Novo's weekly amylin analogue, the 'cagri' in CagriSema; a hard appetite brake, often with heavy fatigue.
Safety tier
Avoid
strict bar
Positive
36%
of 25 reports
Per month
≈ €27–110
estimate
Rank
#60
of 61 research peptides
At a glance
Access
Grey market
InjectionFelt in 24 h – 2 days, lasts 4–6 days
15 min1 h6 h1 day1 week
Strict case
Unapproved drug bought as grey-market vials and usually stacked on retatrutide or tirzepatide outside any trial: gallbladder disease and fast lean-mass loss, severe hypoglycaemia if combined with insulin (amylin class), days of not eating from dosing errors with home-reconstituted vials, and a pH-sensitive peptide sold in plain powder.
Best effects
Strong appetite and food-noise suppression, often described as aversion to food · breaks weight-loss stalls on GLP-1 drugs · 6-11% weight loss alone in trials (26-68 weeks) · no heart-rate rise (heart rate fell 3.3 bpm in REDEFINE 1)
Downsides
Fatigue or lethargy, the commonest user complaint · low mood or anhedonia · unable to eat for days, nausea and vomiting when started above 0.25 mg · constipation and bloating · injection-site reactions (17% vs 3% on placebo in REDEFINE 1) · tolerance within weeks for some
Typical use
Trials: 0.3-4.5 mg once weekly, 2.4 mg as the CagriSema dose after slow escalation. Grey-market users: start 0.1-0.25 mg, usually 0.25-2 mg weekly alongside a GLP-1. Users report 54–210 mcg/day (median 140 mcg, n=9).
Stacked with
Stacked with
Retatrutide: The commonest pairing, added at 0.1-1 mg when retatrutide leaves hunger late in the week; most fatigue and can't-eat reports come from this stack. · tirzepatide or semaglutide: A home-made CagriSema; semaglutide plus cagrilintide is the pairing Novo actually tested. · mazdutide or survodutide: Occasionally combined to hit amylin, GLP-1 and glucagon receptors at once; never studied.
Safety
Watch
Gallbladder disorders: 2.3% vs 1.0% on placebo with cagrilintide alone, 4.1% with CagriSema (REDEFINE 1) · Pancreatitis seen with CagriSema (0.2%), none with cagrilintide alone in REDEFINE 1 · Severe hypoglycaemia with insulin or sulfonylureas: the amylin analogue pramlintide carries a boxed warning for this · Rapid loss including lean mass when stacked on GLP-1 drugs and eating drops to near zero · Calcitonin-receptor agonism: long-term calcitonin was restricted by the EMA in 2012 over a cancer signal (theoretical for cagrilintide) · Grey-market product: Novo formulates it at about pH 4 because amylin analogues aggregate; vendor powder and GLP-1 blends are mixed in plain bacteriostatic water
Tier by safety barStrict AvoidBalanced CautionEvidence only Caution
Seen harm1 of 3
Mechanism2 of 3
Data gap1 of 3
Silent harm3 of 3
Product3 of 3
Never if
Pregnancy, planned pregnancy or breastfeeding · Insulin or sulfonylurea users (severe hypoglycaemia, as with pramlintide) · History of pancreatitis or gallbladder disease · Gastroparesis or other severe GI motility disorder · Current or past eating disorder (users describe days of not eating and food aversion) · Personal or family history of medullary thyroid carcinoma or MEN 2 when taken as CagriSema or with semaglutide (semaglutide boxed warning) · Under 18
Credible pathways: gallbladder disease from slowed gastric emptying and rapid weight loss (seen at 2.3% vs 1.0%), severe hypoglycaemia when an amylin agonist is combined with insulin (pramlintide's boxed warning), and agonism of the calcitonin receptor, the target of salmon calcitonin, whose long-term use the EMA restricted in 2012 after pooled trials showed 0.7-2.4% more cancers. The cancer link is an association of uncertain causality, and REDEFINE 1 showed no malignancy excess with cagrilintide at 68 weeks (0.7% vs 0.6%), so this stays at 2. SymlinPen (pramlintide) prescribing information ↗EMA calcitonin referral (2012) ↗Cayman Chemical: cagrilintide binds amylin 3 and calcitonin receptors with similar picomolar potency ↗
Data gap 1/3
Not approved anywhere, but controlled trials put about 1,000 people on cagrilintide alone (706 in phase 2, 302 in REDEFINE 1) and several thousand on CagriSema for up to 84 weeks. The data cover Novo's buffered formulation at trial doses, not grey-market powder stacked with retatrutide. Novo Nordisk 2025: cagrilintide monotherapy phase 3 sub-analysis ↗RENEW 1 (NCT07220642) ↗
Silent harm 3/3
Most harms are noticed (not eating, vomiting, fatigue, low mood) or build silently but show on imaging and labs (gallstones, lean-mass loss). The mechanism axis also names the calcitonin-receptor cancer association, and under the rubric a theoretical tumour pathway is a 3 whatever its probability; without that pathway this axis would be a 2. EMA 2012: calcitonin and cancer risk ↗
Twenty-five first-hand reports, almost all with cagri added to retatrutide, tirzepatide or semaglutide. Eight are good (stalls broken, 'appetite crushed', one 50 lb further loss on semaglutide plus 0.25-0.5 mg) and two who took it alone lost weight at 0.2-1 mg. The dominant complaint, in about half the threads, is fatigue or lethargy, sometimes 'debilitating', followed by low mood or anhedonia and, at 0.5-2.5 mg first doses, days of being unable to eat or vomiting. Users converge on starting at 0.1-0.25 mg. Because nearly everyone stacks it, its own effect is hard to separate. Felt nothing: 2 of 25 reports felt little even at 2-3 mg a week; a few more say the effect faded within weeks and needed doses doubled or tripled..
I was on Sema and lost 55 lbs in a year but then stalled. I added on just another .25mg-.5mg of weekly cagri and lost another 50 lbs in 6 months for a total of 105 lbs.
At around 8 weeks I took 1mg of Cag and it was a rough week. I felt full, I felt bloated, and I felt constipated. The constipation was due to lack of eating. I felt overall just down and bad.
Negative1 mg, later 0.5 mg · Injection
added to retatrutide at week 8
Studies
Evidence
Human RCTs — Phase 2 (n=706) and a phase 3 monotherapy arm (n=302); as CagriSema, phase 3 REDEFINE 1, 2 and 4 and an FDA filing with a decision expected in Q4 2026; a standalone phase 3 (RENEW 1) is running; approved nowhere
Caveat
The human trials are solid but were run with Novo's buffered formulation, slow escalation to 2.4 mg and no other weight-loss drug; nearly every Reddit report is cagri stacked on a GLP-1 from unverified vials, so neither its benefits nor its fatigue can be attributed cleanly. Talk of amyloid fibrils forming in badly reconstituted vials is a theoretical worry with no human case reports.
The peptide's chain of amino acids from its start (the N-terminus) to its end, one bead and one letter for each: A alanine, C cysteine, D aspartic acid, E glutamic acid, F phenylalanine, G glycine, H histidine, I isoleucine, K lysine, L leucine, M methionine, N asparagine, P proline, Q glutamine, R arginine, S serine, T threonine, V valine, W tryptophan, Y tyrosine. A modification such as an N-acetyl cap or a C-terminal amide changes how long it lasts in the body. Length tells related peptides apart, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4, and predicts neither effect nor safety.
Report grades
Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.
GlowingPositiveMixedNothingNegativeBad reaction
% positive
The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Peptides rank by this figure, those with no graded report yet after those with one, and Avoid ones after every other entry.
Researcher estimate
No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks after every peptide with graded reports until its own arrive.
Safety tier
Each peptide is tiered Clean, Caution or Avoid from its five risk axes under the chosen safety bar. An Avoid peptide carries a real risk of harm, a plausible route to serious harm rather than mere unpleasantness, so it stays listed with the reason but ranks behind every other entry, however good its reviews.
Safety bar
The safety bar sets how much risk it takes to rate a peptide Avoid. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.
Seen harm
Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.
Mechanism
A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.
Data gap
How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.
Silent harm
Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.
Product
The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin; taken by mouth or in the nose, a pack avoids the injection risks.
Evidence
The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.
Access
How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.
Price per month
Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. Prices are in euros at ECB rates of 2026-10-29, before shipping; the shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.
Dose users report
The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.
Shop trust
Each shop's trust on a 1–5 scale, read from its testing and its reputation: 1 for serious red flags (fabricated COAs, scam reports, impersonation, a closed shop), 2 for no public testing, a new shop or active complaints such as seized parcels, 3 for its own COAs or a short track record, 4 for verified third-party testing or a strong reputation, and 5 for third-party batch reports that name the shop, with years of good independent reputation. A shop without a score counts third-party batch testing as 4, its own COAs as 3 and no public tests as 2.
Best value
Within a category or a goal, a peptide that no other beats on both counts: none is rated more positively for the same or a lower monthly price, and none costs less for the same or a higher rating. The chart joins these into the best-value line; the cheapest of them and the best-rated of them both make it, so the line spans the trade-off from cheap to best. Avoid entries never count, and a peptide needs both a % positive and a price to be compared.
Testing
Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.
Added peptide
Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.