, and dose-finding; Phase 3 is ongoing.
• Early-phase weight-loss curves often look steeper than what larger Phase 3 trials confirm.
• Cross-trial comparisons aren't head-to-head — don't over-read amycretin vs tirzepatide/retatrutide numbers.
• Not approved anywhere — online "amycretin" is gray-market and almost certainly not genuine.
• Oral bioavailability and food effects still need to be established at scale.
• Marko Maal, MSc Pharmacy reviewed this article. Reviewer attribution does not constitute a doctor-patient relationship.

The bottom line

Amycretin is Novo Nordisk's first-in-class GLP-1/amylin unimolecular agonist, and it stands out for two reasons: a distinct dual mechanism that adds the amylin satiety pathway to GLP-1, and the fact that it works in both injectable and oral forms. Early-phase trials showed up to ~22% weight loss at 36 weeks (injectable) and ~13% at 12 weeks (oral) — genuinely impressive, but early, small, and short, with Phase 3 still to confirm whether those curves hold. It's investigational and not available by prescription, so any "amycretin" sold online is fake. It belongs high on the watch list for the future of obesity treatment, not in anyone's medicine cabinet yet.

Related on this site

• GLP-1 complete guide
• Next-gen multi-agonists overview
• Survodutide (glucagon/GLP-1) explained
• CagriSema deep-dive
• Oral GLP-1 absorption & CYP3A4
• Our evidence-tier framework

References

• Amycretin, a novel, unimolecular GLP-1 and amylin receptor agonist administered subcutaneously: results from a phase 1b/2a randomised controlled study. Lancet 2025. PMID 40550231 — injectable amycretin, up to ~22% at 36 weeks.
• First-in-human, phase 1, randomised, placebo-controlled study of oral amycretin. Lancet 2025. doi:10.1016/S0140-6736(25)01176-6 — oral amycretin, ~10–13% at 12 weeks.
• Amycretin subcutaneous phase 1b/2a (canonical record). doi:10.1016/S0140-6736(25)01185-7 — full subcutaneous trial report.