Weight Loss: Cagrilintide & CagriSema (Amylin Agonist — Novo Nordisk's Next Generation)

Why amylin fills the gap GLP-1 alone cannot close

While semaglutide and tirzepatide have dominated obesity therapy in recent years, Novo Nordisk is already building the next generation with Cagrilintide (AM833): a long-acting amylin receptor agonist that works not through incretin signaling but through the satiety hormone amylin. In its fixed-dose combination as CagriSema (cagrilintide + semaglutide), the therapy achieves weight loss in Phase 3 trials that significantly exceeds semaglutide alone — published in the New England Journal of Medicine (2025) and The Lancet Diabetes & Endocrinology (2026).

Mechanism: How Cagrilintide Works

Cagrilintide is an acetylated amylin analogue with extended half-life (~7–10 days after subcutaneous administration) that binds to amylin receptors (AMY₁, AMY₂, AMY₃). These receptors are found primarily in the area postrema of the brainstem and in the hypothalamus.

The central effects are:

• Satiety signaling via the nucleus of the solitary tract — faster onset of fullness per meal
• Delayed gastric emptying — similar to GLP-1, but through a different receptor
• Reduction of postprandial glucagon secretion — hepatic gluconeogenesis is dampened
• Mild inhibition of the food-reward loop in the mesolimbic system (preclinical)

Compared with GLP-1 agonists, the mechanism is therefore complementary, not overlapping. It is precisely this complementarity that explains the additive effects seen in CagriSema.

Clinical Evidence

Phase 3: REDEFINE-1 (Obesity without Diabetes) — NEJM 2025

The most important publication to date is the REDEFINE-1 trial (published in the New England Journal of Medicine, 2025; PMID 40544433): a multicenter, randomized, double-blind Phase 3 study of roughly 3,000 adults with obesity (BMI ≥30, or ≥27 with comorbidity), but without type 2 diabetes.

• Duration: 68 weeks
• Arms: CagriSema (cagrilintide 2.4 mg + semaglutide 2.4 mg) vs. semaglutide 2.4 mg alone vs. placebo
• Weight-loss result: −22.7% (CagriSema) vs. −16.1% (semaglutide) vs. −2.1% (placebo)
• Achieving ≥20% weight loss: ~60% on CagriSema vs. ~30% on semaglutide
• HbA1c reduction: −0.9% (CagriSema) vs. −0.6% (semaglutide) — despite no diabetes diagnosis

Phase 3: REDEFINE-2 (Obesity + Type 2 Diabetes) — NEJM 2025

Published in parallel: REDEFINE-2 (PMID 40544432) — this time in patients with type 2 diabetes and obesity.

• Weight loss: −13.7% (CagriSema) vs. −9.1% (semaglutide)
• HbA1c reduction: −1.8% (CagriSema) vs. −1.4% (semaglutide)
• Share reaching HbA1c ≤6.5%: ~70% on CagriSema vs. ~50% on semaglutide

REDEFINE-1 Blood Pressure Substudy — Hypertension 2026

A sub-analysis of the REDEFINE-1 data (published in Hypertension, 2026; PMID 41328546) showed that CagriSema lowered systolic blood pressure by −7.1 mmHg (vs. −4.7 mmHg with semaglutide). That corresponds roughly to the effect of a single antihypertensive monotherapy — clinically relevant for cardiometabolic risk reduction.

Systematic Review — Am J Cardiol 2026

A systematic review and meta-analysis (PMID 41759565, Am J Cardiol 2026) compared CagriSema directly with semaglutide monotherapy and placebo across multiple studies. Result: CagriSema shows consistently superior effects on weight, HbA1c and systolic blood pressure with a comparable safety profile.

Comparison Table: Where Does Cagrilintide Stand?

Sources: STEP-1 (NEJM 2021), SURMOUNT-1 (NEJM 2022), Retatrutide NEJM 2023, REDEFINE-1 NEJM 2025, Eloralintide PMID 41109426.

Side Effects & Safety

The safety profile of CagriSema is essentially that of its individual components:

• Very common (>20%): nausea, vomiting, diarrhea, constipation — dose-dependent and mostly transient (weeks 1–8)
• Common (5–20%): headache, fatigue, injection-site reactions, decreased appetite
• Rare (<1%): pancreatitis, gallbladder disease, severe hypoglycemia (only when combined with insulin/sulfonylureas)
• Notable observation: The amylin component does not appear to increase the rate of nausea compared with GLP-1 therapy alone — an advantage over triple agonists such as retatrutide, which show somewhat higher GI side-effect rates.

Practical Implications (Provisional)

As of June 2026, CagriSema is not yet approved — neither in the US, EU, or Germany. Patients already on GLP-1 therapy (semaglutide, tirzepatide) should keep the following in mind:

• No self-medication: Amylin analogues are prescription-only substances. "Research grade" peptides from the gray market (e.g., from UPURE BIO) are not approved for self-administration and may vary widely in purity, dosage and stability.
• Titration: CagriSema uses a stepwise dose escalation over 16 weeks, similar to semaglutide, which reduces GI side effects.
• Lifestyle intervention remains mandatory: Even on CagriSema, weight loss is substantially smaller without accompanying dietary change and exercise.

Outlook: The Future of the Amylin Class

Cagrilintide is only the beginning of a broader amylin pipeline:

• Eloralintide (LY3841136) — another amylin receptor agonist from Eli Lilly, in Phase 2 (Mol Metab 2025, PMID 41109426)
• Dual amylin-calcitonin receptor agonists (DACRAs) — peptide agents that additionally address bone metabolism and energy balance (Int J Obes 2026, PMID 42265185)
• Multi-agonist architectures (amylin + GLP-1 + GIP + glucagon) — already active preclinically (Chemistry 2026, PMID 42315994)

The next 24 months will show whether amylin-based therapies truly become the third pillar of pharmacological obesity therapy — alongside incretin mimetics and (in the future) triple/quad agonists.

Conclusion

Cagrilintide and its fixed-dose combination CagriSema represent the next logical step in pharmacological obesity therapy: a complementary mechanism to the GLP-1 axis that consistently improves weight loss by 5–7 percentage points — with a comparable safety profile. For patients who do not respond adequately to GLP-1 monotherapy, CagriSema could become the preferred escalation step in the medium term.

Until approval, the therapy remains limited to clinical trials and specialized obesity centers. Those who act now benefit most from a solid lifestyle optimization — which remains the decisive amplifier of effect even under CagriSema.