EloralintideResearch, Evidence & Safety Profile

Eloralintide (development code LY3841136) is an investigational obesity drug developed by Eli Lilly. It belongs to a mechanistic class called selective amylin receptor agonists — a distinction from earlier amylin analogs such as petrelintide (Zealand/Roche) and cagrilintide (Novo Nordisk), which activate both amylin receptors and calcitonin receptors.

Eloralintide's defining pharmacological feature is its 12-fold selective potency at the amylin 1 receptor (AMY1R) over the calcitonin receptor. The calcitonin receptor is involved in bone metabolism and calcium homeostasis, and its activation has been associated with some of the tolerability limitations seen with the native peptide pramlintide and with the earlier amylin-analog cagrilintide. Eloralintide's selectivity is hypothesized to preserve the metabolic benefits of amylin receptor activation while reducing bone/calcitonin-related signals — though the clinical importance of this distinction is still being characterized.

The Phase 2 trial was published in The Lancet (PMID 41207310, November 2025) and reported dose-dependent weight loss ranging from 9% (1 mg) to 20.1% (9 mg) at 48 weeks versus 0.4% placebo in 263 adults with obesity or overweight without type 2 diabetes. These results prompted Eli Lilly to announce Phase 3 trials initiating by the end of 2025 or early 2026, both as monotherapy and in combination with retatrutide-class incretin therapies.

As of May 2026, eloralintide is investigational and has not been approved by the FDA, EMA, or any other regulatory agency. It is in Phase 3 initiation and available only within approved clinical trial protocols.

Amylin is a 37-amino-acid peptide hormone co-secreted with insulin from pancreatic beta cells. Native amylin has a circulating half-life of minutes and aggregation properties that limit its pharmaceutical usefulness. Eloralintide is a structurally engineered long-acting analog designed for once-weekly subcutaneous dosing and selective activation of a specific amylin receptor subtype.

• Amylin receptor selectivity (AMY1R): Amylin receptors are heterodimeric complexes formed between the calcitonin receptor (CTR) and receptor activity-modifying proteins (RAMPs). Different RAMP subtypes produce different receptor complexes: RAMP1+CTR = AMY1R, RAMP2+CTR = AMY2R, RAMP3+CTR = AMY3R. Eloralintide activates AMY1R 12 times more potently than it activates CTR alone — the selectivity that defines its pharmacological profile relative to unmodified amylin analogs, which activate both the amylin receptor complexes and the calcitonin receptor.
• Satiety and appetite suppression: AMY1R activation in the area postrema, nucleus tractus solitarius, and hypothalamus reduces food intake and promotes satiety. These central effects are mediated through circuits that overlap with but are distinct from GLP-1 receptor signaling pathways — which is why amylin and GLP-1 agonism may be additive or synergistic when combined.
• Gastric emptying: Like pramlintide and other amylin analogs, eloralintide slows gastric emptying, extending the sensation of fullness after meals and reducing post-prandial glucose excursions.
• Leptin sensitivity restoration: Preclinical and clinical evidence across the amylin class suggests that amylin receptor activation partially restores central nervous system sensitivity to leptin — the adipocyte-derived hormone that signals long-term energy stores to the hypothalamus and is typically blunted (leptin resistance) in obesity. Whether eloralintide's AMY1R selectivity affects this mechanism relative to less-selective amylin analogs is not yet published.
• Complementarity with incretin therapies: GLP-1 and GIP receptors operate through different downstream pathways than amylin receptors. Eli Lilly is evaluating eloralintide in combination with retatrutide-class agents as a complementary mechanism approach — the hypothesis being that the combination produces greater weight loss with better tolerability than escalating incretin doses alone.

The following is based on the Phase 2 trial published in The Lancet (PMID 41207310). Phase 3 data does not yet exist.

Phase 2 Lancet Trial (48 weeks, n=263, published November 2025)

• Study design: Phase 2, double-blind, randomized, placebo-controlled trial conducted at 46 research centres in the USA. Adults aged 18–75, BMI ≥30 kg/m² or BMI ≥27 kg/m² with at least one weight-related comorbidity, without type 2 diabetes. Randomized to once-weekly subcutaneous eloralintide (1 mg, 3 mg, 6 mg, 9 mg, 6→9 mg escalation, or 3→9 mg escalation) or placebo for 48 weeks. Lead author: Billings LK et al.
• Dose-response weight loss (efficacy estimand):
  • 1 mg: −9.0%
  • 3 mg: −12.3%
  • 6 mg: −17.5%
  • 9 mg: −20.1%
  • 6→9 mg escalation: −19.7%
  • 3→9 mg escalation: −16.0%
  • Placebo: −0.4%
• Tolerability: Nausea was dose-dependent, occurring in 11–64% of participants depending on dose group (14% in placebo). Fatigue was also dose-dependent (0–46% depending on dose, 12% in placebo). The most common adverse events with eloralintide were gastrointestinal — consistent with the amylin class and with other injectable weight-management agents. No new safety signals were identified in Phase 2.

Context: amylin class weight-loss comparison

Eloralintide's Phase 2 9 mg figure (20.1% at 48 weeks) compares favorably with petrelintide Phase 2 ZUPREME-1 (~10.7% at 42 weeks) and cagrilintide Phase 2 (~15.6% at 26 weeks when combined with semaglutide as CagriSema). However, cross-trial comparisons are unreliable due to different study designs, populations, dose-escalation protocols, and durations. Phase 3 head-to-head data between these agents do not exist.

Eloralintide's 20.1% Phase 2 figure also approaches incretin-class Phase 2 figures for retatrutide (24.2% at 48 weeks) and tirzepatide Phase 3 (up to 22.5% at 72 weeks), which is notable for a mechanism-class that historically achieved 5–7% weight loss (pramlintide in Phase 3). The magnitude likely reflects the improved pharmacokinetics enabling once-weekly dosing and full dose escalation.

Eloralintide's Phase 2 safety profile is defined by dose-dependent gastrointestinal adverse events. Phase 3 data does not yet exist.

• Nausea: The most common adverse event in Phase 2. Nausea occurred in 11–64% of participants depending on dose group, versus 14% in placebo. The dose-dependence indicates that titration speed and dose selection will be critical considerations in Phase 3 design.
• Fatigue: Reported in 0–46% depending on dose (12% in placebo). Dose-dependent and likely related to both CNS amylin receptor activation and the metabolic shift during weight loss.
• Injection site reactions: Expected for once-weekly subcutaneous administration; mild redness and transient irritation.
• Hypoglycemia: As with pramlintide and other amylin analogs, risk is low from eloralintide alone. Risk is substantially higher when combined with insulin or insulin secretagogues (sulfonylureas). The native amylin analog pramlintide carries an FDA boxed warning for severe hypoglycemia when co-administered with insulin — a class-level signal relevant to eloralintide.
• Bone/calcitonin effects: A theoretical consideration: eloralintide's AMY1R selectivity was designed partly to reduce activation of the calcitonin receptor, which plays a role in bone turnover. Whether the selective profile meaningfully reduces bone-related signals compared with less-selective amylin analogs (cagrilintide, petrelintide) has not been reported in clinical data.
• Long-term safety: Phase 2 was 48 weeks in 263 participants. Long-term safety, cardiovascular outcomes, and bone metabolism effects are not yet characterized. Phase 3 trials will provide 68–80+ week data in larger populations.

Disclaimer: Eloralintide is investigational and not approved for any indication. The following reflects Phase 2 trial doses for educational purposes only. These are not recommendations for self-administration.

Phase 2 evaluated single fixed doses (1 mg, 3 mg, 6 mg, 9 mg) and two escalation schemes (3→9 mg and 6→9 mg) over 48 weeks. The 9 mg and 6→9 mg arms achieved similar weight loss (~20%), suggesting that escalation may enable better tolerability without sacrificing efficacy — a common finding across the GLP-1 and amylin drug classes. Phase 3 dose selection will be informed by the Phase 2 dose-response and tolerability data.

Eloralintide's clinical development is led by Eli Lilly. As of May 2026, the foundational data set is one peer-reviewed Phase 2 Lancet publication, with Phase 3 trials initiating.

• Phase 2 Lancet trial (PMID 41207310, published November 2025): Billings LK 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. 2025; S0140-6736(25)02155-5. n=263, 46 US research centres, 48 weeks, once-weekly subcutaneous eloralintide at 1–9 mg doses vs placebo. Doses from 1→9 mg all met primary endpoint. Up to 20.1% weight loss at 9 mg vs 0.4% placebo. Dose-dependent nausea was the primary tolerability concern.
• AMY1R selectivity pharmacology (PMID 41559929): A companion publication characterizing eloralintide's receptor selectivity profile — 12× potency at AMY1R over calcitonin receptor — and the structural basis for selective agonism. Published in Nature Metabolism or similar (confirm at PubMed).
• Phase 3 monotherapy (initiating late 2025/early 2026): Eli Lilly announced plans for Phase 3 monotherapy trials for obesity following the Lancet Phase 2 publication. Specific trial registration and endpoint design will be disclosed on ClinicalTrials.gov.
• Phase 3 combination with retatrutide-class agents (planned): Eli Lilly is also evaluating eloralintide as a complementary add-on to incretin therapies — the hypothesis being that AMY1R agonism and GLP-1/GIP/glucagon agonism act through different neural circuits and may produce greater weight loss in combination than either class at the same doses. Combination trial design has not yet been publicly specified.
• Amylin class context: Eloralintide enters a competitive amylin landscape that includes petrelintide (Zealand/Roche, Phase 3 announced H2 2026), cagrilintide (Novo Nordisk, in combination with semaglutide as CagriSema), and the legacy agent pramlintide (Symlin, FDA-approved for diabetes since 2005). The shared class hypothesis is that amylin agonism plus incretin agonism is more effective than incretin agonism alone — driving multiple pharmaceutical companies to run amylin + incretin combination trials simultaneously.

As of May 2026, eloralintide is an investigational compound. It has not received FDA approval, EMA approval, or approval from any other regulatory agency.

• United States: Investigational. Available only within approved Phase 3 clinical trial protocols. It is a proprietary peptide developed under Eli Lilly's manufacturing and IND framework and is not a compoundable generic peptide.
• European Union / other markets: No regulatory status. Phase 3 global development is anticipated but trial geography has not been announced.
• Expected timeline: Phase 3 trials initiating late 2025/early 2026. Phase 3 weight management trials typically run 68–80+ weeks. An NDA filing would not be expected before 2027–2028 at the earliest. This is speculative and entirely dependent on Phase 3 outcomes and regulatory review.
• Grey market access: Any source claiming to supply eloralintide outside of an approved clinical trial should be treated with serious skepticism. Identity, purity, and safety cannot be verified, and the legal and health risks to individuals sourcing unverified material are significant.