Cagrilintide

1. Identity

Field	Value	Source
INN	Cagrilintide	[Academic secondary source — PubChem CID 167312356]
Research codes	AM833 / NN9838 / NNC0174-0833	[Peer-reviewed preclinical study — Kruse 2021 J Med Chem]
CAS	1415456-99-3	[Academic secondary source — PubChem CID 167312356]
Molecular formula	C₁₉₄H₃₁₂N₅₄O₅₉S₂	[Academic secondary source — PubChem CID 167312356]
Molecular weight	~4409 g/mol	[Academic secondary source — PubChem CID 167312356]
Peptide class	Long-acting, lipidated (γ-Glu-C20 fatty diacid) amylin analogue	[Peer-reviewed preclinical study — Kruse 2021]
Receptor targets	Non-selective AMY1R / AMY2R / AMY3R + calcitonin receptor (CTR) agonist	[Peer-reviewed preclinical — Fletcher 2021 JPET]; [Academic secondary source — IUPHAR/BPS GtoPdb]
Sequence modifications vs human amylin	N14E, V17R, P37Y; N-terminal acylation with γ-Glu-linked C20 fatty diacid	[Peer-reviewed preclinical study — Kruse 2021]
Half-life (human)	~7–8 days (vs ~50 min for native amylin / pramlintide)	[Peer-reviewed human study — Enebo 2021 Lancet] ⚠️
Approved brand name	None — investigational	[Regulatory document — FDA Drugs@FDA]
Combination product	CagriSema = cagrilintide 2.4 mg + semaglutide 2.4 mg, once-weekly SC	[Regulatory document — Novo Nordisk NDA submission 18 Dec 2025]; [Peer-reviewed human study — Garvey 2025 NEJM] ⚠️
Sponsor / Developer	Novo Nordisk A/S	[Regulatory document — Novo Nordisk Form 6-K SEC filings] ⚠️

2. History and Development

Designed by Novo Nordisk medicinal chemistry (Kruse, Hansen, Dahl et al., J Med Chem 2021;64:11183–11194) to overcome the two principal liabilities of native amylin and pramlintide: amyloidogenic fibril formation and ~50-minute half-life. The N14E / V17R / P37Y substitutions suppress aggregation; the γ-Glu-linked C20 fatty diacid at the N-terminus drives albumin binding and extends half-life to ~7–8 days — the same lipidation strategy as semaglutide (C18 via γGlu+OEG at Lys26) and insulin degludec [Peer-reviewed preclinical — Kruse 2021; Knudsen & Lau, Front Endocrinol 2019].

Clinical development chronology (all Novo Nordisk-sponsored ⚠️ 🔴):

• Phase 1b CagriSema — Enebo 2021 Lancet 397:1736 (n=95; 17.1% at 20 weeks)
• Phase 2 monotherapy dose-finding — Lau 2021 Lancet 398:2160 (n=706; 10.8% at 4.5 mg, 26 weeks)
• Phase 2 CagriSema in T2D — Frias 2023 Lancet 402:720 (n=92; CagriSema 15.6% vs sema 5.1% vs cagri 8.1% at 32 weeks)
• Phase 3 REDEFINE 1 (NCT05567796) — Garvey 2025 NEJM 393:635, published 22 June 2025
• Phase 3 REDEFINE 2 (NCT05394519) — Davies 2025 NEJM 393:648, published 22 June 2025
• Phase 3 REDEFINE 5 (East Asia, NCT05813925) — Ishigaki 2026 Lancet Diabetes Endocrinol 14:450 (n=331; CagriSema 18.4% vs sema 11.9% at 68 weeks)
• Phase 3 REDEFINE 4 (head-to-head vs tirzepatide 15 mg, NCT06131437) — headline 23 February 2026 (n=809, 84 weeks; CagriSema 23.0% vs tirzepatide 25.5% efficacy estimand; non-inferiority NOT met) [Press release — not yet peer-reviewed]
• Phase 3 REIMAGINE 2 (T2D, n=2,728) — headline 2 February 2026 (HbA1c −1.91 pp; weight −14.2% at 68 weeks) [Press release]
• Phase 3 REIMAGINE 1 (T2D, n=180) — Novo Q1 2026 6-K (HbA1c −1.8 pp; weight −13.8% at 40 weeks)
• Phase 3 RENEW monotherapy programme initiated Q4 2025 — RENEW 1 (NCT07220642), RENEW 2 (NCT07220759; first patient dosed 5 Nov 2025)
• CagriSema NDA submitted to FDA on 18 December 2025 based on REDEFINE 1 and REDEFINE 2
• CagriSema co-formulation programme terminated “due to portfolio considerations” per Q1 2026 6-K (6 May 2026). The NDA filing for the existing dosage form remains active; this termination concerns a downstream device/co-formulation programme, not the pivotal submission.

3. Mechanism of Action

Demonstrated (human). Once-weekly SC produces dose-dependent suppression of food intake, delayed gastric emptying, and clinically meaningful weight reduction across Phase 1b, 2, and 3 trials [Enebo 2021; Lau 2021; Garvey 2025; Davies 2025] ⚠️ 🔴. Half-life ~7–8 days in humans supports once-weekly dosing — direct consequence of albumin binding via the γ-Glu-C20 diacid.

Proposed / preclinical. In vitro non-selective high-potency agonism at AMY1R / AMY2R / AMY3R (calcitonin receptor + RAMP1/2/3 heterodimers) and at CTR alone — IC₅₀ 170 pM at hAMY3R and 223 pM at hCTR [Fletcher 2021 JPET]. 2025 cryo-EM structures define the non-selective binding mode [Nat Commun 2025;16:s41467-025-58680-y]. Carvas 2025 (eBioMedicine 117:105836, now peer-reviewed — no longer preprint) established via RAMP1/3-KO mice that AMY1R and AMY3R in the dorsal vagal complex / area postrema mediate the anorectic effect.

Combination rationale with semaglutide. Amylin (satiety / gastric emptying / hindbrain) and GLP-1 (appetite / insulinotropic / hindbrain–hypothalamus) target overlapping but distinct neural circuits; PK studies show no clinically meaningful interaction when co-administered [Enebo 2021].

4. Regulatory Status

4.1 Drug-regulatory status

• US FDA: Cagrilintide monotherapy investigational, no NDA/BLA. CagriSema NDA submitted 18 December 2025. FDA receipt / acceptance-for-filing letter not publicly disclosed in primary FDA documents reviewed. Novo Nordisk Q1 2026 6-K (6 May 2026) projects a “US decision” Q4 2026 but provides no PDUFA goal date. No PDUFA goal date publicly disclosed as of 2026-05-17; no FDA Advisory Committee meeting publicly scheduled. 503A / 503B compounding: No FDA PCAC review of cagrilintide or amylin analogues has been publicly announced; the substance cannot legally be compounded because no FDA-approved reference product exists.
• EMA: No CHMP opinion. CagriSema does not appear as an active MAA in EMA monthly “Applications for new human medicines under evaluation” lists (January–April 2026 reviewed). Novo Nordisk’s 18 December 2025 statement explicitly says CagriSema “is not approved in the US or EU.” No orphan or PRIME designation.
• MHRA, TGA, Health Canada, PMDA, NMPA, MFDS: No marketing authorisation or publicly disclosed submission for CagriSema or cagrilintide monotherapy in any of these jurisdictions as of 2026-05-17. EU CTIS / WHO ICTRP trial registrations exist for the REDEFINE and RENEW programmes.
• WHO Essential Medicines List: Not listed. GRLS (Russia): No registration.

4.2 Anti-doping status

• WADA 2026 Prohibited List: Cagrilintide is not listed by name in the 2026 Prohibited List or the 2026 Monitoring Program. Because cagrilintide has no marketing authorisation for human medicine in any jurisdiction, it falls under the S0 catch-all (Non-Approved Substances) — prohibited at all times (in- and out-of-competition) for WADA-regulated athletes [Anti-doping document — WADA 2026 Prohibited List, S0].
• In-competition / out-of-competition: Both (via S0). TUE eligibility: Not available (no approved medical indication).
• NCAA: Not individually named in the 2025–2026 banned-substances list; falls under the NCAA “peptide hormones, growth factors, related substances, and mimetics” class catch-all.
• DoD / OPSS: Not on the DoD Prohibited Dietary Supplement Ingredients list; for service members, use outside an FDA-regulated clinical trial would be considered investigational drug use.
• Global DRO check date: 2026-05-17 — cagrilintide not individually queryable; status defaults to S0 catch-all.
• TGA scheduling (Australia): Cagrilintide is not individually scheduled in the Therapeutic Goods (Poisons Standard—February 2026) Instrument 2026 (F2026L00060). For context, semaglutide and tirzepatide are S4 (Prescription Only) in Australia.
• Detection window: Not published in indexed literature. Given ~7–8 day plasma half-life and antibody-detectable peptide signature, plausible detection window is several weeks for the parent peptide, but this has not been empirically established in WADA-accredited labs.
• Notable sanctions / precedents: None specific to cagrilintide.

4.3 Last regulatory review

Last regulatory review: 2026-05-17

5. Formulations and Routes

• Subcutaneous injection is the only route in clinical use. Once-weekly, abdomen / thigh / upper arm.
• Phase 2 monotherapy dose range: 0.3, 0.6, 1.2, 1.8, 2.4, 4.5 mg weekly (Lau 2021).
• Phase 3 monotherapy and CagriSema fixed dose: 2.4 mg weekly cagrilintide (alone or with semaglutide 2.4 mg) following 16-week titration.
• No oral, transdermal, intranasal, or other approved or studied routes in indexed literature.

Voice rule: doses listed are study parameters, never recommendations.

6. Preclinical Evidence

• Receptor pharmacology and structure: Fletcher 2021 (JPET) and 2025 cryo-EM (Nat Commun) [Peer-reviewed preclinical].
• Medicinal-chemistry development and rodent PK/PD: Kruse 2021 (J Med Chem) [Peer-reviewed preclinical] ⚠️.
• Rodent food-intake and body-composition studies in DIO mice and rats establishing dose-dependent anorectic and adiposity-reducing effects [Peer-reviewed preclinical — Kruse 2021] ⚠️.
• In vivo receptor dissection: Carvas 2025 (eBioMedicine) — AMY1R/AMY3R RAMP1/3-KO mouse model demonstrating brain amylin receptors 1 and 3 are required for cagrilintide’s anorectic effect [Peer-reviewed preclinical — Carvas 2025].
• Reproductive toxicology, carcinogenicity, and 2-year rodent studies were conducted under Novo Nordisk IND but have not been publicly summarised in peer-reviewed literature as of 2026-05-17; full preclinical packages will be available with any approved FDA label.

7. Clinical Evidence

Cochrane SR: none specific to cagrilintide or CagriSema as of 2026-05-17.

Non-Cochrane SR/MA: Ahmed et al. 2025 (Diabetes Obes Metab, PMID 41834765; DOI 10.1111/dom.70667) — pooled analysis across Lau 2021, Frias 2023, Garvey 2025, Davies 2025. The body of evidence remains small (<10 RCTs); a formal Cochrane review has not yet been undertaken.

Pivotal RCTs (all ⚠️ industry-funded; 🔴 single-sponsor — Novo Nordisk):

Trial	Phase	N	Duration	Population	Key result
Enebo 2021	1b	95	20 wk	Overweight	CagriSema 17.1% vs sema 9.8% vs placebo 1.6%
Lau 2021	2	706	26 wk	BMI ≥30	Cagrilintide 4.5 mg 10.8% vs placebo 3.0%
Frias 2023	2	92	32 wk	T2D + overweight	CagriSema 15.6% vs sema 5.1% vs cagri 8.1%
REDEFINE 1 (NCT05567796)	3	3,417	68 wk	Obesity, no T2D	CagriSema 22.7% (trial product) / 20.4% (treatment policy) vs sema 16.1% vs cagri 11.8% vs placebo 2.3%
REDEFINE 2 (NCT05394519)	3	1,206	68 wk	Obesity + T2D	CagriSema 15.7% (trial product) / 13.7% vs placebo 3.1%
REDEFINE 5 (NCT05813925)	3a	331	68 wk	Japan/Taiwan, BMI ≥27	CagriSema 18.4% vs sema 11.9%
REDEFINE 4 (NCT06131437)	3 (open-label)	809	84 wk	Obesity	CagriSema 23.0% vs tirzepatide 25.5% — non-inferiority NOT met [Press release; not yet peer-reviewed]
REIMAGINE 2	3	2,728	68 wk	T2D	CagriSema HbA1c −1.91 pp, weight −14.2% vs sema 2.4 [Press release]
REIMAGINE 1	3	180	40 wk	T2D	HbA1c −1.8 pp, weight −13.8% vs placebo [Q1 2026 6-K]

All pivotal evidence is Novo Nordisk-sponsored 🔴.

Ongoing trials. REDEFINE 3 CV outcomes (NCT05669755, 7,000 adults with established CVD ± T2D, up to 4.5 years); REDEFINE 8 (104 wk + DXA + 52-wk maintenance vs taper extension); REDEFINE 9 (lower-dose CagriSema 1.7/1.7 and 1.0/1.0 vs placebo); REDEFINE 11 (80 wk + 80-wk extension, first patient early June 2025); high-dose CagriSema 2.4/7.2 mg Phase 3b planned Q2 2026; RENEW 1 and RENEW 2 (cagrilintide monotherapy); pediatric programme initiated.

Head-to-head. REDEFINE 4 vs tirzepatide 15 mg (above) is the only published head-to-head. No data vs retatrutide, MariTide, or survodutide.

7.5 Disputed Claims

There is no substantive adversarial scientific dispute in the peer-reviewed literature on cagrilintide as of 2026-05-17. The dominant epistemic risk is structural single-sponsor dependency (🔴 Novo Nordisk for all pivotal trials), not adversarial dispute.

Three contextual items must be flagged:

1. REDEFINE 1 vs pre-trial expectation (December 2024). Novo Nordisk topline disclosed 22.7% weight loss versus prior management guidance of ≥25%. NVO ADR fell ~20% on 20 December 2024 (CNBC, “Novo Nordisk shares plunge 20% after disappointing trial results; Lilly jumps”); the Copenhagen-listed Novo-B fell 17.8% the same day. This is commercial commentary, not peer-reviewed dispute. The subsequent NEJM publication (22 June 2025) confirmed the primary endpoint was met.
2. REDEFINE 4 failed non-inferiority (February 2026). CagriSema did not demonstrate non-inferiority on weight loss vs tirzepatide 15 mg at 84 weeks. This is a clinical-fact finding, not a methodological dispute; the peer-reviewed primary manuscript has not yet appeared as of 2026-05-17. Open-label design is a methodological limitation worth flagging at publication.
3. Six on-treatment deaths across REDEFINE 1 + 2 including one suicide in each trial, all in the CagriSema arms, are noted in the NEJM publications. Authors state previous GLP-1 RA pharmacovigilance has not supported a causal link with suicidality but note continued concern. This is a flagged safety signal requiring post-marketing surveillance, not a peer-reviewed scientific dispute.

No peer-reviewed 2025–2026 editorials or letters questioning REDEFINE methodology were identified as of 2026-05-17.

7B. Community Evidence Layer

Driving subcommunity. Fat-loss / GLP-1-curious users on the Reddit r/Peptides / r/PeptideUmbrella / r/Retatrutide axis and on glp1forum.com, not longevity-first audiences. Bodybuilding / recomp users (Evolutionary.org, AnabolicMinds) treat cagrilintide as a meal-termination add-on to retatrutide or tirzepatide. There is essentially no standalone-cagrilintide longevity culture — the molecule is almost always discussed as the “C” in a DIY CagriSema or as the appetite-finishing layer on a triple-agonist stack.

Trajectory. Rising slowly, structurally capped. Unlike semaglutide and tirzepatide, which had 503A clinic-compounding channels (Hims, Henry Meds, Mochi), cagrilintide has no legal patient pathway — research-chemical grey market or clinical-trial enrollment only. The 9 September 2025 FDA warning-letter wave — more than 50 letters to U.S. and international GLP-1 compounders and manufacturers (Wilson Sonsini regulatory analysis, accessed 23 September 2025) — explicitly named cagrilintide, foreclosing the 503A route that drove the prior class adoption curve.

Community framing. “Semaglutide tells you don’t eat; cagrilintide tells you stop eating” (Marlon Peralta substack 2025; Derek Pruski substack 2025). The marginal-value debate centers on whether adding cagrilintide to a semaglutide or tirzepatide protocol is worth the GI burden, given REDEFINE 4’s tirzepatide miss.

Community-documented protocols cluster into three patterns: monotherapy (uncommon), DIY CagriSema co-administration with semaglutide (common), and add-on to tirzepatide or retatrutide (the dominant 2025–2026 pattern). The de facto titration chart is skittlet0062’s GLP-1 Forum post — a redrawing of the REDEFINE 1 schedule 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg weekly SC. Most named users describe microdosing in the 0.3–1.0 mg range as a finishing add-on, not running monotherapy to 2.4 mg.

Top claimed effects (sourced):

• “Meal termination / stop eating” qualitative signal — widespread, unusually consistent across independent sources (Peralta, Pruski, Williams, GLP-1 Forum, Evolutionary.org)
• Breaks plateaus on tirzepatide / retatrutide — common (Evolutionary.org JimmyO187: “adding Cagrilintide allowed us to lower the reta dose to 2mgs and get more results”)
• Allows GLP-1 dose reduction while maintaining results — common
• Less “food noise” — common
• 1.0–2.0 lb/week loss when added on top of tirz/reta — common

Reported side effects:

• “Extreme fatigue / cagrilintide tiredness” — signature complaint, unusually consistent (Derek Pruski Substack 2025: “the most frequently reported issue with this compound… overwhelming exhaustion that doesn’t respond to typical interventions”)
• Nausea during titration — common, mirrors trial 20–47% rate
• Injection-site reactions (erythema, nodules, pruritus) — common, attributed to BAC water pH ~5.5 vs acidic-buffer reconstitution
• Constipation, undereating — common when stacked with tirz/reta
• Local granulomas / “hard deposits” — occasional, attributed to incorrect reconstitution
• Potency loss at 3–4 weeks per vial — disputed within community

Community dissent (six splits). (1) Does cagrilintide add anything to semaglutide, or is CagriSema marketing? Resolved in favor of “it adds something, less than Novo claims” — REDEFINE 4 NI miss and David Risinger / Leerink Partners commentary (Dec 2024) cited heavily. (2) Wait for RENEW or DIY now? Community largely moved on from waiting. (3) Pramlintide is cheaper and available, why cagrilintide? Consensus: weekly vs 3× daily decisively favors cagrilintide. (4) pH / fibrillation risk — the most heated debate; Hunter Williams (Beehiiv) explicitly debunks catastrophic-fibrillation narrative (“the main risk… isn’t catastrophic fibrillation — it’s just slightly faster degradation of the peptide”). (5) Vendor trust — no named-batch scandal located specifically for cagrilintide. (6) Cagrilintide vs eloralintide — Eli Lilly’s eloralintide Phase 2 (NCT06230523, 6 Nov 2025) produced 20.1% mean weight loss at 48 weeks at the 9 mg dose in 263 adults (ObesityWeek 2025 / Lancet). Derek Pruski’s substack frames eloralintide as “more compelling scientific development… 20.1% monotherapy weight loss.” Community is starting to position cagrilintide as the incumbent that might be obsoleted before it’s approved.

Vendor landscape. Edge Peptides ($7/mg in 10-pack), Royal Peptides, Expert Peptides ($18/mg), Amino Club / Amino USA (~$4–5/mg with code, Brainflow’s recommended vendor), Peptide Partners (account-gated, LeoLab batch G60147 99.516% Janoshik March 2025), BioEdge Research Labs, Bluum Peptides, NextGen Peptides, HCS-Pharma, Grey Research Peptides (sells a pre-blended “Cagrilintide+Semaglutide 5+5 mg” DIY CagriSema vial — the most explicit grey-market codification of the DIY pattern), plus several account-gated vendors. Peptide Sciences voluntarily shut down 2025 (“After careful consideration, Peptide Sciences has decided to voluntarily shut down operations…”); one of the largest cagrilintide vendors; closure shifted share to Edge, Amino Club, Peptide Partners. Per-mg mode ~$7–10. Cagrilintide is cheaper per mg than retatrutide but more expensive than research-grade tirzepatide as of May 2026.

QC. Janoshik Analytical dominates third-party testing; HPLC-only COAs without mass-spec identity confirmation flagged by Peptidesrated as a yellow flag for amylin-class peptides (identity confirmation non-trivial).

Community Score: 44 / 100 (Usage 9/25; Codification 8/25; Effect consistency 15/25; Time-in-circulation 12/25) — Tier D, upper boundary.

Full community detail is in the Pass 2 community-evidence file (project).

8. Safety Profile

Common AEs (REDEFINE 1). GI AEs 79.6% of CagriSema vs 39.9% placebo: nausea (55% vs 12.6%), constipation (30.7% vs 11.6%), vomiting (26.1% vs 4.1%), diarrhoea class effect. Mostly mild-to-moderate and transient during titration [Garvey 2025] ⚠️.

Serious AE and discontinuation. REDEFINE 1 — discontinuation due to AEs: CagriSema 5.9–6.0% vs placebo 3.5–3.7% vs monotherapy arms ~1.3%; serious AEs more common with CagriSema than semaglutide alone [Garvey 2025]. REDEFINE 2 — discontinuation: CagriSema 8.4% vs placebo 3.0% [Davies 2025]. Six deaths total across REDEFINE 1 + 2, all in CagriSema arms (1 suicide per trial). Causal link not established but flagged. Injection-site reactions more frequent with cagrilintide-containing arms than semaglutide alone or placebo — the widely-circulated William Blair June 2025 analyst note (12% injection-site AE rate attributed primarily to the cagrilintide component) is community-corroborated.

Class warnings carried forward (via semaglutide co-formulation). Thyroid C-cell tumour boxed warning (rodent finding) — semaglutide label. Pancreatitis — class signal. Gallbladder disease (cholelithiasis, cholecystitis) — class signal; one Phase 2 cagrilintide event reported. Diabetic retinopathy worsening — observed in some semaglutide trials.

Cagrilintide-monotherapy-specific signals. In the REDEFINE 1 monotherapy arm and Lau 2021, cagrilintide tolerability was generally favourable; ~1% discontinuation due to nausea vs 0.1% placebo (REDEFINE 1 cagri arm); injection-site reactions more frequent than placebo but not treatment-limiting. Monotherapy GI burden lower than CagriSema or semaglutide monotherapy in REDEFINE 1.

Special populations. No human pregnancy / lactation data; preclinical reproductive toxicology not publicly summarised. Pediatric Phase 3a recently initiated; no published results. Renal / hepatic impairment dedicated PK studies registered on ClinicalTrials.gov; data not publicly summarised in peer-reviewed literature as of 2026-05-17. Elderly subgroup analyses from REDEFINE 1/2 consistent with overall population.

Retraction status. No retractions identified in PubMed or Retraction Watch as of 2026-05-17.

Independent replication. 🔴 No independent (non-Novo Nordisk-sponsored) Phase 3 trials exist. All pivotal human evidence — Enebo 2021, Lau 2021, Frias 2023, REDEFINE 1, REDEFINE 2, REDEFINE 4, REDEFINE 5, REIMAGINE 1, REIMAGINE 2 — was sponsored by Novo Nordisk. This is the dominant structural epistemic risk for the cagrilintide evidence base.

Community-reported AE requiring science-layer attention. The “extreme fatigue / cagrilintide tiredness” signal is widely reported across independent community sources and does not crisply map to any trial-named AE category. It may be (a) a real cagrilintide-specific effect under-detected in trials, (b) a stacking-with-GLP-1 effect, (c) selection bias or expectancy effect, or (d) grey-market product variance. Trial publications do not specifically address it.

9. Drug Interactions

• No labelled interactions (no marketing authorisation).
• Mechanistic class consideration: amylin agonism delays gastric emptying. Class caveats apply for orally administered narrow-therapeutic-index drugs (warfarin, levothyroxine, oral contraceptives, some oral antibiotics) — class-level inference, not cagrilintide-specific data.
• No clinically meaningful PK interaction with semaglutide in CagriSema co-administration phase 1b PK study [Enebo 2021] ⚠️.
• Hypoglycaemia risk when combined with insulin or sulfonylureas — class consideration for any amylin / GLP-1 agonist in patients with T2D.

10. Research Gaps

1. Long-term (>104 wk) safety and durability — REDEFINE 8 (104 wk) and REDEFINE 11 (80 wk + extension) will partially address.
2. Cardiovascular outcomes — REDEFINE 3 CVOT ongoing in 7,000 patients with established CVD; results pending.
3. Renal outcomes — no dedicated trial.
4. Pediatric and pregnancy data — pediatric Phase 3 recently initiated; no pregnancy registry.
5. Independent (non-industry) replication — structurally absent 🔴.
6. Head-to-head vs retatrutide / MariTide / survodutide — none published; REDEFINE 4 (vs tirzepatide) did not show non-inferiority.
7. Weight regain after discontinuation — REDEFINE 8 extension will partially address; otherwise no published CagriSema-specific data.
8. Body composition (lean vs fat mass) — DXA substudy of REDEFINE 1 presented ObesityWeek 2025 (Ravussin, Pennington) showed 66.9% fat / 33.1% lean soft tissue loss among CagriSema recipients; full peer-reviewed analysis pending.
9. Definitive regulatory decisions — FDA decision expected Q4 2026 per Novo Q1 2026 6-K; EMA / other jurisdictions undefined.
10. Cagrilintide monotherapy — Phase 3 RENEW results pending; whether monotherapy will be filed independently of CagriSema is undetermined.
11. Eloralintide as displacement signal — comparative amylin-class data not yet available; community has begun positioning cagrilintide as the incumbent that may be obsoleted before approval.
12. Community-reported “extreme fatigue” — unmapped to any trial-named AE category.

11. Bottom-Line Encyclopedia Note

Cagrilintide is an investigational once-weekly subcutaneous long-acting lipidated amylin / calcitonin-receptor agonist developed by Novo Nordisk. Its lead clinical and regulatory programme is the CagriSema fixed-dose combination with semaglutide 2.4 mg; pivotal Phase 3 evidence (REDEFINE 1 and REDEFINE 2, NEJM 22 June 2025) demonstrated mean weight loss of 22.7% in obesity and 15.7% in obesity + T2D versus placebo. CagriSema’s NDA was submitted to FDA on 18 December 2025 with an anticipated US decision in Q4 2026; no PDUFA date or AdComm has been publicly disclosed and there is no approval in any jurisdiction as of 17 May 2026. REDEFINE 4 (February 2026 press release) failed to demonstrate non-inferiority vs tirzepatide 15 mg. Cagrilintide monotherapy (Phase 3 RENEW) is at earlier stages. The dominant epistemic caveat is single-sponsor structural dependency. Under WADA 2026, cagrilintide is not named but prohibited at all times via the S0 catch-all.

11B. Gap Analysis — Where Science and Community Diverge

Pattern read (per v4 gap matrix): Convergent-with-time-lag — closest match. Science (B/46) and community (D/44) point the same direction (this molecule reduces body weight by amylin-receptor agonism; CagriSema produces ~22% weight loss in obesity at 68 weeks; safety burden is GI-dominated with single-sponsor risk pending). The “high community + low science” cells do not apply: there is no community-ahead-of-science gap (the science is more advanced than the community), no tested-negative-for-marketed-indication pattern (the indication tested is the indication community uses), no indication divergence (community uses for weight loss; trials test weight loss), and no major research-dose : community-dose disconnect (community titration mirrors the trial schedule, capped by the same 2.4 mg ceiling). The gap pattern is best characterised as science-ahead with single-sponsor dependency, community footprint capped by regulatory environment.

Topic	Science Layer	Community Layer	Gap
Weight-loss efficacy (CagriSema)	REDEFINE 1: 22.7% trial-product / 20.4% treatment-policy at 68 wk; REDEFINE 2: 15.7% / 13.7% with T2D	Treated as proven; community uses lower doses (0.3–1.0 mg microdose finishing add-on) more often than the 2.4 mg headline	Aligned on direction. Community runs sub-headline doses because the dominant pattern is add-on to tirz/reta, not monotherapy at trial dose.
REDEFINE 4 non-inferiority miss vs tirzepatide	CagriSema 23.0% vs tirzepatide 25.5% at 84 wk; NI not met; press release only [REFRESHED 2026-05-17]	Community has absorbed this; framing “REDEFINE 4 broke the CagriSema = best-in-class story; the qualitative meal-termination effect is still real”	Notably converged. Unlike retatrutide’s dysesthesia gap (where community was unaware of major safety signal), here the community has fully integrated the most consequential 2026 finding into its protocol logic. This is the cleanest example in Group A of a community-side rapid-integration response.
Single-sponsor dependency	All pivotal trials Novo Nordisk-sponsored 🔴	Treated as acceptable; community accepts the sponsor risk	Community accepts the structural-epistemic risk that science layer flags. Mitigation: Janoshik COA verification of vial identity.
”Extreme fatigue” signal	Not specifically named in trial AE summaries; possibly subsumed in general adverse-event reporting	Unusually consistent across independent sources (Pruski, Peralta, Williams, GLP-1 Forum, Evolutionary.org) — described as a signature complaint distinct from typical GI/nausea pattern	🔴 Community-side signal under-characterised in trials. May be real cagrilintide-specific effect, stacking-with-GLP-1 effect, expectancy, or product variance. Trials do not specifically address.
DIY stack patterns (cagri + tirz; cagri + reta)	Not studied — trials test cagrilintide monotherapy and CagriSema (cagri + sema); no Phase trial covers cagri + tirz or cagri + reta combinations	The dominant 2025–2026 community pattern is add-on to tirzepatide or retatrutide, not standalone or DIY CagriSema	Major stack-pattern gap. Community uses combinations the trials have not evaluated. Mechanistically plausible (amylin + GLP-1/GIP/glucagon non-overlapping appetite circuits) but PK / safety stacking data do not exist outside the cagri + sema configuration.
Injection-site reactions (12% per William Blair note)	Trial AE category; 38% rate cited by PeptideDeck from Phase 2 cohorts	Community-corroborated; widely attributed to BAC water pH ~5.5 vs acidic buffer; Hunter Williams Beehiiv post is the canonical “calm down about fibrillation” reference	Aligned. Both layers agree this is the most common cagrilintide-attributable AE. Community mitigation (acidic-buffer reconstitution) is plausible but not tested.
Pramlintide as historical anchor	Approved as Symlin; pramlintide structural / PK liabilities are the design motivation for cagrilintide	Community knows the pramlintide story second-hand (talking points copied from review articles) and consistently uses it to argue cagrilintide’s improvement	Aligned. Community-second-hand awareness of an approved comparator is functionally adequate.
Eloralintide displacement risk	Phase 2 only; Eli Lilly competitor; not yet evaluated	Active community debate — Pruski substack positions eloralintide as “more compelling scientific development… 20.1% monotherapy weight loss” with better lean-mass preservation	Community-side competitive signal ahead of any published comparative data. Cagrilintide as “incumbent that might be obsoleted before approval” is community-side analysis the science layer has no comment on.
503A compounding pathway	N/A — outside scope	Foreclosed by 9 September 2025 FDA warning-letter wave; cagrilintide explicitly named	Community-only signal that science cannot address. This is the structural cap on cagrilintide’s community footprint — by far the dominant reason cagrilintide sits at D/44 rather than tracking semaglutide’s or tirzepatide’s adoption curve.
Independent clinical replication	None as of 2026-05-17 🔴	Community treats Novo data as sufficient	Community accepts the single-sponsor risk that science flags. Same pattern as retatrutide.

Net characterisation. Cagrilintide sits in a convergent pattern with two informative asymmetries. (1) Unlike retatrutide, the community has already absorbed the most consequential 2026 finding (REDEFINE 4 NI miss) — the time-lag gap that defines retatrutide’s profile is largely absent here. (2) The community surfaces two signals the trials do not: the “extreme fatigue” complaint (under-characterised in trial AE summaries) and the stack-pattern gap (cagri + tirz and cagri + reta combinations are untested combinations of the trial indication). The dominant epistemic risk remains single-sponsor structural dependency, and the dominant audience risk remains foreclosure of the 503A pathway — which caps community adoption regardless of evidence strength.

12. Three Paths

Definition, not prescription. Each path describes practice; none is recommended.

Conservative path — wait. Defined as not engaging until at least one of (a) FDA approval of CagriSema (Novo guidance Q4 2026, no PDUFA confirmed); (b) EMA or other major jurisdiction approval; (c) peer-reviewed publication of REDEFINE 4; (d) Phase 3 RENEW peer-reviewed publication for cagrilintide monotherapy; (e) the first independent (non-Novo) clinical trial; (f) REDEFINE 3 CVOT readout (~5,000+ patient years event-driven). None of these gates are met as of 17 May 2026. Cagrilintide does not meet the conservative bar.

Moderate path — Tier B with supervision (CagriSema configuration only). Defined as treating CagriSema at its B/46 tier with monitoring, accepting single-sponsor risk. Specifies: full pre-cycle baseline bloodwork (lipid panel, HbA1c, fasting glucose, ALT / AST / GGT, lipase, basic metabolic panel, TSH, amylase, resting HR / BP, body composition including DXA where available); on-cycle monitoring every 4–6 weeks; access via clinical-trial enrollment where possible rather than grey-market channels (acknowledging trial enrollment is the only legal patient pathway); titration mirroring REDEFINE 1 schedule with awareness that monotherapy ≠ CagriSema in either efficacy or AE profile; co-administration of resistance training and protein intake at upper community-standard range given the DXA-flagged lean-mass component of weight loss; physician dialogue on injection-site reaction management and on the suicidality signal flagged in REDEFINE 1 + 2 deaths.

High-tolerance path — grey-market with mitigation. Defined as acknowledging that none of the conservative gates are met, that all clinical evidence is single-sponsor 🔴, that the 503A compounding pathway is foreclosed, that DIY stack patterns (cagri + tirz, cagri + reta) are mechanistically plausible but untested, and that the “extreme fatigue” signal is under-characterised. The community mitigation stack as documented: third-party COA verification of the specific vial (Janoshik with mass-spec identity confirmation preferred over HPLC-only); titration starting well below the 0.25 mg headline community-step (sub-mg microdose ramp); cap at 1.0–1.7 mg/week if running as add-on to tirzepatide or retatrutide rather than the 2.4 mg trial-monotherapy dose; structured bloodwork on the optimization-community schedule (4–6 weeks); acidic-buffer reconstitution (per Hunter Williams Beehiiv) rather than standard BAC water for injection-site tolerance; pre-cycle dialogue with a physician willing to monitor without prescribing; awareness that REDEFINE 4 NI miss and eloralintide displacement risk both bear on the long-term value-of-engagement question.

13. Key References

Scientific (Pass 1 layer — full citations in source file):

• Kruse T et al. J Med Chem 2021;64:11183–11194 — discovery and design [Peer-reviewed preclinical] ⚠️
• Fletcher MM et al. JPET 2021;377:417–440 — AM833 receptor pharmacology [Peer-reviewed preclinical] ⚠️
• Enebo LB et al. Lancet 2021;397:1736–1744 — Phase 1b CagriSema [Peer-reviewed human study] ⚠️
• Lau DCW et al. Lancet 2021;398:2160–2172 — Phase 2 monotherapy dose-finding [Peer-reviewed human study] ⚠️
• Frias JP et al. Lancet 2023;402:720–730 — Phase 2 CagriSema in T2D [Peer-reviewed human study] ⚠️
• Garvey WT et al. NEJM 2025;393:635–647 — REDEFINE 1, PMID/DOI 10.1056/NEJMoa2502081, NCT05567796 [Peer-reviewed human study] ⚠️ 🔴
• Davies MJ et al. NEJM 2025;393:648–659 — REDEFINE 2, DOI 10.1056/NEJMoa2502082, NCT05394519 [Peer-reviewed human study] ⚠️ 🔴
• Ishigaki Y et al. Lancet Diabetes Endocrinol 2026;14(6):450–462 — REDEFINE 5, NCT05813925 [Peer-reviewed human study] ⚠️ 🔴
• Carvas AO et al. eBioMedicine 2025;117:105836 — brain amylin receptor mechanism [Peer-reviewed preclinical]
• Liang Y-L et al. Nat Commun 2025;16:s41467-025-58680-y — cryo-EM structures [Peer-reviewed preclinical] ⚠️
• Ahmed et al. Diabetes Obes Metab 2025, PMID 41834765; DOI 10.1111/dom.70667 — SR/MA [Peer-reviewed meta-analysis]
• Novo Nordisk press release, 18 December 2025 — CagriSema NDA submission [Regulatory document]
• Novo Nordisk press release, 23 February 2026 — REDEFINE 4 NI not met [Press release; not peer-reviewed]
• Novo Nordisk press release, 2 February 2026 — REIMAGINE 2 [Press release; not peer-reviewed]
• Novo Nordisk Form 6-K SEC filing, 6 May 2026 — Q1 2026 results [Regulatory document]
• WADA 2026 Prohibited List, section S0 [Anti-doping document]
• TGA Therapeutic Goods (Poisons Standard—February 2026) Instrument F2026L00060 [Regulatory document]
• PubChem CID 167312356; UniProt P10997; IUPHAR/BPS GtoPdb [Academic secondary sources]

Community (Pass 2 layer — full citations in source file):

• GLP-1 Forum thread set (skittlet0062 titration chart; “Adding Cagrilintide to Tirzepatide”; “Cagri + reta” cagri-reta.1270; “Drop Your Numbers”; “Cagrilitide pH”; “Reconstituting agent”; “In Novo’s Own Words: Degradation of Amylin Analogs”)
• Hunter Williams Podcast + Beehiiv (“The Cagrilintide pH Debate”; Q&A March 2026)
• Derek Pruski Substack (“Feeling Exhausted on Cagrilintide?”; “Eloralintide vs Cagrilintide”)
• Marlon Peralta Substack (“Stop Raising Your Retatrutide Dose”)
• Jay Campbell (“Retatrutide vs Cagrilintide” — jaycampbell.com)
• Forj Substack (“Cagrilintide Explained: The Amylin Supercharger”)
• Evolutionary.org “Cagrilintide with GLP1s Semaglutide Tirzepatide Retatrutide” (Community Research, JimmyO187 log)
• Greg Jones / Enovative Wellness YouTube
• BioPharma Dive, 20 December 2024 — Risinger (Leerink Partners) commentary
• Wilson Sonsini regulatory analysis, accessed 23 September 2025 — September 9, 2025 FDA warning letter wave naming cagrilintide
• Eli Lilly press release, 6 November 2025 — eloralintide Phase 2 (NCT06230523)
• Subreddits referenced (not directly retrievable in Pass 2): r/Peptides, r/Peptidesource, r/Retatrutide, r/Biohackers, r/BodyHackGuide — flagged as a follow-up retrieval gap
• Aggregator / vendor sources (commercial motive flagged): Brainflow, Peptides.org, PeptideDeck, SeekPeptides, Peptides.wiki

Pass 2 retrieval limitations preserved (substantive, not workflow):

• Direct Reddit thread retrieval failed during the Pass 2 research session; r/Peptides, r/Peptidesource, r/Retatrutide, r/Biohackers, r/BodyHackGuide host active cagrilintide threads per third-party citation but specific thread titles, dates, and vote counts could not be confirmed at named-source resolution. No Reddit permalinks fabricated.
• GLP-1 Forum direct fetch returned HTTP 403; content retrievable via search-result snippets only. Thread titles, top quotes, and user handles reliable from snippets; full thread context not.
• Several vendor pages account-gated (Peptides Source, Peptide Partners, Pure Lab, Ameano, Arctic Peptides); per-product detail not opened directly.
• Podcast episodes confirmed at episode-title resolution; full transcripts not retrieved.
• Telegram / Discord channels indexed in source pool not accessible to this research methodology.
• Peter Attia, Andrew Huberman, Rhonda Patrick, Bryan Johnson, Brad Stanfield, Layne Norton — no cagrilintide-specific claims by these named figures confirmed at primary-source resolution. Biohacker named-figure layer for cagrilintide is dominated instead by Hunter Williams, Derek Pruski, Marlon Peralta, Jay Campbell, and the Forj substack author — second-tier influencers relative to the calibration anchors for semaglutide/tirzepatide.

14. Audit / Refresh Trail

• Composed: 17 May 2026
• Science-layer source: cagrilintide_sci_2026-05-17_B46_md.md (Pass 1; last refreshed 2026-05-17 vs prior 2026-05-09)
• Community-layer source: cagrilintide_com_2026-05-17_D44_md.md (Pass 2)
• Section 4 Last regulatory review stamp: 2026-05-17
• Next refresh triggers: (a) FDA decision on CagriSema NDA (Novo guidance Q4 2026; PDUFA date if publicly disclosed); (b) FDA Advisory Committee meeting if scheduled; (c) EMA CHMP opinion or MAA submission; (d) REDEFINE 4 peer-reviewed publication; (e) REDEFINE 3 CVOT interim readout; (f) Phase 3 RENEW monotherapy peer-reviewed publication; (g) Eloralintide Phase 3 readout (displacement signal); (h) any retraction of cited primary literature; (i) significant FDA enforcement action affecting cagrilintide research-chemical vendors; (j) direct Reddit thread pull to close the community-source retrieval gap.