Cagrilintide and semaglutide together in one weekly injection. In the phase 3 REDEFINE 1 trial, people lost 20.4% of body weight over 68 weeks against 3.0% on placebo — 22.7% among those who stayed on treatment [1]. Submitted to the US FDA in December 2025; not approved anywhere yet [9].
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team
Subcutaneous
Route
3 recommended
Sites
Once weekly
Frequency
Location
Site 01
Abdomen
Pinch the skin 2 inches from navel. Avoid the area directly around the belly button. Rotate between left and right sides.
Site 02
Outer Thigh
Middle third of the outer thigh. Keep at least 4 inches above the knee and below the hip. Alternate legs each injection.
Site 03
Upper Arm
Back or outer area of the upper arm. This site may require assistance from another person for proper technique.
Rotate between 3 sites to prevent tissue buildup and ensure consistent absorption.
Pro tip
Rotate your injection sites with each dose to prevent lipohypertrophy (buildup of fatty tissue). Keep a simple log of where you last injected.
Step by step
In trials the combination came as pre-filled pens: a dual-chamber single-dose pen delivering both drugs in one injection in phase 3 [1]; phase 2 used two separate pre-filled pens given the same day [3][7]
Inject subcutaneously in the abdomen, thigh, or upper arm, per the semaglutide component label [8]
Pro tip
This peptide uses subcutaneous injection. Inject at a 45-90 degree angle into pinched skin. Aspirate before injecting to ensure you haven't hit a blood vessel.
Timing
Optimal timing
Best time
Once weekly on a fixed dosing day — the trials scheduled a dosing day and defined catch-up rules around it [7].
With food?
The semaglutide component is injected without regard to meals [8].
Stacking notes
This IS the stack — cagrilintide and semaglutide were co-escalated together in every trial [3]. Trials prohibited combining with any other GLP-1 receptor agonist, DPP-4 inhibitor, or amylin analogue [7].
Dosing tiers
Dose
0.25 mg each
Frequency
Once weekly
Duration
Weeks 1-4 — escalation step 1
Both phase 3 REDEFINE trials initiated the fixed-dose pen at 0.25 mg of each drug [1]. Escalation step 1 in the trial protocol, held 4 weeks [7]. Human trials; 2,108 participants took the combination in REDEFINE 1 alone [1].
Dose
0.5 mg each
Frequency
Once weekly
Duration
Weeks 5-8 — escalation step 2
Escalation step 2 in the trial protocol, held 4 weeks [7]. The same participants stepped up from 0.25 mg — this is a true titration ladder, confirmed from the protocol and trial methods [1][7].
Dose
1.0 mg each
Frequency
Once weekly
Duration
Weeks 9-12 — escalation step 3
Escalation step 3 in the trial protocol, held 4 weeks [7]. Also studied as a maintenance dose in its own right: REIMAGINE 2 carried a cagrilintide-semaglutide 1.0 mg each arm of 595 people with type 2 diabetes for 68 weeks [5].
Dose
1.7 mg each
Frequency
Once weekly
Duration
Weeks 13-16 — escalation step 4
Escalation step 4 in the trial protocol, held 4 weeks before the maintenance dose [7].
Dose
2.4 mg each
Frequency
Once weekly
Duration
Week 17 on — maintenance (52 weeks in phase 3)
The maintenance dose in every phase 3 trial: 2.4 mg of each drug from week 16, held through a 52-week maintenance period in REDEFINE 1 [1]. Investigators could delay escalation or reduce the dose, and participants could stay on a submaximum dose — at week 68, 57.4% of the combination group was on the maximum dose, against 70.9% on semaglutide alone, 82.5% on cagrilintide alone and 70.6% on placebo [1]. Missed doses restarted one step lower per the protocol rules [7].
Important
When to stop
Suspicion of acute pancreatitis — the trial rule was to stop, measure amylase and lipase, and resume only if not confirmed [7]
Pregnancy [7]
A serious hypersensitivity reaction [8]
Any safety concern where your clinician judges continuing unsafe [7]
CagriSema is an investigational combination with no approved label anywhere. These stop rules are the ones its own trials used, plus the semaglutide component label — they are not medical advice. Decisions about starting, changing, or stopping belong with a qualified clinician.
Clean technique checklist
Wash hands thoroughly with soap and water before handling supplies
Swab vial tops and injection site with alcohol and let dry
Never touch the needle tip or allow it to contact non-sterile surfaces
Use a new syringe and needle for each injection
Dispose of used sharps in a proper sharps container
Store reconstituted peptides according to the storage instructions above