Semaglutide with cagrilintide
Grey-market semaglutide with cagrilintide blend
Written by Aaron CuhaReviewed Sep 2026
Also known as: Grey-market CagriSema, Sema cagri blend
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
This is the one blend on this site where somebody actually ran the combination trial, and it worked. The drug company version reached 20.4 percent weight loss. What research sellers put in a vial under the same description is not that product.
What people take it for
- Losing more weight than semaglutide alone gives.
- Turning down hunger from two directions.
- Breaking a plateau.
What the trials actually showed
The real trial is called REDEFINE 1. It put 3,417 people into four groups. The combination group lost 20.4 percent of their body weight at week 68. The dummy shot group lost 3.0 percent. That is a gap of 17.3 percentage points. Before that, a smaller trial stepped the two up together over 16 weeks in 96 people. It showed the amylin drug did not change how much semaglutide got into the blood. For comparison, semaglutide alone gave 14.9 percent at 68 weeks in STEP 1, and the amylin drug alone gave 6.0 to 10.8 percent at 26 weeks. Now the cost, which the marketing leaves out. Stomach side effects hit 79.6 percent of the combination group, against 39.9 percent on the dummy shot. Nearly four in five people. Mostly short lived and mild to moderate, but four in five.
What people report
Reports, not trial results
The good
- Hunger stays quiet, steadier than on semaglutide alone.
- Weight comes off.
The bad
- Nausea and vomiting, worst at dose steps. This matches the trial.
- Constipation.
- Fast early loss then a plateau.
- Seller vials do not match the step up schedule used in the trial, and people guess at it.
Where these come from: The 79.6 percent figure comes straight from the trial side effect table. The rest comes from patient forums and is people talking, using unverified material.
My bottom line
This is the rare case where the combination really was tested, and it is a high bar every other blend on this site should be judged against. It also means buying an untested copy makes less sense, not more.
An opinion, not a finding. I am a coach, not a doctor.
Overview
The rare blend whose combination has actually been trialled, at scale: co-administered cagrilintide and semaglutide produced 20.4% mean weight loss at week 68 against 3.0% on placebo in 3,417 participants. What research vendors sell under this description is not that product, at that ratio, from that supply chain, and gastrointestinal adverse events affected 79.6% of the combination group in the trial.
This page has to do two jobs at once, and keeping them separate is the whole point.
First job: the combination is real and it works. REDEFINE 1 randomised 3,417 participants to cagrilintide-semaglutide, semaglutide alone, cagrilintide alone or placebo. Estimated mean body weight change from baseline to week 68 was 20.4% on the combination against 3.0% on placebo, a difference of 17.3 percentage points, and participants on the combination were more likely to reach 5%, 20%, 25% and 30% weight loss targets. Before that, a phase 1b trial co-escalated the two over 16 weeks in 96 people and found cagrilintide exposure was dose-proportional and did not affect semaglutide exposure. So the pharmacology of combining an amylin analogue with this particular GLP-1 has been examined properly, which is not something any other page in this batch can say.
Second job: none of that describes a vial from a peptide vendor. The trial used a co-formulated product made to pharmaceutical specification, with doses escalated on a defined schedule under supervision, and a defined ratio at each step. A grey-market blend uses whatever ratio the vendor chose, fixed, from material nobody has assayed, escalated by the buyer. The evidence belongs to the first thing.
The cost of the combination in the trial is also part of the result and gets left out of the marketing. Gastrointestinal adverse events affected 79.6% of the combination group against 39.9% on placebo: nausea, vomiting, diarrhoea, constipation or abdominal pain. Mainly transient and mild to moderate, but affecting nearly four in five people.
One more thing. Because semaglutide is an approved medicine, a person who wants this can raise it with a prescriber; because the branded co-formulation exists, this is one of the few blends in the database where the researched version is a real option rather than a hypothetical one.
Mechanism of action
Semaglutide agonises the GLP-1 receptor. Cagrilintide is a long-acting amylin analogue acting on satiety through amylin receptor signalling in the hindbrain. The two satiety pathways are separate, which is the mechanistic case for combining them, and unlike most entries in this batch that case has been tested: the phase 1b work showed dose-proportional cagrilintide exposure with no effect on semaglutide exposure, and the phase 3 trial showed the combination outperformed either component.
Human evidence
This is the one combination in the batch with its own phase 3 trial. What is sold by vendors is a copy of it with none of the controls.
- The combination: 20.4% mean weight loss at 68 weeks against 3.0% on placebo in 3,417 participants.
- Pharmacokinetic interaction: cagrilintide exposure was dose-proportional and did not affect semaglutide exposure across 16 weeks of co-escalation in 96 people.
- Semaglutide alone: 14.9% at 68 weeks in STEP 1.
- Cagrilintide alone: 6.0% to 10.8% at 26 weeks.
- Cost of the combination: gastrointestinal adverse events in 79.6% of the combination group against 39.9% on placebo.
What this does not tell you: The trial result belongs to a co-formulated pharmaceutical product with defined ratios, defined escalation and supervision. A fixed-ratio vendor blend of unassayed material shares the concept and none of those conditions, and the vendor ratio is chosen rather than derived from the trial.
What it has been measured to do
Measured in people
Goals Semaglutide with cagrilintide has been measured for in a human being, most people first. Counts come from the study lines on this page and deliberately undercount.
- Losing weight3,417 people · 2 studies
What people using it report
Uncontrolled and self-selected, so it cannot show that anything works. It is still the best guide on this page to what people actually do with Semaglutide with cagrilintide, what they expect, and what goes wrong. The full account, including the negative reports, is below.
33 of the 36 indexed goals have no study of any kind behind Semaglutide with cagrilintide
No trial, no animal work, no cell work on this page reports a result for these. That is an absence of evidence rather than evidence of absence, but it does mean anything you have been told about Semaglutide with cagrilintide and one of these did not come from a study cited here.
Reading the research record
The interesting thing about this product is what it reveals about the rest of the category. Ninety percent of the blends sold in this market justify themselves with a mechanistic story and no combination trial. Here a combination trial exists, it is large, and it is positive, which means the honest version of the argument for blends can be made. It also means the standard has been set: this is what testing a combination looks like, and every other blend in this database should be read against it.
The second observation is that having a trialled version available makes the grey-market version harder to justify rather than easier. When the researched product exists as a prescribable option, buying an unassayed fixed-ratio copy is a choice to take the concept without the controls, and the escalation schedule in the trial is a large part of why nearly four in five people tolerated the gastrointestinal load well enough to finish.
The evidence, charted
Fig. 1a · evidence scale
4,219people, across 3 human studies cited here
- 2025 · New England Journal of Medicine3,41781%
- 2021 · The Lancet70617%
- 2021 · The Lancet962%
One study holds 81% of these participants, so the total is less independent than its size suggests. Counts are the enrollment each human citation on this page states, which includes observational cohorts where nobody was given the compound. 1 further human citation states no participant count and is not counted here. Studies still recruiting are excluded, and only studies cited on this page are counted.
Fig. 1b · evidence mix
All 4 citations here are human work.
- Human · given to people4100%
Counted from the citation list on this page, typed as this page types it. It understates any literature larger than the sources we cite, and a review counts once however many studies it covers.
Fig. 2 · evidence over time
Citations here span just two years, 2021 and 2025.
Too few distinct publication years on this page to plot as a timeline.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four jurisdictions shown. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Fig. 5 · molecular identity
- Modality
- Blend
- Molecular weight
- Not on file
- Half-life
- Stated in words, not a number
- Sequence length
- None on file
see the exact wording below
Half-life as stated on file: Not defined for a grey-market mixture. Both components support once-weekly dosing individually and the trialled co-formulation is given weekly.
No amino acid sequence is on file for Semaglutide with cagrilintide, which is expected: a blend is not built from residues.
Fig. 6 · what is in the vial
No mass split can be drawn for this blend
Sellers do not publish a consistent vial size for Semaglutide with cagrilintide, so the share of each component is not knowable from the outside. Splitting the bar evenly would invent the number this page exists to question.
- Semaglutideamount not stated
- Cagrilintideamount not stated
Component list from the product labels we hold. Amounts are label mass, never a dose.
Key studies & citations
- Human2025
Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity
REDEFINE 1. 3,417 participants randomised to cagrilintide-semaglutide, semaglutide alone, cagrilintide alone or placebo. Estimated mean body weight change to week 68 was 20.4% on the combination against 3.0% on placebo, a difference of 17.3 percentage points. Gastrointestinal adverse events affected 79.6% of the combination group against 39.9% on placebo, mainly transient and mild to moderate. This is the combination itself, tested as a combination.
New England Journal of Medicine - Human2021
Safety, tolerability, pharmacokinetics, and pharmacodynamics of concomitant administration of multiple doses of cagrilintide with semaglutide 2·4 mg for weight management: a randomised, controlled, phase 1b trial
96 people, six sequential cohorts, weekly cagrilintide 0.16 to 4.5 mg or placebo with weekly semaglutide 2.4 mg, co-escalated in four-week intervals over 16 weeks. Of 566 adverse events reported in 92 participants, 207 were gastrointestinal. Cagrilintide exposure was dose-proportional and did not affect semaglutide exposure. This is the pharmacokinetic interaction study the grey-market blend borrows without matching.
The Lancet - Human2021
Once-Weekly Semaglutide in Adults with Overweight or Obesity
STEP 1. Semaglutide 2.4 mg weekly gave a 14.9% mean weight change at 68 weeks against 2.4% on placebo. This is the single-agent comparator that the combination is measured against.
New England Journal of Medicine - Human2021
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
706 adults across cagrilintide doses of 0.3 to 4.5 mg. Mean weight reductions at 26 weeks of 6.0% to 10.8% against 3.0% on placebo. The amylin half on its own.
The Lancet
What users report
Self-reported experiences, not evidence. Nothing below was measured under controlled conditions, and reports like these cannot separate a real effect from placebo, from the training or diet change that accompanied it, or from what the product actually contained. They are here because knowing what people describe, including what goes wrong, is worth reading alongside the studies.
- Appetite suppression described as stronger and steadier than semaglutide alone.
- Nausea and vomiting, frequently at escalation steps, matching the pattern in the trial.
- Constipation.
- Fast early weight loss followed by a plateau.
- Disagreement about ratio, because vendor blends do not match the escalation schedule used in the trial and buyers escalate by their own judgement.
Sources: The gastrointestinal figures come from the REDEFINE 1 adverse event table. The rest comes from forums including r/Semaglutide and r/peptides, and is uncontrolled self-report from people using unverified material.
Frequently asked questions
Has this combination actually been tested?
Yes, which makes it unusual here. REDEFINE 1 randomised 3,417 participants and found 20.4% mean weight loss at week 68 on the combination against 3.0% on placebo.
So is the vendor blend the same thing?
No. The trial used a co-formulated pharmaceutical product at defined ratios with a defined escalation schedule under supervision. A vendor blend is a fixed ratio chosen by the seller, from unassayed material, escalated by the buyer.
How bad were the side effects in the trial?
Gastrointestinal adverse events affected 79.6% of the combination group against 39.9% on placebo. Mainly transient and mild to moderate, but nearly four in five people.
How much better is it than semaglutide alone?
In the trial, 20.4% at week 68 for the combination. STEP 1 gave 14.9% at week 68 for semaglutide 2.4 mg alone. Different trials, so that is a comparison to hold loosely, though REDEFINE 1 also contained its own semaglutide arm.
Does cagrilintide change how semaglutide behaves in the body?
The phase 1b trial found cagrilintide exposure was dose-proportional and did not affect semaglutide exposure over 16 weeks of co-escalation.