Cagrilintide / Retatrutide
Blend of cagrilintide (amylin analog) and retatrutide (triple GLP-1/GIP/glucagon agonist), studied for weight management.
This is a combination sold as one vial. It has not been studied as a single substance, so what is known is what is known about each part, linked above. Sources that report a dose for the blend report it for that mixture, not for any component on its own.
We have not published an audit on Cagrilintide / Retatrutide. Everything below is reference material, not our own reading of the literature, treat it as a starting point for questions, not as a grade.
How it is thought to work
Combines amylin-receptor agonism with triple incretin agonism; studied for appetite regulation and weight management.
Retatrutide hits three receptors at once (GLP-1, GIP, glucagon) to reduce appetite, improve insulin signaling, and increase fat burning, while cagrilintide adds a separate amylin-based fullness signal in the hindbrain that retatrutide does not cover on its own.
Reported side effects
The most common concerns are GI side effects (nausea, vomiting, constipation) from both compounds slowing gastric emptying, plus retatrutide-related tingling or numbness (dysesthesia) during dose escalation.
Who should avoid it
People with diabetes, kidney disease, gallbladder or pancreatitis history, liver disease, or cardiovascular concerns should discuss baseline labs with a clinician before starting, and the stack should not be combined with semaglutide or tirzepatide.
What gets monitored
A1c (baseline); Fasting glucose (follow-up); Comprehensive metabolic panel / CMP, kidney function, liver enzymes, electrolytes, glucose (baseline); Lipid panel (follow-up); Blood pressure and resting heart rate (follow-up). Repeat metabolic markers after 4-12 weeks, with closer review during dose escalation or major appetite changes. For longer protocols, review metabolic, kidney, liver, and cardiovascular trends every 3-6 months with a clinician. [Source: peptidedosingprotocols.com]
What sources report
These are figures published elsewhere, reproduced with their source. Peppersite does not recommend an amount for Cagrilintide / Retatrutide or for anything else, and nothing below has been checked against the study it came from.
| Amount | Frequency | Route | Reported by |
|---|---|---|---|
| Retatrutide 12 mg/week + Cagrilintide 2.4 mg/week (maintenance); pre-blend most common as 12.5 mg retatrutide + 2.5 mg cagrilintide per vial | Once weekly24-week ramp + open-ended maintenance; community: 16-24 weeks on, 4-8 weeks off | Subcutaneous | peptidedosingprotocols.comWhat it saysHide(secondary reference; provider confirmation required). [Source: peptidedosingprotocols.com] |
- Once weekly24-week ramp + open-ended maintenance; community: 16-24 weeks on, 4-8 weeks off
- Subcutaneous
- peptidedosingprotocols.com
What it saysHide
(secondary reference; provider confirmation required). [Source: peptidedosingprotocols.com]
- Pre-blend (15 mg vial: 12.5 mg retatrutide + 2.5 mg cagrilintide): add 2.5 mL bacteriostatic water (BAC water) slowly down the vial wall; resulting concentration is 5.0 mg/mL retatrutide + 1.0 mg/mL cagrilintide (6.0 mg/mL total blend). Both compounds use U-100 insulin syringes. BAC water is added slowly down the vial wall. Separate vials each use 1-2 mL BAC water per vial. Reconstituted vials are stable for 28-30 days at 2-8 °C.
Common questions
What is the cagrilintide + retatrutide stack?
It is a two-compound research protocol that pairs cagrilintide (an amylin analog that signals fullness through the hindbrain) with retatrutide (a triple GLP-1 / GIP / glucagon agonist). Together they cover four receptor pathways. No clinical trial has tested the exact combination, but the closely related CagriSema (cagrilintide + semaglutide) Phase 3 trial showed that adding amylin to a GLP-1 backbone improves weight loss.
What is 'cag peptide' or 'reta/cag'?
Cag is short for cagrilintide. Reta/cag (or reta-cag) is shorthand for this two-compound stack. Supplier blend names like ma-3rt/cag, fg3-r/cag, GLP-3/cag, 3R + cagri, and AO-3RT/cag all refer to a retatrutide + cagrilintide pre-blend. The mg breakdown on the actual vial label is what matters — the brand name is just supplier shorthand.
How much cagrilintide do you take with retatrutide?
Most community protocols start cagrilintide at 0.25 mg/week once retatrutide is established, then step up every 4 weeks to 0.5, 1.0, 1.7, and 2.4 mg/week. Retatrutide titrates separately from 2 mg up to 12 mg/week.
What is in a 12.5 mg / 2.5 mg reta/cag blend vial?
A standard 5:1 pre-blend contains 12.5 mg retatrutide + 2.5 mg cagrilintide = 15 mg total in one vial. Reconstituted with 2.5 mL bacteriostatic water, this gives 5.0 mg/mL retatrutide + 1.0 mg/mL cagrilintide. A 0.40 mL draw delivers 2.0 mg reta + 0.4 mg cag.
Open the reconstitution calculator →How do you reconstitute the 12.5 mg / 2.5 mg reta-cag blend?
Add 2.5 mL of bacteriostatic water to the 15 mg total pre-blend vial. Inject the BAC water slowly down the inside of the glass — never aim it at the powder. Swirl gently for 30–60 seconds. Do not shake. The resulting concentration is 5.0 mg/mL retatrutide + 1.0 mg/mL cagrilintide. Use within 28–30 days when stored at 2–8 °C.
Open the reconstitution calculator →Should I use a pre-blended vial or separate vials?
Pre-blend is simpler — one injection, one reconstitution, one math step. The trade-off is the fixed 5:1 ratio: you cannot raise one compound without raising the other. Separate vials are better for staggered titration (start retatrutide alone first, then add cagrilintide at Week 9) and for users who have GI sensitivity. For most first-time stack users, separate vials are the safer pick.
Open the reconstitution calculator →Can you take cagrilintide and retatrutide together?
Yes — both compounds are dosed once weekly and the schedules line up well. Same day at different injection sites is standard. The catch is that both slow digestion, so GI side effects can stack. Run retatrutide alone for the first 8 weeks, then add cagrilintide at the lowest dose (0.25 mg). Step both compounds up slowly.
What is the starting dose for cagrilintide when stacking with retatrutide?
0.25 mg/week is the standard starting dose for cagrilintide in a staggered protocol. Hold for at least 2 weeks before stepping up. The titration ladder is 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg/week, with each step usually held 2–4 weeks. Drop back a step if GI side effects are intense.
Sources
The reference sections above are imported from our compound knowledge base, which classes the evidence for Cagrilintide / Retatrutide as emerging. That classification is the knowledge base’s, not ours, our own grade appears only where an audit is linked above. Research use only; nothing here is medical advice or a protocol.
Blend of cagrilintide (amylin analog) and tirzepatide (GIP/GLP-1 dual agonist), studied for weight management.
Investigational fixed-dose combination of cagrilintide (a long-acting amylin analog) and semaglutide (a GLP-1 receptor agonist), studied once weekly for weight management.
Investigational GLP-1 and glucagon receptor dual agonist studied for weight management and metabolic health.
Investigational triple GLP-1 / GIP / glucagon receptor agonist studied for weight management.
Semaglutide is one of the most widely studied weight-loss and diabetes drugs in the world.
Dual GIP and GLP-1 receptor agonist studied for weight management and glycemic control.