New Dual-Action Weight Loss Drug Amycretin Cuts Body Weight by Up to 24%
A phase 1b/2a trial shows once-weekly amycretin, a novel GLP-1 and amylin receptor co-agonist, drove up to 24% weight loss over 36 weeks.
Summary
Amycretin is a new injectable drug that simultaneously activates two appetite-regulating pathways — GLP-1 and amylin receptors — in a single molecule. A randomized, placebo-controlled phase 1b/2a trial involving 125 adults with overweight or obesity tested weekly subcutaneous injections over 20–36 weeks. At the highest dose (60 mg), participants lost an average of 24.3% of body weight versus just 1.1% with placebo. Even lower doses produced significant losses. Side effects were mostly mild-to-moderate gastrointestinal symptoms, consistent with other drugs in this class. These results position amycretin as a potentially powerful next-generation obesity treatment warranting larger trials.
Detailed Summary
Obesity remains a leading driver of metabolic disease and reduced healthspan, making effective pharmacological interventions a priority in longevity medicine. The incretin drug class — exemplified by GLP-1 receptor agonists like semaglutide — has already transformed obesity treatment, but researchers are now exploring multi-receptor strategies to amplify weight loss further.
Amycretin is a first-of-its-kind unimolecular agent that co-activates both GLP-1 receptors and amylin receptors within a single compound. GLP-1 slows gastric emptying and reduces appetite via the brain; amylin complements this by suppressing glucagon and independently signaling satiety. Combining both pathways in one molecule may produce additive or synergistic weight reduction.
This phase 1b/2a trial enrolled 125 adults (BMI 27–39.9 kg/m²) and randomized them to once-weekly subcutaneous amycretin or placebo across five study parts testing different doses and durations. At 60 mg over 36 weeks, amycretin produced a mean body weight reduction of 24.3% versus 1.1% for placebo. The 20 mg dose yielded 22.0% loss, 5 mg yielded 16.2%, and even the lowest maintenance dose of 1.25 mg produced 9.7% reduction — all statistically significant versus placebo.
The safety profile was consistent with GLP-1 class drugs: gastrointestinal adverse events (nausea, vomiting) were the most common, but predominantly mild to moderate and resolved by study end. A notable proportion of participants withdrew, though most discontinuations were unrelated to adverse events.
These findings suggest amycretin may offer weight loss efficacy exceeding currently approved therapies. However, the study was single-center, short-term, and lacked cardiovascular or metabolic endpoint data. Larger, longer trials are needed before clinical application, and the high dropout rate warrants scrutiny.
Key Findings
- At 60 mg over 36 weeks, amycretin reduced body weight by 24.3% vs 1.1% for placebo.
- All four tested doses produced statistically significant weight loss versus placebo.
- Gastrointestinal side effects were most common but largely mild-to-moderate and transient.
- Amycretin combines GLP-1 and amylin receptor activation in a single injectable molecule.
- Results support advancement to larger phase 2/3 trials for obesity treatment.
Methodology
Randomized, placebo-controlled, single-center phase 1b/2a trial (n=125) testing subcutaneous amycretin across five parts with single and multiple ascending doses ranging from 0.3 mg to 60 mg. Treatment durations ranged from 20 to 36 weeks with once-weekly dosing; participants and investigators were masked to allocation.
Study Limitations
The study was conducted at a single center in the US with a relatively small sample and short follow-up, limiting generalizability. No cardiovascular, glycemic, or long-term safety endpoints were assessed. High dropout rates and Novo Nordisk funding introduce potential bias considerations.
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