Reader’s guide · First edition · September 2026 · Revised September 23, 2026
Cagrilintide / Semaglutide
A guide to CagriSema: an approved drug paired with an investigational one, a decision due from the FDA this year, and a blend vial that is neither
CagriSema is Novo Nordisk's follow-up to Wegovy: the same weekly semaglutide, paired in one injection with cagrilintide, a long-acting copy of the hormone amylin that the pancreas releases with insulin to slow the stomach and signal fullness. In its main trial the pair produced about a fifth of body weight lost over sixteen months, more than either drug alone. It has been filed with the FDA, with a decision expected before the end of 2026, and it lost a head-to-head trial against tirzepatide in February. Research vendors already sell the two peptides freeze-dried together in one vial. This guide covers what each half is, what the trials showed, how the blend is dosed as sold against how the trial dosed it, and why the vial is not the drug.
Who this is for
Written for adults who are using, or being offered, a cagrilintide and semaglutide blend for weight loss, and for anyone waiting on the approved product. It summarizes the published trials and the regulatory position as of the edition date. It is not medical advice.
Two hormones, two pathways. Semaglutide mimics GLP-1, the gut hormone that raises insulin when glucose is high, slows the stomach, and cuts appetite through the brain; it is the drug in Ozempic and Wegovy and the subject of the largest evidence base in this series. Cagrilintide mimics amylin, a second hormone released alongside insulin that slows the stomach and signals fullness through a separate brain pathway. Each is built to last a week. The combination is the sponsor's answer to a simple question: if two satiety signals are better than one, how much better?
| Component | Class | Status | In this series |
|---|---|---|---|
| Semaglutide | GLP-1 receptor agonist | Approved since 2017 (diabetes) and 2021 (weight); oral tablet for weight since 2025 | The field guide |
| Cagrilintide | Long-acting amylin analog | Investigational; Phase 2 alone, Phase 3 only in combination; not approved anywhere | This title |
| CagriSema | The two co-administered weekly at 2.4 mg each | Filed with FDA December 2025; decision expected late 2026 | This title |
- The approved product, if it comes
- A weekly injection pen delivering both drugs, escalated over sixteen weeks, from the same manufacturer and supply chain as Wegovy
- The vial as sold
- Research-chemical blends of 5 mg cagrilintide with 5 mg semaglutide in one vial, also 2.5 + 2.5 and 10 + 10, reconstituted and dosed weekly by the buyer at $70 to $200 a vial
- Status
- Semaglutide is an approved drug that may no longer be compounded in ordinary circumstances. Cagrilintide has never been approved and may not be compounded at all. The blend has no pathway of any kind.
- Anti-doping
- Not prohibited by WADA; GLP-1 drugs are monitored, not banned
The trial is not the vial
Every number in this guide comes from Novo Nordisk's product, made under its controls, given by its protocol, to trial participants it selected and monitored. A research-vendor blend of the same two molecules shares the names and nothing else that the trials established.
Body weight at 68 weeks on CagriSema in adults with obesity, in the main trial's on-treatment analysis; about 20% counting everyone randomized
Semaglutide alone and cagrilintide alone in the same trial, against about 2% on placebo
In adults with type 2 diabetes, the second Phase 3 trial
CagriSema against tirzepatide head to head, February 2026; the trial did not meet its goal of showing CagriSema was at least as effective
| Trial | Who | Result | What it settles |
|---|---|---|---|
| REDEFINE 1 | About 3,400 adults with obesity, 68 weeks, four arms | The combination beat each component; most participants lost more than 5% | Two satiety signals add up, though less than the sum of the parts |
| REDEFINE 2 | Adults with obesity and type 2 diabetes | About 16% lost, in the population where every GLP-1 drug loses less | Works in diabetes, at the usual discount |
| REDEFINE 4 | Head to head against tirzepatide | Tirzepatide lost more; CagriSema failed non-inferiority | It is not the strongest weight-loss drug on the market; it is the second |
| Cagrilintide alone, Phase 2 (2021) | Adults with overweight, 26 weeks | About 11% at the top dose, more than liraglutide in the same trial | Amylin alone is a real drug, not a booster |
Side effects were the GLP-1 family's: nausea, vomiting, diarrhea, and constipation, worst at each step up, plus injection-site reactions. Long-term amylin-analog safety data are limited to this program.
What this supports
That the approved product, if approved, will be a genuine advance over Wegovy and a step behind Zepbound on weight alone. What it does not support is any figure for a vial from a chemical supplier, which has never been in a trial and whose ratio, purity, and stability no one has measured.
| Form | Instruction | What is known |
|---|---|---|
| Trial protocol | Both drugs escalated together once every 4 weeks: 0.25, 0.5, 1.0, 1.7, then 2.4 mg of each, weekly; flexible dosing allowed for tolerability | The regimen every result above comes from |
| Research blend vial | Same weekly escalation, drawn from a 5 + 5 mg vial reconstituted by the buyer | No study; the ratio is fixed at 1:1 whether or not the buyer tolerates both halves equally |
| Compounded semaglutide | A pharmacy vial of semaglutide alone, dosed as Wegovy is | Lawful only in narrow circumstances since the shortage ended in 2025; the subject of FDA warning letters through 2026 |
What the next table is, and is not
It expresses the trial escalation for the 5 + 5 mg blend vial as sold, so the arithmetic can be checked. It is not the label; there is no label. Neither cagrilintide nor the blend may lawfully be compounded, and a research-chemical vial's identity, ratio, and sterility are unverified.
- Vial
- 10 mg blend (5 mg cagrilintide, 5 mg semaglutide), as sold; identity, ratio, and quantity unverified
- Water added
- 2 mL bacteriostatic water
- Concentration
- 5 mg/mL of blend, which is 2.5 mg/mL of each peptide. One concentration for the whole course.
- Syringe
- 0.3 mL insulin syringe for the first three steps; 1 mL syringe from 1.7 mg, where the draw passes 50 units
| Weeks | Weekly dose of each | Blend per dose | Units | Used per 4 weeks |
|---|---|---|---|---|
| 1–4 | 0.25 mg | 0.5 mg | 10 | 2 mg |
| 5–8 | 0.5 mg | 1 mg | 20 | 4 mg |
| 9–12 | 1.0 mg | 2 mg | 40 | 8 mg |
| 13–16 | 1.7 mg | 3.4 mg | 68 | 13.6 mg (1.4 vials) |
| 17 on | 2.4 mg | 4.8 mg | 96 | 19.2 mg (about 2 vials) |
At full dose a 10 mg vial lasts two weeks. Missed doses in the trial were taken within five days or skipped; a blend vial has no beyond-use date once mixed and will not keep for the months a slow escalation takes.
What each draw looks like · 1 mL (100-unit) U-100 insulin syringe
The plunger tip sits on the line for the dose. Units are marks on a U-100 syringe: 100 units is 1 mL. The picture assumes the concentration in the table above; a different amount of water changes every line.
- The trial let participants slow the escalation or step back when nausea was bad. The blend cannot step back one drug without the other, which is the case for a two-pen product and against a one-vial one.
- Semaglutide in a vial from a chemical supplier is the same molecule the FDA has warned about since 2023 in compounded form: mislabeled strengths and dosing errors are the documented harm.
- A buyer already on Wegovy or Zepbound who adds a blend vial is stacking two GLP-1 doses. Nothing in the trials covers that.
The two halves are in different legal places, and the blend inherits the worse of each. Semaglutide is approved, and because an approved product is available, pharmacies may no longer make ordinary copies of it. Cagrilintide is investigational, so it is not a component of any approved drug and cannot be compounded at all. A blend of the two is an unapproved drug from any maker.
| Part | Legal position | What changed recently |
|---|---|---|
| Semaglutide (Ozempic, Wegovy) | Approved. Compounded copies were lawful during the 2022 to 2025 shortage; FDA declared it over in February 2025 and ended the grace period by May | In June 2026 FDA sent warning letters to twenty-five telehealth companies over compounded GLP-1 marketing; in May it proposed excluding semaglutide from the outsourcing-facility list |
| Cagrilintide | Investigational. Not on any compounding list and not eligible, as FDA said of retatrutide in 2025 | Phase 3 complete; no standalone application |
| CagriSema | Under FDA review since December 2025; not approved | Decision expected in the fourth quarter of 2026 |
| The blend vial | An unapproved new drug | Sold anyway under research labels |
Approval would not reach the vial
If FDA approves CagriSema, the approved product is Novo Nordisk's pen. A vendor's freeze-dried blend is not a version of it, could not be compounded from it, and would if anything become an unlawful copy of an available drug. The vial's legal position gets worse on approval day, not better.
- The approved product will carry semaglutide's boxed warning for thyroid C-cell tumors and its warnings for pancreatitis, gallbladder disease, and slowed stomach emptying under anesthesia, plus whatever the amylin half adds. A vial carries none of that on paper and all of it in the syringe.
- Insurance coverage of weight-loss drugs is the practical barrier. CagriSema will be priced and covered like Wegovy; the vial's price is the reason people buy it.
- "Research use only" with a dosing chart is the combination FDA cited in its 2026 warning letters to peptide sellers.
Reading a blend vial: milligrams, halves, and syringes9
GLP-1 doses are in milligrams and the escalation spans a tenfold range, so the same vial serves draws from 10 units to nearly a full syringe. A 1:1 blend adds one rule: each peptide's dose is half the blend figure. The mistake to avoid is applying a Wegovy dose as a blend dose, which halves the semaglutide.
units = (blend dose mg ÷ blend concentration mg/mL) × 100; each peptide gets half
A 5 + 5 mg vial (10 mg of blend) with 2 mL of water is 5 mg/mL. A dose of 1 mg of each is 2 mg of blend, 0.4 mL, or 40 units. The full 2.4 mg of each is 4.8 mg of blend, 0.96 mL, or 96 units, which needs a 1 mL syringe.
| Water added | Blend concentration | 0.25 mg each | 1 mg each | 2.4 mg each |
|---|---|---|---|---|
| 1 mL | 10 mg/mL | 5 units | 20 units | 48 units |
| 2 mL | 5 mg/mL | 10 units | 40 units | 96 units |
| 3 mL | 3.3 mg/mL | 15 units | 60 units | 144 units (two syringes) |
A 10 + 10 mg vial with 4 mL matches the 2 mL row. Reconstituted GLP-1 peptides have no tested beyond-use date outside a pharmacy; refrigerate, and assume degradation within weeks.
- Common, both halves
- Nausea, vomiting, diarrhea, constipation, and reduced appetite, worst at each escalation step; injection-site reactions. The trial's dropout for side effects was in the single digits at flexible dosing.
- Semaglutide's label
- Boxed warning for thyroid C-cell tumors seen in rodents; pancreatitis, gallbladder disease, dehydration and kidney injury from vomiting, low blood sugar with insulin or sulfonylureas, slowed stomach emptying under anesthesia, possible diabetic eye disease progression. Not for pregnancy; stop two months before trying.
- Cagrilintide
- Amylin analogs are not new: pramlintide has been approved since 2005. Cagrilintide's own long-term record is the Phase 3 program, about two years. No signal beyond the GLP-1 family's so far.
- Muscle and bone
- As with every rapid weight-loss drug, a share of the loss is lean mass. Resistance training and protein intake are the trial-supported answer.
- The vial
- Everything above, plus unverified strength and ratio, no sterility certification, and no way to step one drug back. FDA's documented harm with compounded GLP-1 vials is dosing error.
- Unknown
- Use beyond two years, use in adolescents, and what happens to the amylin half's effect when the drug is stopped. Weight regain after stopping semaglutide is well documented.
- Is this the approved product, a compounded semaglutide, or a research blend? Only the first will have a label.
- Has FDA approved CagriSema yet? If not, what am I holding, and who made it?
- Am I already on a GLP-1 drug? Then what is this adding, and who is watching the total dose?
- At my water volume, how many units is each step, and does my syringe hold the top dose?
- Do I have a history of pancreatitis, gallbladder disease, thyroid cancer, or am I pregnant or planning to be?
- What is my plan for protein and resistance training, and for the day I stop?
- If tirzepatide beat this in a head-to-head trial and is approved today, why this?
What does have evidence today
Wegovy and Zepbound, approved, with outcome trials behind semaglutide and the largest weight losses behind tirzepatide. Oral semaglutide for weight, approved in 2025, for people who will not inject. And, once approved, CagriSema from a pharmacy with a label. A blend vial is the one option on this list that none of those trials describe.
Latest
Developments since this edition, newest first. Items here are dated and sourced; they update the guide without re-editing it.
Novo holds to a fourth-quarter 2026 FDA decision for CagriSema
The half-year report keeps the obesity decision in the fourth quarter of 2026. No action date has been disclosed and no European filing timing is given.
Shareholder suit over REDEFINE 1 tolerability statements allowed to proceed
A federal judge in New Jersey let claims about Novo's description of CagriSema's tolerability and its flexible-dosing design, in which only 57 percent of participants reached the top dose, go forward while dismissing most other allegations.
In type 2 diabetes, CagriSema beats semaglutide alone on A1C and weight
In the 68-week REIMAGINE 2 trial, the 2.4 mg plus 2.4 mg dose cut HbA1c by 1.91 points and weight by 14.2 percent, against 1.75 points and 10.2 percent for semaglutide 2.4 mg. REIMAGINE 1 and 2 were published in The Lancet Diabetes and Endocrinology.
References
- 1.Lau DCW, et al. Once-weekly cagrilintide for weight management: a phase 2 dose-finding trial. Lancet. 2021;398(10317):2160-2172.
- 2.Novo Nordisk. REDEFINE 1: CagriSema in adults with overweight or obesity, 68-week results (22.7% on treatment; semaglutide 16.1%, cagrilintide 11.8%, placebo 2.3%). 2025; publication pending.
- 3.Novo Nordisk. REDEFINE 2: CagriSema in adults with obesity and type 2 diabetes, 68-week results (about 15.7%). 2025. https://clinicaltrials.gov/study/NCT04982575
- 4.Novo Nordisk. REDEFINE 4 versus tirzepatide, topline, February 23, 2026 (23.0% vs 25.5%; non-inferiority not met). https://www.sec.gov/Archives/edgar/data/353278/000117184326000996/f6k_022326.htm
- 5.PharmExec. Novo Nordisk submits NDA to FDA for CagriSema. December 2025; and company guidance on a fourth-quarter 2026 decision. https://www.pharmexec.com/view/novo-nordisk-submits-nda-fda-cagrisema
- 6.Wegovy (semaglutide) prescribing information. Novo Nordisk, current revision.
- 7.U.S. Food and Drug Administration. Semaglutide shortage resolved, February 2025; warning letters to telehealth companies over compounded GLP-1 marketing, 2026. https://www.fda.gov/news-events/press-announcements/fda-warns-30-telehealth-companies-against-illegal-marketing-compounded-glp-1s
- 8.U.S. Food and Drug Administration. Proposed 503B bulks list excluding semaglutide, tirzepatide, and liraglutide. Federal Register, May 1, 2026. https://www.federalregister.gov/documents/2026/05/01/2026-08552/list-of-bulk-drug-substances-for-which-there-is-a-clinical-need-under-section-503b-of-the-federal
- 9.Representative cagrilintide / semaglutide blend listings (2.5 + 2.5, 5 + 5, 10 + 10 mg) and dosing instructions, research-chemical vendors, September 2026. https://valarpeptides.com/product/cagrilintide-semaglutide-blend-5mg-5mg/