Eloralintide
LY3841136 · ENLIGHTEN Program · EloraTZP
An investigational amylin receptor agonist from Eli Lilly, injected once a week. In a 48-week phase 2 trial in adults without diabetes, weight fell by up to 20% under the efficacy estimand, against 0.4% on placebo. It is now in five phase 3 trials, and Lilly is also developing it with tirzepatide as EloraTZP.
What is it?
Eloralintide (LY3841136) is an investigational once-weekly injection developed by Eli Lilly for weight management. It is an amylin receptor agonist: it mimics amylin, a hormone the pancreas releases with insulin after meals, which helps end a meal by signalling fullness. Lilly designed it to favour the amylin receptor over the closely related calcitonin receptor, and in cell assays it preferred the human AMY1 receptor about 12-fold.
Its phase 2 trial, published in The Lancet in November 2025, gave 263 adults with obesity or overweight and no diabetes one of six dose regimens or placebo for 48 weeks. Under the efficacy estimand, which assumes everyone stayed on treatment, weight fell by 9% on 1 mg and by up to 20% on 9 mg, against 0.4% on placebo. Nausea depended heavily on how the dose was reached, and fatigue was common at the higher doses.
Lilly began five phase 3 trials, the ENLIGHTEN programme, between December 2025 and February 2026, each measuring weight at 64 weeks. In a separate phase 2b trial it combined eloralintide with tirzepatide, a pairing it calls EloraTZP, in adults with type 2 diabetes; those results were announced on September 30, 2026 and have not yet been published. Eloralintide is approved nowhere.
Mechanism of Action
Eloralintide works through the amylin system rather than the GLP-1 system that semaglutide and tirzepatide use. Amylin acts in the brain to end meals and slow eating, which is why amylin drugs are being tested both alone and alongside incretin drugs.
Amylin Receptor Agonism
Amylin receptors are the calcitonin receptor paired with one of three accessory proteins (RAMP1 to 3), forming AMY1, AMY2 and AMY3. Eloralintide activates them, and Lilly says its effect on weight is likely mediated by satiety, the feeling of fullness, which reduces how much people eat.
Selectivity Over the Calcitonin Receptor
In cell lines expressing single human receptors, eloralintide activated AMY1 12 times more potently than the calcitonin receptor and 11 times more potently than AMY3. In rats it activated AMY1 and AMY3 more potently than the calcitonin receptor and caused less conditioned taste avoidance than cagrilintide, a non-selective amylin agonist. Those last findings are animal data: whether selectivity improves tolerability in people is the question the human trials are answering.
Once-Weekly Design
Lys26 carries a C20 fatty diacid on a two-glutamate linker, the kind of lipidation that lets long-acting peptides bind reversibly to albumin and stay in the blood for days. Pharmacokinetics in rats, monkeys and people support once-weekly dosing, and in the 12-week phase 1 study exposure rose in proportion to dose.
Combination With Incretins
EloraTZP pairs eloralintide with tirzepatide, which acts on the GIP and GLP-1 receptors, so that three hormone pathways are engaged at once. In the phase 2b trial the two drugs were given as separate injections; Lilly plans a single-injection co-formulation for phase 3.
Published Research
Three primary papers have been published, all funded by Eli Lilly: the phase 2 trial in The Lancet and two phase 1 reports. The EloraTZP phase 2b has been presented but not published. As of October 2, 2026, the five ENLIGHTEN phase 3 trials are recruiting, with primary completion dates from January to June 2028 on ClinicalTrials.gov.
Phase 2: 48 Weeks in Obesity Without Diabetes
Billings et al. (Lancet 2025). 263 adults at 46 US centres, with obesity or overweight and at least one weight-related condition and no type 2 diabetes (mean BMI 39.1), took placebo or eloralintide weekly for 48 weeks: fixed 1, 3, 6 or 9 mg, or escalation to 9 mg from 6 mg or from 3 mg. Under the efficacy estimand weight fell 9% (1 mg), 12% (3 mg), 18% (6 mg), 20% (9 mg), 20% (6 to 9 mg) and 16% (3 to 9 mg), against 0.4% on placebo. Nausea ranged from 11% to 64% across the groups (14% on placebo), and fatigue reached 43% on 9 mg and 46% on 6 to 9 mg (12% on placebo).
Phase 1: 12 Weeks of Multiple Doses Without Escalation
Bhattachar et al. (Diabetes Obes Metab 2026). 100 people with obesity or overweight (mean age 44, mean BMI 32.6) at three US centres received weekly eloralintide or placebo in five ascending-dose cohorts, started at the full dose. At week 12, mean weight loss ranged from 2.6% to 11.3% across the dose groups. Decreased appetite (19%), headache (12%) and fatigue (11%) were the most common adverse events; diarrhoea (10%), nausea (8%) and vomiting (4%) were infrequent. There were no deaths and one serious adverse event, judged unrelated.
Discovery and First Single Doses in People
Briere et al. (Mol Metab 2025). In cell assays eloralintide preferred the human AMY1 receptor (12-fold over the calcitonin receptor); in rats it caused less taste avoidance than cagrilintide and cut weight mostly through fat loss (animal data). In the first trial in people, 48 healthy participants (mean BMI 27.5) received single doses from 0.04 to 12 mg or placebo: 16 adverse events in 9 participants, 15 of them mild, and weight four weeks after one dose of 12 mg was 4.4% lower, against a 0.6% gain on placebo.
Dosing Data
Eloralintide is INVESTIGATIONAL and approved nowhere as of October 2, 2026. The doses below are the ones tested in published trials, listed for reference only; there is no approved dose.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Side Effects & Contraindications
Reported Side Effects
From the phase 2 trial (Lancet 2025) and its registry record, and the two phase 1 reports. Gastrointestinal effects depended strongly on the starting dose, and fatigue stood out:
Contraindications & Cautions
Eloralintide has no label, so no formal contraindications exist. The phase 2 trial excluded people with the following, which is a guide to who has not been studied rather than a list of proven risks:
Legal Status
Eloralintide is INVESTIGATIONAL everywhere. It has no marketing authorisation in any country as of October 2, 2026, and Lilly has announced no filing date. Eloralintide offered for sale outside a clinical trial is not a regulated medicine.
Frequently Asked Questions
?What is eloralintide?
Eloralintide (LY3841136) is an investigational once-weekly injection from Eli Lilly that mimics amylin, a hormone that signals fullness after meals. It is being developed for weight management and is approved nowhere.
?How does eloralintide work?
It activates amylin receptors, which help end meals, and it was designed to favour the amylin receptor over the related calcitonin receptor: in cell assays it preferred the human AMY1 receptor about 12-fold. Lilly says its effect on weight is likely mediated by satiety.
?How much weight did people lose on eloralintide?
In the 48-week phase 2 trial in adults without diabetes, weight fell by 9% on 1 mg and up to 20% on 9 mg, against 0.4% on placebo. Those figures use the efficacy estimand, which assumes everyone stayed on treatment.
?What are the side effects of eloralintide?
Nausea and fatigue were the most common. Nausea depended on the starting dose: 64% when treatment began at 6 mg and 25% when the dose climbed gradually from 3 mg, against 14% on placebo. Fatigue reached 43% on 9 mg (12% on placebo).
?What is EloraTZP?
EloraTZP is Lilly's name for eloralintide combined with tirzepatide. In a phase 2b trial in adults with type 2 diabetes, the top combination cut weight 23.3% at 48 weeks under the efficacy estimand, against 14.8% on tirzepatide 15 mg; up to 27% of a combination group stopped for side effects. Lilly plans phase 3 trials of a single-injection version by the end of 2026.
?How is eloralintide different from cagrilintide?
Both are long-acting amylin analogues, but cagrilintide also activates the calcitonin receptor, while eloralintide was designed to favour amylin receptors. In rats eloralintide caused less taste avoidance than cagrilintide; no trial has compared the two in people, so differences in human results cannot be judged across trials.
?Is eloralintide FDA-approved?
No. As of October 2, 2026 it is in phase 3 trials and approved by no regulator anywhere. The five ENLIGHTEN trials list primary completion dates in 2028, and Lilly has announced no filing date.
?Can I buy eloralintide?
Not legitimately. It is available only inside Eli Lilly's clinical trials. Products sold online as eloralintide are not regulated medicines, and their contents are unverified.
References
- [clinical-trial] 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." Lancet, 2025;406(10520):2631-2643. PMID: 41207310.
- [clinical-trial] Bhattachar S, et al. "Eloralintide, a selective, long-acting amylin receptor agonist for treatment of obesity: Phase 1 proof of concept." Diabetes Obes Metab, 2026;28(4):2651-2660. PMID: 41559929.
- [pubmed] Briere DA, et al. "Eloralintide (LY3841136), a novel amylin receptor agonist for the treatment of obesity: From discovery to clinical proof of concept." Mol Metab, 2025;102:102271. PMID: 41109426.
- [clinicaltrials] ClinicalTrials.gov NCT06230523: eloralintide versus placebo in adults with obesity or overweight, 48 weeks; results posted June 24, 2026 (read October 2, 2026).
- [clinicaltrials] ClinicalTrials.gov NCT06603571: eloralintide and tirzepatide, alone or in combination, in adults with obesity or overweight and type 2 diabetes (read October 2, 2026).
- [clinicaltrials] ClinicalTrials.gov: ENLIGHTEN-1, -2, -3, -4 and -6 (NCT07321886, NCT07282600, NCT07369011, NCT07353931, NCT07392190), phase 3 (read October 2, 2026).
- [other] Eli Lilly and Company. EloraTZP (combination of eloralintide and tirzepatide) phase 2b results, news release, September 30, 2026 (read October 2, 2026).
- [other] FDA Global Substance Registration System, UNII 73G3354J8W (eloralintide), and KEGG DRUG D12886 (read October 2, 2026).
Sources & Citations
Structure from the FDA Global Substance Registration System (UNII 73G3354J8W) and KEGG DRUG (D12886); the molecular formula was re-derived from the published structure and matches KEGG to the fourth decimal of the monoisotopic mass. Trial results from the three published papers, read at their abstracts on PubMed, and the ClinicalTrials.gov records; EloraTZP results from Eli Lilly's September 30, 2026 announcement. All read October 2, 2026.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.