Cagrilintide + Retatrutide
Triple agonist plus an amylin analog
Experimental material. Read before using anything from here.
Nothing on this page is a medical recommendation, prescription or treatment plan. It is an organized translation of protocols circulating in research communities and, where it exists, of what published trials tested. The two are marked differently — and they are not equivalent.
Most of the compounds here have no FDA approval for human use. Several are sold labeled "research use only", which means they have not gone through purity, sterility or dosage controls for human consumption. A community-reported dose is not a validated dose: it is what someone reported having done.
Talk to a licensed health professional before considering any of these compounds. If you already use one and feel anything unexpected, seek care — do not wait for the next routine test.
No package insert, no approved dose
This compound has no FDA registration — checked in the label database on September 4, 2026. That does not make it safer than semaglutide or tirzepatide, which carry a black box warning: it makes it less known. There is no approved titration ladder, no defined maximum dose and no official contraindication list to compare with the tables on this page.
The related analogs that already have a package insert carry a thyroid C-cell tumor warning — and tirzepatide is contraindicated in medullary thyroid carcinoma and MEN 2 in the package inserts of both countries, while semaglutide is only in the United States. The full audit is in The GLP-1s against the package insert.
Summary
Combines two investigational weight-loss peptides. Retatrutide is Eli Lilly's triple agonist — a weekly injection that hits three receptors at the same time (GLP-1, GIP, glucagon). Cagrilintide is a long-acting amylin analog. Order matters: retatrutide is stabilized before cagrilintide is added.
Quick reference
- Formats
- Pre-mixed vials (most common: 12.5 mg of retatrutide + 2.5 mg of cagrilintide) or two separate vials.
- Schedule
- 1×/week for both. Same day, different injection sites.
- Titration
- Start with retatrutide alone for 4–8 weeks, then add cagrilintide. Escalate together, slowly.
- Status
- Both investigational. CagriSema, the closest analog, has phase 3 data.
Pre-Blend Weekly Schedule Example
| Phase | Weeks | Draw volume | Reta Delivered | Cag Delivered |
|---|---|---|---|---|
| Start | 1-4 | 0.40 mL (40 units) | 2.0 mg | 0.4 mg |
| Step 1 | 5-8 | 0.60 mL (60 units) | 3.0 mg | 0.6 mg |
| Step 2 | 9-16 | 0.80 mL (80 units) | 4.0 mg | 0.8 mg |
| Step 3 | 17-20 | 1.20 mL (120 units) | 6.0 mg | 1.2 mg |
| Step 4 | 21-24 | 1.60 mL (160 units) | 8.0 mg | 1.6 mg |
| Maintenance | 25+ | 2.40 mL (240 units) | 12.0 mg | 2.4 mg |
Full Staggered Titration Schedule
| Phase | Weeks | Retatrutide | Cagrilintide | Notes |
|---|---|---|---|---|
| Reta initiation | 1-4 | 2 mg/week | Not started | Confirm retatrutide GI tolerance first. |
| Reta escalation 1 | 5-8 | 4 mg/week | Not started | Continue retatrutide alone. |
| Cag introduction | 9-12 | 4 mg/week (hold) | 0.25 mg/week | Add cagrilintide at the lowest dose. Hold reta steady. |
| Dual escalation 1 | 13-16 | 8 mg/week | 0.5 mg/week | GI effects often peak here. |
| Dual escalation 2 | 17-20 | 8 mg/week (hold) | 1.0 mg/week | Hold reta, raise cag. |
| Dual escalation 3 | 21-24 | 12 mg/week | 1.7 mg/week | Approach maintenance. |
| Maintenance | 25+ | 12 mg/week | 2.4 mg/week | Full four-receptor coverage if tolerated. |
Cycle Guidelines
| Approach | Duration | Off period | Best for |
|---|---|---|---|
| Full staggered titration | 24-week ramp + open-ended maintenance | Community: 16-24 weeks on, 4-8 weeks off | Primary weight-loss strategy with full pathway coverage |
| Reta-first, cag add-on | Stabilize reta at 8-12 mg, then add cag for 12+ weeks | Cag can be cycled on its own | Users already on retatrutide who want more satiety |
| Short-cycle test | 8-12 weeks at sub-maximal doses | 4 weeks off | Initial tolerability check |
Choose Your Reconstitution Format
| Metric | Value |
|---|---|
| Blend composition | 12.5 mg retatrutide + 2.5 mg cagrilintide |
| BAC water added | 2.5 mL |
| Concentration | 5.0 mg/mL retatrutide + 1.0 mg/mL cagrilintide |
| Ratio held constant | 5:1 (reta : cag) |
Choose Your Reconstitution Format
| Draw volume | Units | Retatrutide | Cagrilintide |
|---|---|---|---|
| 0.20 mL | 20 units | 1.0 mg | 0.2 mg |
| 0.40 mL | 40 units | 2.0 mg | 0.4 mg |
| 0.60 mL | 60 units | 3.0 mg | 0.6 mg |
| 0.80 mL | 80 units | 4.0 mg | 0.8 mg |
| 1.20 mL | 120 units* | 6.0 mg | 1.2 mg |
| 1.60 mL | 160 units* | 8.0 mg | 1.6 mg |
| 2.40 mL | 240 units* | 12.0 mg | 2.4 mg |
Retatrutide Reconstitution
| Vial size | BAC water added | Concentration | 2 mg Dose | 4 mg dose | 8 mg dose | 12 mg dose |
|---|---|---|---|---|---|---|
| 5 mg | 1.0 mL | 5 mg/mL | 0.40 mL (40 units) | 0.80 mL (80 units) | N/A | N/A |
| 10 mg | 1.0 mL | 10 mg/mL | 0.20 mL (20 units) | 0.40 mL (40 units) | 0.80 mL (80 units) | 1.20 mL (120 units*) |
| 10 mg | 2.0 mL | 5 mg/mL | 0.40 mL (40 units) | 0.80 mL (80 units) | 1.60 mL (160 units*) | 2.40 mL (240 units*) |
| 20 mg | 2.0 mL | 10 mg/mL | 0.20 mL (20 units) | 0.40 mL (40 units) | 0.80 mL (80 units) | 1.20 mL (120 units*) |
Cagrilintide Reconstitution
| Vial size | BAC water added | Concentration | 0.25 mg | 0.5 mg | 1.0 mg | 2.4 mg |
|---|---|---|---|---|---|---|
| 5 mg | 2.0 mL | 2.5 mg/mL | 0.10 mL (10 units) | 0.20 mL (20 units) | 0.40 mL (40 units) | 0.96 mL (96 units) |
| 10 mg | 2.0 mL | 5.0 mg/mL | 0.05 mL (5 units) | 0.10 mL (10 units) | 0.20 mL (20 units) | 0.48 mL (48 units) |
| 10 mg | 1.0 mL | 10.0 mg/mL | 0.025 mL (2.5 units) | 0.05 mL (5 units) | 0.10 mL (10 units) | 0.24 mL (24 units) |
Cagrilintide + Retatrutide vs CagriSema vs Retatrutide Alone
| Feature | Cagrilintide + Retatrutide | CagriSema (cagrilintide + semaglutide) | Retatrutide Solo |
|---|---|---|---|
| Components | Cagrilintide + Retatrutide | Cagrilintide + Semaglutide | Retatrutide only |
| Receptor coverage | AMY + GLP-1R + GIPR + GCGR | AMY + GLP-1R | GLP-1R + GIPR + GCGR |
| Combination clinical data | None (speculative) | Phase 3 REDEFINE-1: ~22.7% at 68 weeks | Not a combination; Phase 3 monotherapy available |
| Expected GI burden | Very high | High | High |
| Dysesthesia risk | Yes (retatrutide component) | No | Yes |
| Injections per week | 2 (separate) or 1 (pre-blend) | 1 or 2 | 1 |
| Regulatory status | Neither approved; no combo data | NDA under FDA review | Phase 3 ongoing |
| Estimated grey-market cost | $600-$1,200/month | $500-$900/month | $300-$600/month |
Storage and handling
The rules below apply to practically every lyophilized peptide in this reference. Where a compound has its own requirement, it appears in the table in the previous section.
- Lyophilized powder, sealed: refrigerator, between 2 and 8 °C, protected from light. Many tolerate room temperature for short transport periods, but that is tolerance, not a recommendation.
- After reconstitution: always refrigerated, between 2 and 8 °C. The stability window drops to days or a few weeks, depending on the compound.
- Never freeze after reconstituting. The freeze–thaw cycle degrades the peptide.
- Do not shake. Swirl the vial slowly. Shaking breaks the peptide chain.
- Bacteriostatic water down the wall of the vial, in a slow stream, not squirted directly onto the powder.
- Cloudy solution, with particles or a color change: discard. There is no recovery.
Lab tests and monitoring
This list is the one that appears recurrently in the source, with small variations by compound. It serves as a starting point for a conversation with a professional — not as a substitute for that conversation.
- Before starting: complete blood count, comprehensive metabolic panel, lipid panel, fasting glucose and HbA1c, TSH and free T4, blood pressure and resting heart rate.
- Depending on the compound: IGF-1 (GH axis), lipase and amylase (VIP and the incretin agonists), serum copper and ceruloplasmin (GHK-Cu and blends containing it), CRP.
- Reassessment: most protocols review between week 4 and week 8, and then every 8–12 weeks.
- Do not wait for the routine lab test in the face of abdominal pain, visual changes, a change in a mole, shortness of breath, asymmetric swelling or any new and persistent symptom. That is a reason to seek care, not a spreadsheet item.
Evidence limits
Data source: peptidedosingprotocols.com, accessed on September 3, 2026. Translation and organization in Portuguese are original work. No primary source (PubMed, trial registry, package insert) was checked in building this page — the check was against the secondary source, and that alone.