Cagrilintide

Think of it like a promising new car that has aced its crash tests and proving-ground laps. The trial data are real and impressive. But it hasn't yet passed its MOT or been registered for the road. No regulator has stamped it road-legal, and the version sold online isn't the factory model.

A long-acting synthetic analogue of the satiety hormone amylin. It activates amylin/calcitonin (AMY) receptors in the area postrema and hypothalamus, suppressing appetite, slowing gastric emptying and reducing glucagon. This appetite-regulation pathway is distinct from and complementary to GLP-1 receptor agonists, which is why it is combined with semaglutide in CagriSema. Given by once-weekly subcutaneous injection.

Research contexts. Not proven uses, and not recommendations.

Unusually strong for a drug not yet on the market, though incomplete. Published randomised controlled trials include a Phase 1b combination study (Lancet 2021), a Phase 2 dose-finding monotherapy trial (Lancet 2021) showing roughly 10.8% weight loss at 26 weeks, outperforming liraglutide, and a Phase 2 combination trial in type 2 diabetes (Lancet 2023). The 68-week Phase 3 REDEFINE 1 trial reported approximately 11.8% mean body-weight reduction with cagrilintide monotherapy versus about 2.3% with placebo. That monotherapy headline was first reported through conference and company disclosure rather than a peer-reviewed primary paper. A dedicated Phase 3 monotherapy programme is underway. Most data sit within Novo Nordisk's CagriSema/REDEFINE programme, with limited independent replication.

• !Not licensed by the MHRA or any other regulator. It is investigational, so its safety/efficacy balance has not been signed off for routine clinical use.
• !Gastrointestinal side effects (nausea, vomiting, diarrhoea, constipation) are common.
• !Long-term safety data are still being collected; the dedicated monotherapy Phase 3 programme had not fully reported in a peer-reviewed primary publication at the time of writing.
• !Grey-market 'cagrilintide' or 'cagri' powders sold online are unlicensed research chemicals of unverified identity, purity and sterility. Buyers cannot confirm what they are injecting.
• !Most published efficacy data come from the manufacturer's trial programme, with limited independent replication.
• !The strongest weight-loss results come from combination with semaglutide (CagriSema). Cagrilintide's standalone effect is more modest.

Investigational drug, not a licensed UK medicine. The MHRA has not granted cagrilintide a marketing authorisation, it is not available on prescription or via the NHS, and the CagriSema combination is at most under regulatory review. Legitimate UK access is only through enrolment in a registered clinical trial. Material sold online as 'cagrilintide' or 'cagri' is an unlicensed research chemical marketed 'not for human consumption'. Supplying it for human use breaches the Human Medicines Regulations 2012.

• · Phase 3· Completed / reported

  REDEFINE 1: 68-week Phase 3 trial of once-weekly CagriSema, cagrilintide monotherapy and semaglutide monotherapy vs placebo in adults with obesity/overweight without type 2 diabetes

  Cagrilintide monotherapy arm: ~11.8% mean weight loss vs ~2.3% placebo at 68 weeks. Headline monotherapy figure reported via company/conference disclosure.

• · Phase 3· Ongoing

  Dedicated Phase 3 monotherapy programme evaluating cagrilintide on its own for weight management

  Standalone monotherapy programme triggered by REDEFINE 1 data.

1. 01
   Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial — Lau DCW, et al., The Lancet (2021)

   Phase 2 monotherapy dose-finding trial; ~10.8% weight loss at 26 weeks at the top dose, outperforming liraglutide.

2. 02
   Safety, tolerability, pharmacokinetics, and pharmacodynamics of concomitant administration of multiple doses of cagrilintide with semaglutide for weight management: a randomised, controlled, phase 1b trial — Enebo LB, et al., The Lancet (2021)

   Phase 1b combination (CagriSema) study establishing PK/PD and tolerability. PMID not confirmed here; PubMed search link provided.

3. 03
   Efficacy and safety of co-administered once-weekly cagrilintide with once-weekly semaglutide in type 2 diabetes: a multicentre, randomised, double-blind, active-controlled, phase 2 trial — Frias JP, et al., The Lancet (2023)

   Phase 2 combination trial in type 2 diabetes.

4. 04
   Novo Nordisk presents phase 3 data for next-generation amylin cagrilintide, leading to advancement into a dedicated clinical programme (REDEFINE 1; ~11.8% mean weight loss at 68 weeks with monotherapy) — Novo Nordisk, Novo Nordisk company announcement / press release (2025)

   Phase 3 monotherapy results; company disclosure, not a peer-reviewed primary publication at time of writing. Verify against the eventual primary paper.