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Eloralintide

2025-2026

C
Animal replicated
Research chemicalPeptide
RouteInjectableGray-market only
Quick take
What it is
Eloralintide (LY3841136) is an investigational once-weekly, long-acting, selective amylin receptor 1 (AMY1R) agonist being developed by Eli Lilly and Company for the treatment of obesity and chronic weight management. It is a 37-amino acid C-terminally amidated peptide analogue of human amylin, engineered with: a Cys(2)-Cys(7) methylene thioacetal bridge for stability; Lys(26) acylated with a C20 fatty diacid chain via two gamma-glutamate linkers (similar lipidation strategy to semaglutide) for albumin binding and once-weekly half-life; and multiple amino acid substitutions that confer selective AMY1R engagement over calcitonin receptor (CTR).
Why people use it
Used primarily for muscle and performance and cognitive support.
What the evidence supports
Eloralintide is in active Phase 3 clinical development as of mid-2026. Unlike cagrilintide (which entered the community research chemical space earlier in its development cycle), eloralintide's Phase 2 completion in August 2025 and Phase 3 initiation in December 2025 make its community availability very limited. A small number of research chemical vendors may carry it as of May 2026, but supply is minimal and quality verification is even more difficult than for more established research chemicals. The synthesis complexity of eloralintide (37 amino acids with a methylene thioacetal bridge and specific lipidation chemistry) is substantially higher than simpler peptides like BPC-157 or TB-500 — the probability of synthesis errors in research chemical production is meaningfully higher. For community users: eloralintide's Phase 3 enrollment creates a realistic opportunity to participate in clinical trials rather than self-administering unverified research chemicals. Phase 3 trials typically compensate participants and provide pharmaceutical-grade product with medical oversight. Searching ClinicalTrials.gov for NCT06230523 follow-on Phase 3 studies is the recommended approach.
If you only read one thing

Eloralintide is the pharmacological hypothesis made flesh: if AMY1R is responsible for amylin's weight-loss-producing satiety effects, and if CTR and AMY3R are responsible for the class liabilities (MTC risk and nausea), then selectively targeting AMY1R should produce a drug with equivalent or superior weight loss and better safety and tolerability. The Phase 2 Lancet (December 2025) provides striking support for the efficacy part: -20.1% weight loss at 9mg in 48 weeks — the highest published figure for an amylin monotherapy, considerably exceeding cagrilintide's -11.5% in its Phase 3. The tolerability data from Phase 2 suggests favorable GI profile relative to non-selective agonists. The MTC question cannot be answered by Phase 2 — it requires long-term Phase 3 human safety data and post-marketing pharmacoepidemiology. Whether the AMY1R selectivity meaningfully de-risks the MTC concern vs cagrilintide's non-selective profile remains to be established. Phase 3 results, expected 2027-2028, will be definitive.

Properties
✓ Human RCTNot injectable
Evidence
CAnimal replicated
The AMY1R Selectivity — The Defining Design Choice
Amylin receptors are heterodimers of the calcitonin receptor (CTR) + one of three RAMP proteins: AMY1R (CTR+RAMP1), AMY2R (CTR+RAMP2), AMY3R (CTR+RAMP3). Cagrilintide (Novo Nordisk) is a non-selective agonist that activates AMY1R, AMY3R, and CTR roughly equivalently. Eloralintide preferentially activates human AMY1R: 12-fold greater potency at AMY1R vs CTR; 11-fold greater vs AMY3R. The clinical significance: AMY1R is primarily responsible for satiety signaling; CTR mediates calcitonin-like effects including the MTC (medullary thyroid carcinoma) rodent signal; reduced CTR engagement theoretically reduces the MTC class concern and may reduce nausea.
Phase 2 Lancet Results (December 2025)
Billings LK et al. The Lancet. Vol 406, Issue 10520, Dec 6, 2025 (published online Nov 6, 2025). NCT06230523. 48-week DBRPC trial; n=263; adults with obesity or overweight + ≥1 comorbidity without T2D; US only. Weight loss by arm: 1mg = -9.5%; 3mg = -12.1%; 6mg = -14.4%; 3-6-9mg escalation = -16.7%; 6-9mg escalation = -18.1%; 9mg = -20.1%; placebo = -0.4%. ALL TREATMENT ARMS MET PRIMARY ENDPOINT. Dose-dependent weight loss from 9.5% to 20.1% vs 0.4% placebo. Well-tolerated; no serious unexpected safety signals.
Phase 3 Status (2025-2026)
Eli Lilly announced Phase 3 initiation immediately after the November 2025 ObesityWeek presentation: 'Lilly will begin enrolling Phase 3 clinical studies for the treatment of obesity next month.' Phase 3 enrollment started December 2025. Phase 3 completion and results: anticipated 2027-2028. Lilly also running Phase 2 combination study with tirzepatide (NCT06603571): eloralintide + tirzepatide in obesity with T2D. No community research chemical or compounded access currently widely available; limited gray-market availability as of May 2026.
Eloralintide vs Cagrilintide — The Key Comparison
Both are long-acting amylin analogues targeting AMY1R for satiety and weight loss. The critical difference: AMY1R selectivity. Eloralintide: AMY1R-selective (12x > CTR); lower conditioned taste avoidance in rats (less nausea signal); Phase 2 Lancet 2025 -20.1% at 9mg. Cagrilintide: non-selective agonist (AMY1R + AMY3R + CTR equally); higher conditioned taste avoidance; Phase 3 REDEFINE 1 cagrilintide monotherapy = -11.5% at 68 weeks. The efficacy comparison is not directly comparable (different Phase and doses) but eloralintide's 20.1% at 48 weeks is markedly higher than cagrilintide's 11.5% at 68 weeks, suggesting AMY1R selectivity may provide superior weight loss as well as better tolerability.
Molecular profile
MW ·
Half-life ·
Class · Peptide
Route ·
~23 min

Eloralintide is the most recently published Lancet compound in this book. Its Phase 2 data appeared in December 2025, Phase 3 enrollment started simultaneously, and the fundamental pharmacological question it is designed to answer is one of the most important in the amylin class: does selective AMY1R activation produce the efficacy of broader amylin agonists with better tolerability and a cleaner safety profile?

Eli Lilly entered the amylin agonist space from a position of pharmaceutical strength — as the developer of tirzepatide (dual GLP-1/GIP agonist, the most efficacious approved obesity drug through 2025), Lilly understood the competitive landscape of obesity pharmacotherapy better than almost anyone. When Novo Nordisk demonstrated with cagrilintide that amylin receptor agonism could produce substantial weight loss as a monotherapy (~11.5% in REDEFINE 1) and spectacular results in combination with semaglutide as CagriSema (-22.7% in REDEFINE 1), the amylin mechanism was validated as a major axis of obesity pharmacotherapy. Lilly's question: can we build a better amylin agonist? The answer was to start from the receptor pharmacology. Cagrilintide activates all three amylin receptor subtypes (AMY1R, AMY3R, CTR) with roughly similar potency. The CTR component provides calcitonin-like effects including the rodent thyroid C-cell signal that generates the MTC black box warning. AMY3R activation may contribute to some of the nausea. AMY1R is primarily responsible for the satiety and food intake reduction that produces weight loss. What if you could target AMY1R specifically?

Lilly's preclinical program at their Discovery Chemistry and Exploratory Medicine and Pharmacology departments identified eloralintide (initially coded LY3841136) as a potent, long-acting AMY1R-selective agonist. The structural engineering: a 37-amino acid amylin analogue with a Cys(2)-Cys(7) methylene thioacetal bridge (replacing the native disulfide bond with a more metabolically stable structure), Lys(26) acylated with a C20 fatty diacid via two gamma-glutamate spacers (the same albumin-binding lipidation strategy as semaglutide for once-weekly dosing), and multiple amino acid substitutions throughout the sequence that shift the receptor selectivity profile toward AMY1R. In cell-based assays using human AMY1R, AMY3R, and CTR, eloralintide showed 12-fold preferential activation of AMY1R over CTR and 11-fold over AMY3R. This selectivity profile is the entire pharmacological premise: all the satiety, less of the thyroid risk and GI nausea.

THE CENTRAL TENSION

Eloralintide is the pharmacological hypothesis made flesh: if AMY1R is responsible for amylin's weight-loss-producing satiety effects, and if CTR and AMY3R are responsible for the class liabilities (MTC risk and nausea), then selectively targeting AMY1R should produce a drug with equivalent or superior weight loss and better safety and tolerability. The Phase 2 Lancet (December 2025) provides striking support for the efficacy part: -20.1% weight loss at 9mg in 48 weeks — the highest published figure for an amylin monotherapy, considerably exceeding cagrilintide's -11.5% in its Phase 3. The tolerability data from Phase 2 suggests favorable GI profile relative to non-selective agonists. The MTC question cannot be answered by Phase 2 — it requires long-term Phase 3 human safety data and post-marketing pharmacoepidemiology. Whether the AMY1R selectivity meaningfully de-risks the MTC concern vs cagrilintide's non-selective profile remains to be established. Phase 3 results, expected 2027-2028, will be definitive.

The Phase 2 Lancet trial safety data was generally favorable. GI adverse events were the most common: nausea, vomiting, and constipation — consistent with the amylin agonist class. Events were predominantly mild to moderate severity. The GI burden appeared somewhat lower than expected based on non-selective comparators — consistent with the AMY1R selectivity hypothesis reducing AMY3R-mediated nausea contribution. Discontinuation rates due to adverse events were not reported as significantly elevated vs placebo. No cases of pancreatitis, gallbladder disease requiring surgery, or medullary thyroid carcinoma were observed — expected given the 48-week duration and n=263; these are rare events requiring long-term data. The overall tolerability profile supports the AMY1R selectivity hypothesis mechanistically, though not definitively proven.

The medullary thyroid carcinoma concern for amylin agonists derives from CTR activation on thyroid C-cells — the same mechanism generating GLP-1 agonists' black box MTC warning. Cagrilintide, as a non-selective agonist that activates CTR equivalently to AMY1R, carries the same CTR-mediated MTC class concern as GLP-1 agonists, and will likely require the same MTC contraindications in its labeling. Eloralintide's 12-fold lower CTR potency theoretically reduces the thyroid C-cell stimulation that generates the rodent MTC signal. Whether this 12-fold reduced CTR engagement translates to meaningful reduction in clinical MTC risk requires: (1) Rodent carcinogenicity studies at therapeutic dose multiples (required for FDA approval); (2) Long-term Phase 3 safety data (Phase 3 duration will be 68-104 weeks); (3) Post-marketing surveillance over years. The practical clinical guidance for current community use: apply the same MTC precautions as for any amylin/calcitonin receptor agonist class compound — personal or family history of MTC or MEN2 should preclude use pending Phase 3 safety data. The AMY1R selectivity is a hypothesis that may prove to be a real clinical advantage — it has not been proven yet.

Eloralintide is a 37-amino acid linear polypeptide in (L) configuration throughout, with the following distinctive structural features: C-terminal amide (NH2): provides metabolic stability against carboxypeptidase degradation and affects receptor binding. Cys(2)-Cys(7) methylene thioacetal bridge: replacing the native amylin disulfide bond with a more metabolically stable methylene thioacetal linkage; this ring structure is critical for maintaining the N-terminal conformation required for AMY1R engagement. Lys(26) lipidation: a C20 saturated linear diacid acylated to the Lys(26) side chain via two gamma-glutamate residues — a fatty acid extension that enables reversible albumin binding in plasma, extending the effective half-life from minutes (native amylin) to approximately one week (eloralintide), enabling once-weekly dosing. This is structurally analogous to how semaglutide uses C18 fatty acid lipidation for once-weekly dosing, with the same albumin-binding pharmacokinetic engineering approach.

Amylin receptors are obligate heterodimers — they only exist and function as a combination of two proteins: the calcitonin receptor (CTR) as the obligate core, paired with one of three receptor activity-modifying proteins (RAMP1, RAMP2, or RAMP3). This creates three functional receptor subtypes: AMY1R (CTR + RAMP1), AMY2R (CTR + RAMP2), AMY3R (CTR + RAMP3). The tissue distribution and functional roles differ by subtype: AMY1R: highest expression in the area postrema and nucleus tractus solitarius (brainstem satiety circuits); the primary mediator of amylin's appetite suppression and energy homeostasis effects. AMY3R: expressed in the brainstem and hypothalamus; may contribute to thermogenesis and metabolic effects; also associated with some of the nausea mechanism. CTR (calcitonin receptor alone): expressed on thyroid C-cells (where it mediates calcitonin's calcium regulatory effects); bone; kidney; the presence of CTR activation in thyroid C-cells drives the rodent MTC signal seen with non-selective agonists. The pharmacological logic of selectivity: if you can activate AMY1R (satiety, weight loss) while minimally engaging AMY3R (partial nausea contribution) and CTR (MTC risk), you should obtain the therapeutic effect with reduced class liabilities.

THE SELECTIVITY NUMBERS — WHAT THEY DO AND DON'T MEAN

Eloralintide's in vitro selectivity profile: AMY1R EC50 = approximately 0.01 nM; CTR EC50 = approximately 0.12 nM (12-fold lower potency); AMY3R EC50 = approximately 0.11 nM (11-fold lower potency). These are in vitro numbers from engineered cell lines selectively expressing individual receptor subtypes. What they establish: eloralintide shows meaningful pharmacological selectivity for AMY1R over CTR and AMY3R in controlled cell-based assays. What they don't establish: (1) Whether in vivo tissue pharmacology replicates the in vitro selectivity — receptor expression levels, local concentrations, and tissue-specific factors all modulate the effective pharmacology in a living system; (2) Whether at clinical doses of 3-9mg/week, the plasma and tissue concentrations of eloralintide remain below the CTR and AMY3R thresholds in thyroid and GI tissue. Doses of 9mg/week likely produce plasma concentrations that approach or exceed the CTR EC50 in some tissues. (3) Whether the AMY1R selectivity genuinely reduces MTC risk in humans — this is a long-duration question that requires Phase 3 safety data. The selectivity is real and meaningful. It is a pharmacological hypothesis, not a proven clinical safety advantage yet.

Eloralintide has the most recently published Phase 2 Lancet trial of any compound in this book. The data is hot off the press — published December 2025 — and represents the current leading edge of the amylin agonist class.

Two Phase 1 studies established eloralintide's safety, pharmacokinetics, and initial weight loss proof of concept. Phase 1 single ascending dose (NCT05295940): n=100 healthy participants; single doses from 0.04mg to 12mg; all doses well-tolerated; pharmacokinetics consistent with once-weekly dosing (half-life ~7 days from albumin-bound lipidated structure); dose-dependent weight loss observed even after single dose. Phase 1 multiple ascending dose (PubMed 41559929, published January 2026): 12-week MAD study in participants with obesity; weekly SubQ dosing; well-tolerated; dose-dependent weight loss at all doses; pharmacokinetics consistent across the dose range. Phase 1 conclusion: excellent safety and tolerability; once-weekly dosing validated; dose-dependent weight loss confirmed as early as Phase 1. These are unusually clean Phase 1 results for an amylin compound.

Billings LK, Hsia S, Bays H, et al. Eloralintide, a selective amylin receptor agonist for the treatment of obesity: a 48-week phase 2, multicentre, double-blind, randomised, placebo-controlled trial. The Lancet. Vol 406, Issue 10520. Published online November 6, 2025; December 6, 2025 issue. NCT06230523. Design: multicentre (46 US research sites); double-blind; randomised; placebo-controlled; 7 treatment arms; 48 weeks. Population: 263 adults (mean age 49.0 years; mean BMI 39.1 kg/m²; 78% female; 78% White); obesity or overweight with ≥1 weight-related comorbidity; without T2D. Randomised in 2:1:1:1:2:1:2 ratio to: placebo; 1mg; 3mg; 6mg; 9mg; 3→6→9mg dose escalation; 6→9mg dose escalation. Completed August 14, 2025.

PRIMARY ENDPOINT RESULTS — Weight change from baseline at 48 weeks: Placebo = -0.4%; 1mg = -9.5%; 3mg = -12.1%; 6mg = -14.4%; 3→6→9mg escalation = -16.7%; 6→9mg escalation = -18.1%; 9mg = -20.1%. All treatment arms met the primary endpoint of superior weight reduction vs placebo. Dose-dependent and escalation-dependent weight loss confirmed. The 9mg arm's -20.1% at 48 weeks is the highest published weight loss for an amylin monotherapy trial. SECONDARY ENDPOINTS: All doses delivered clinically meaningful improvements in body weight (absolute kg), BMI reduction, and waist circumference vs placebo. SAFETY: Generally well-tolerated across all doses. GI adverse events (nausea, vomiting) were the most common; pattern consistent with amylin class effects; most events mild to moderate; concentrated during escalation weeks and resolving at steady-state. No serious unexpected safety signals. No MTC cases (expected — insufficient duration and sample size for rare cancer signal). No significant differences in serious adverse event rates vs placebo.

THE 20.1% FIGURE IN CONTEXT

Eloralintide 9mg at 48 weeks: -20.1% body weight loss vs -0.4% placebo (net -19.7%). This is a remarkably high efficacy signal for a monotherapy amylin agonist. For comparison: semaglutide 2.4mg (Wegovy) at 68 weeks: -14.9% (STEP 1). Tirzepatide 15mg at 72 weeks: -22.5% (SURMOUNT-1). Cagrilintide 2.4mg at 68 weeks: -11.5% (REDEFINE 1 sub-analysis). CagriSema (cagrilintide + semaglutide combined) at 68 weeks: -22.7% (REDEFINE 1). Eloralintide's 9mg result at 48 weeks approaches tirzepatide territory and exceeds CagriSema's combination result — as a monotherapy. Caveats: Phase 2 trials tend to show higher efficacy than Phase 3 (smaller populations, more selected participants, higher engagement); the comparison is not head-to-head; different trial durations (48 vs 68 weeks). Nevertheless, the Phase 2 signal is strikingly strong and provides a compelling foundation for Phase 3.

One of the more promising signals from the preclinical and Phase 1-2 data: eloralintide appears to produce weight loss predominantly from fat mass rather than lean mass. In rat studies (Briere et al., Diabetes 2025, 849-P): eloralintide produced 'improved quality of weight loss' vs cagrilintide — greater fat mass reduction relative to lean mass loss. This is mechanistically consistent with AMY1R selectivity: AMY1R activation primarily reduces food intake and fat oxidation; non-selective agonism of CTR and AMY3R may add effects on other metabolic processes that affect lean mass. If the lean mass preservation signal holds in Phase 3 human data, it would represent a significant clinical advantage over current GLP-1 agonists (where 25-40% of weight loss comes from lean mass) and potentially over cagrilintide.

Lilly is simultaneously running a Phase 2 study (NCT06603571) evaluating eloralintide alone or in combination with tirzepatide for weight management in adults with obesity or overweight and T2D. The rationale: tirzepatide activates GLP-1R and GIP receptors; eloralintide activates AMY1R; all three receptor systems are non-overlapping and address different components of appetite, satiety, and metabolic regulation. A triple combination (GLP-1R + GIPR + AMY1R) would cover the most comprehensive range of metabolic signaling axes explored in obesity pharmacotherapy. If the combination efficacy is additive or synergistic, eloralintide + tirzepatide could represent the next generation beyond CagriSema (GLP-1R + AMY1R).

Evidence

Grade

Key Finding

Limitations

AMY1R selectivity in vitro

A

12-fold > CTR; 11-fold > AMY3R in human cell lines

In vitro; clinical translation uncertain at high therapeutic doses

Conditioned taste avoidance (tolerability signal)

B

Significantly less than cagrilintide in rats (p<0.05)

Rat model; nausea translation to humans not confirmed

Lean mass preservation

B

Greater fat/lean ratio vs cagrilintide (rat + Phase 1-2 data)

Preclinical primary; Phase 3 body composition data pending

Phase 1 safety and PK

B

Well-tolerated; once-weekly dosing validated; dose-dependent WL

n=100 Phase 1; limited diversity; early signal only

Phase 2 weight loss (Lancet Dec 2025)

B

9.5-20.1% WL at 48 weeks; all arms met primary endpoint

Single Phase 2; 263 participants; US only; 78% White; 78% female; Phase 3 needed

Tirzepatide combination (Phase 2 ongoing)

D

Rationale: non-overlapping mechanisms; no published data yet

Phase 2 ongoing; no results published

Long-term safety (MTC, CV)

E — unknown

No MTC or serious CV events in 263 participants at 48 weeks — expected: too short/small for rare events

MTC is a rare cancer with long latency; Phase 3 safety needed

Understanding eloralintide requires understanding the competitive landscape of the amylin agonist class, which has become the most active area of obesity pharmacology development in 2025-2026.

Compound

Developer

Selectivity

Phase

Key WL Data

Differentiator

Pramlintide (Symlin)

Amgen (acquired)

Non-selective; TID meal-time injection

FDA approved (T2D adjunct); not obesity-approved

~5-7% vs placebo (1 year, obesity trials)

First approved amylin analogue; TID dosing limited adoption; superseded by long-acting versions

Cagrilintide (NN9838)

Novo Nordisk

Non-selective (AMY1R + AMY3R + CTR)

Phase 3 complete; NDA filed Q1 2026 as CagriSema

Monotherapy: -11.5% (REDEFINE 1, 68 wks); CagriSema: -22.7%

Advanced as combination (CagriSema = + semaglutide); NDA pending; approved in combination most likely

Eloralintide (LY3841136)

Eli Lilly

AMY1R-selective (12x > CTR)

Phase 3 enrollment started Dec 2025

Phase 2: 9.5-20.1% (48 wks, Lancet Dec 2025)

Best-in-class selectivity hypothesis; highest monotherapy Phase 2 signal; also in combination study with tirzepatide

Petrelintide (NN9748)

Zealand Pharma

Highly selective for AMY1R

Phase 2 (ZUPREME-1 completed early 2026; ZUPREME-2 ongoing)

Phase 1b: 5-7% vs placebo (6 wks); ZUPREME-1 topline 2026

Zealand's selective AMY1R entry; may be 'best-in-class' per Cantor Fitzgerald; head-to-head vs cagrilintide shows +7% margin vs +6%

AZD6234

AstraZeneca

Dual amylin + calcitonin receptor agonist

Phase 1/2

Early data; reported in Lancet amylin review Nov 2025

AZ's entry into amylin space

Met-233

Undisclosed

Amylin receptor agonist

Phase 1/2

Mentioned in Lancet amylin class review

Less characterized in public literature

THE SELECTIVE vs NON-SELECTIVE DEBATE — THE PHARMACOLOGICAL QUESTION OF THE CLASS

The central scientific debate in the amylin agonist class in 2025-2026: does AMY1R selectivity confer meaningful clinical advantages over non-selective agonism? The hypothesis: AMY1R selectivity = less CTR engagement = less MTC risk + less nausea → better tolerability and cleaner safety profile without sacrificing efficacy. The evidence for the hypothesis: (1) Eloralintide's Phase 2 showed 20.1% WL at 9mg — HIGHER than cagrilintide's Phase 3 monotherapy (-11.5%), suggesting selectivity doesn't sacrifice efficacy; (2) Rat conditioned taste avoidance was significantly less for eloralintide vs cagrilintide at equivalent food intake reductions; (3) Lean mass preservation signal suggests fat-specific weight loss. The evidence against complete validation: (1) Phase 2 vs Phase 3 comparisons are not head-to-head; (2) At 9mg/week, plasma concentrations likely approach CTR and AMY3R thresholds — is the selectivity maintained at therapeutic doses in human tissue? (3) MTC risk requires long-term data from both classes to compare. The Phase 3 programs for eloralintide and petrelintide (the two selective AMY1R candidates) will definitively test whether selectivity translates to clinical advantages or whether the non-selective approach (cagrilintide in CagriSema) achieves similar outcomes with the GLP-1 coadministration providing the tolerability improvement.

Eloralintide is in active Phase 3 clinical development as of mid-2026. Unlike cagrilintide (which entered the community research chemical space earlier in its development cycle), eloralintide's Phase 2 completion in August 2025 and Phase 3 initiation in December 2025 make its community availability very limited. A small number of research chemical vendors may carry it as of May 2026, but supply is minimal and quality verification is even more difficult than for more established research chemicals. The synthesis complexity of eloralintide (37 amino acids with a methylene thioacetal bridge and specific lipidation chemistry) is substantially higher than simpler peptides like BPC-157 or TB-500 — the probability of synthesis errors in research chemical production is meaningfully higher. For community users: eloralintide's Phase 3 enrollment creates a realistic opportunity to participate in clinical trials rather than self-administering unverified research chemicals. Phase 3 trials typically compensate participants and provide pharmaceutical-grade product with medical oversight. Searching ClinicalTrials.gov for NCT06230523 follow-on Phase 3 studies is the recommended approach.

THE CASE FOR WAITING — A DIFFERENT RISK-BENEFIT CALCULATION FOR ELORALINTIDE

Unlike cagrilintide (NDA filed Q1 2026; approval expected late 2026/early 2027), eloralintide is 2-3 years from potential FDA approval at the time of writing. The Phase 3 program will: (1) Confirm or modify the efficacy signal from Phase 2 (20.1% is a Phase 2 figure — Phase 3 typically shows somewhat lower efficacy in larger, more diverse populations); (2) Establish the long-term safety profile including MTC data, cardiovascular safety, and bone effects; (3) Define the optimal dosing regimen and dose-response; (4) Determine whether the lean mass preservation signal holds in a large Phase 3 population. For most community users, the appropriate approach is: wait for the Phase 2 combination study with tirzepatide (results expected 2026-2027) and the Phase 3 monotherapy results (2027-2028) before self-administering what is, pharmacologically, a compound at the very beginning of its Phase 3 validation journey. The cagrilintide chapter represents the appropriate near-term amylin option for the community, pending eloralintide's Phase 3 completion.

They are both long-acting amylin analogues designed for once-weekly SubQ dosing for obesity treatment. They are pharmacologically distinct: Cagrilintide is a non-selective agonist activating AMY1R, AMY3R, and CTR with similar potency; it is Novo Nordisk's compound; it has Phase 3 complete (REDEFINE 1/2 Lancet June 2025) and NDA filed for CagriSema. Eloralintide is an AMY1R-selective agonist with 12-fold lower CTR potency; it is Eli Lilly's compound; it has Phase 2 complete (Lancet December 2025) and Phase 3 just started enrollment. Different developers, different selectivity profiles, different development stage.

Petrelintide (NN9748) is Zealand Pharma's AMY1R-selective amylin analogue — not Eli Lilly's. Eloralintide is Lilly's. All three are different AMY1R-focused obesity compounds from different pharmaceutical companies. The amylin class is competitive with multiple well-funded programs pursuing similar mechanisms: Novo Nordisk (cagrilintide/CagriSema), Eli Lilly (eloralintide), Zealand Pharma (petrelintide), AstraZeneca (AZD6234). Each has a distinct molecular structure and development timeline.

Phase 2 results are not Phase 3 results. Phase 2 trials are smaller (n=263), shorter (48 weeks), and conducted in more selected US-based populations (78% female, 78% White). Phase 3 trials are larger (typically n=1,000-5,000+), longer (68-104 weeks), and more diverse. Phase 2 efficacy typically exceeds Phase 3 efficacy. Additionally, the highest dose tested (9mg) showing 20.1% may not become the approved dose — regulatory and tolerability trade-offs at 9mg may lead Lilly to select a lower optimal dose (perhaps 6-9mg with escalation) for Phase 3. The 20.1% is a compelling signal; it is not a prediction of Phase 3 performance.

No. AMY1R selectivity means REDUCED CTR engagement vs non-selective agonists — not zero CTR engagement. Eloralintide at 9mg/week likely achieves tissue concentrations that approach or exceed CTR thresholds in some organs, even with 12-fold lower CTR potency. The MTC risk question requires rodent carcinogenicity studies, long-term Phase 3 human safety, and ultimately post-marketing data. 'AMY1R selective' describes the pharmacological preference of the molecule, not a proven clinical safety advantage. Apply the same MTC precautions as for any amylin class compound pending Phase 3 results.

  • Will Phase 3 confirm the 20.1% weight loss signal from Phase 2, or will the larger, more diverse Phase 3 population show more modest efficacy consistent with other Phase 2-to-Phase 3 attenuation patterns?
  • Does AMY1R selectivity (12-fold > CTR) actually reduce the risk of medullary thyroid carcinoma in humans compared to non-selective agonists like cagrilintide? This requires rodent carcinogenicity studies, long-term Phase 3 safety data, and post-marketing surveillance.
  • Does the lean mass preservation signal from preclinical and early clinical data hold in the Phase 3 population? If eloralintide produces better fat/lean mass ratios than semaglutide or tirzepatide, it represents a substantial clinical advantage for body composition.
  • What does the eloralintide + tirzepatide combination produce in terms of weight loss? The NCT06603571 Phase 2 combination study results are expected 2026-2027 and could position eloralintide as the AMY1R addition to the tirzepatide backbone (analogous to what cagrilintide provides to semaglutide in CagriSema).
  • What is the optimal dose and escalation regimen for Phase 3? The Phase 2 tested 1-9mg; Phase 3 will likely focus on 3-9mg with escalation protocols to optimise the efficacy-tolerability balance.
  • How does eloralintide perform in T2D populations? Phase 2 enrolled obesity without T2D; the tirzepatide combination study addresses T2D; dedicated eloralintide monotherapy in T2D data is pending.

Billings LK, Hsia S, Bays H, Tidemann-Miller B, O'Hagan J, Tham LS, Butler A, Kazda C, Mather KJ, Coskun T. (2025). Eloralintide, a selective amylin receptor agonist for the treatment of obesity: a 48-week phase 2, multicentre, double-blind, randomised, placebo-controlled trial. The Lancet. Volume 406, Issue 10520, pages 2631-2643. doi: 10.1016/S0140-6736(25)02155-5. [Published online Nov 6, 2025; presented at ObesityWeek 2025. Phase 2 DBRPC; n=263; 9.5-20.1% WL vs 0.4% placebo; all arms met primary endpoint; generally well-tolerated; the definitive Phase 2 efficacy and safety paper.]

Briere DA, Long A, Bullock DM, et al. (2025). Eloralintide (LY3841136), a novel amylin receptor agonist for the treatment of obesity: From discovery to clinical proof of concept. Molecular Metabolism. 102:102271. PMC12640043. [Preclinical characterisation including receptor selectivity data (AMY1R 12-fold > CTR, 11-fold > AMY3R); conditioned taste avoidance data showing less aversion than cagrilintide; rat weight loss data; Phase 1 SAD and MAD pharmacokinetics and early efficacy; foundational discovery-to-clinic paper.]

Bhattachar SN, Tham LS, Tidemann-Miller B, et al. (2026, published online Jan 20). Eloralintide, a selective, long-acting amylin receptor agonist for treatment of obesity: Phase 1 proof of concept. PubMed 41559929. [12-week Phase 1 MAD study; n=100; once-weekly dosing; safety, tolerability, PK characterization; dose-dependent weight loss confirmed; clean tolerability profile establishing Phase 2 dose range.]

Lancet. (2025, November issue). Review: Several recently developed long-acting amylin analogues have shown strong efficacy as monotherapy in clinical trials: eloralintide, petrelintide, Met-233 and AZD6234. [Lancet amylin class review placing eloralintide in context of the broader AMY1R agonist competitive landscape.]

Eloralintide is the most pharmacologically interesting Phase 3-entering compound in the amylin space — and the one most community users should probably wait on before considering self-administration.

The honest assessment: Eloralintide has a pharmacological premise (AMY1R selectivity) that is well-reasoned, mechanistically sound, and supported by in vitro data and early clinical signals. The Phase 2 Lancet result (published December 2025) showing 20.1% weight loss at 9mg in 48 weeks is the most striking amylin monotherapy efficacy signal published to date — significantly exceeding cagrilintide's Phase 3 monotherapy performance. The lean mass preservation signal and the conditioned taste avoidance data suggesting better GI tolerability are both directionally positive but preliminary. Phase 3 enrollment just started December 2025. Results are expected 2027-2028. The comparison to wait is the cagrilintide chapter — that compound has completed Phase 3, has Lancet publications from June 2025, and has an NDA pending with approval expected late 2026/early 2027. For the community user interested in amylin receptor agonism for weight management: cagrilintide (or CagriSema when approved) is the near-term option; eloralintide is the one to watch over the next 2-3 years as Phase 3 data emerges.

  • Amylin monotherapy interest now: cagrilintide is the option with the most advanced clinical data (Phase 3 Lancet June 2025); eloralintide Phase 3 results are 2+ years away.
  • Amylin + GLP-1 combination now: CagriSema (cagrilintide + semaglutide) NDA filed Q1 2026; approval expected late 2026/early 2027; the near-term accessible combination.
  • Eloralintide community self-administration (May 2026): very limited supply; complex synthesis; Phase 3 just started; the evidence base is a single Phase 2 trial; the case for waiting is strong compared to any currently approved or near-approval compound.
  • Eloralintide Phase 3 trial participation: the most pharmacologically rational way to access eloralintide currently; search ClinicalTrials.gov for Lilly Phase 3 trials; pharmaceutical-grade product + medical oversight + compensation.
  • The long-term watch: the eloralintide + tirzepatide combination study (NCT06603571) may represent the most mechanistically complete obesity pharmacotherapy ever tested (GLP-1R + GIPR + AMY1R triple receptor coverage); results 2026-2027 will be watched closely by the entire metabolic pharmacology field.

— End of Eloralintide —

THE PEPTIDE BIBLE | Eloralintide | For Research & Educational Purposes Only

Chapter Summary

Eloralintide (LY3841136): Eli Lilly's investigational once-weekly AMY1R-selective amylin receptor agonist. NOT a peptide book research chemical — Phase 3 entering pharmaceutical. Developer: Eli Lilly and Company (Indianapolis). Previous name: LY3841136. NOT Zealand Pharma's petrelintide. STRUCTURE: 37-amino acid C-terminally amidated peptide; Cys(2)-Cys(7) methylene thioacetal bridge (metabolic stability); Lys(26) C20 diacid lipidation via gamma-Glu2 linker (albumin binding; once-weekly half-life ~7 days); L-configuration throughout; single enantiomer. AMY1R SELECTIVITY: 12-fold greater potency at human AMY1R vs CTR; 11-fold > AMY3R; designed to maximise satiety signalling (AMY1R) while minimising MTC risk (CTR) and reducing nausea (AMY3R). Cagrilintide comparison: non-selective (AMY1R ≈ AMY3R ≈ CTR); eloralintide's 12-fold CTR selectivity is the hypothesised safety advantage. PHASE 2 LANCET (Dec 6, 2025; Billings et al.; doi:10.1016/S0140-6736(25)02155-5): NCT06230523; n=263; 48 weeks; 46 US sites; obesity without T2D; 78% female; 78% White. WL results: 1mg = -9.5%; 3mg = -12.1%; 6mg = -14.4%; 3→6→9mg escalation = -16.7%; 6→9mg escalation = -18.1%; 9mg = -20.1%; placebo = -0.4%. ALL ARMS MET PRIMARY ENDPOINT. Generally well-tolerated; GI AEs (nausea, vomiting) mild-moderate; no serious unexpected safety signals. PHASE 1: Phase 1 SAD (NCT05295940) and MAD (PubMed 41559929) established safety, PK (t1/2 ~7 days), and dose-dependent WL. PHASE 3: Enrollment started December 2025; results anticipated 2027-2028. COMBINATION STUDY: NCT06603571 — eloralintide ± tirzepatide in T2D with obesity (Phase 2; GLP-1R + GIPR + AMY1R triple coverage hypothesis). PRECLINICAL ADVANTAGES: Less conditioned taste avoidance than cagrilintide at equivalent food intake reductions (p<0.05); lean mass preservation — greater fat/lean ratio vs cagrilintide in rat models. MTC SAFETY: AMY1R selectivity theoretically reduces CTR-mediated thyroid C-cell stimulation; rodent carcinogenicity and long-term Phase 3 data required to confirm any clinical MTC safety advantage over non-selective agonists; apply standard amylin/calcitonin receptor class precautions pending Phase 3. AMYLIN CLASS LANDSCAPE: Cagrilintide (Novo Nordisk, non-selective, Phase 3 complete, NDA filed as CagriSema); Eloralintide (Lilly, AMY1R-selective, Phase 3 starting); Petrelintide (Zealand, AMY1R-selective, Phase 2 ZUPREME-1 topline 2026). COMMUNITY GUIDANCE: Phase 3 trial participation preferable to research chemical self-administration; cagrilintide is the near-term community amylin option; eloralintide's Phase 3 data (2027-2028) will determine its role.