Eloralintide: what it is, phase 2 results, side effects and approval status

Eloralintide, developed by Eli Lilly under the code LY3841136, is a synthetic analogue of amylin, a hormone the pancreas releases alongside insulin after meals that promotes fullness and slows stomach emptying. Lilly’s discovery paper, published in Molecular Metabolism in 2025, describes it as an amylin receptor agonist that in cell assays activates the human amylin 1 receptor about 12 times more potently than the calcitonin receptor and 11 times more potently than the amylin 3 receptor ^[1]. That selectivity is the point of the design.

Amylin does not have a receptor of its own. Amylin receptors are formed when the calcitonin receptor pairs with one of three receptor activity-modifying proteins, giving the subtypes AMY1, AMY2 and AMY3 ^[5]. The other long-acting amylin drug in late-stage development, cagrilintide from Novo Nordisk, activates the calcitonin receptor as well as the amylin receptors. Eloralintide was built to avoid that. In rats, it caused significantly less conditioned taste avoidance, a laboratory proxy for nausea, than cagrilintide ^[1].

Unlike semaglutide, tirzepatide or retatrutide, the eloralintide peptide does not act on the GLP-1 receptor at all. It is an alternative hormone pathway to the incretin drugs rather than a variation on them. Because of its phase 2 results it is now listed by online research suppliers; those vials are not Lilly’s trial product and no licensed version exists. See what research peptides are.

Amylin acts mainly on the area postrema and other brain regions outside the blood-brain barrier to increase satiety, and it slows gastric emptying and suppresses glucagon release after meals ^[5]. An agonist that lasts a week keeps that satiety signal switched on continuously. In diet-induced obese rats, eloralintide reduced food intake and body weight in a dose-dependent way, and the weight lost was mainly fat mass. Its pharmacokinetics in rats and monkeys supported once-weekly dosing ^[1].

The argument for receptor selectivity is tolerability. Calcitonin receptor activation is thought to contribute to nausea, and cagrilintide, which is not selective, produced nausea in 20% to 47% of participants in its phase 2 trial depending on dose ^[6]. Eloralintide’s phase 1 multiple-dose study reported diarrhoea in 10%, nausea in 8% and vomiting in 4% of participants, which the investigators described as infrequent ^[2]. Whether that advantage holds at the doses that produce large weight loss is less clear from the phase 2 trial, discussed below.

A 2026 review of the early clinical data notes that eloralintide reduced pulse rate in trials, in contrast to the heart rate increase seen with GLP-1 receptor agonists, along with reductions in blood pressure, inflammatory markers and lipids and preferential loss of fat mass. The same review cautions that all of this comes from small, short phase 1 and 2 studies and that no amylin agonist has been tested in a cardiovascular outcomes trial ^[4].

The first human data were single ascending doses from 0.04 mg to 12 mg in 48 healthy participants with a mean BMI of 27.5. Nine participants on eloralintide reported 16 adverse events, 15 of them mild; two participants reported four gastrointestinal events, including one moderate episode of vomiting. Four weeks after a single 4 mg or 12 mg dose, weight had changed by −2.5% and −4.4% respectively against +0.6% on placebo ^[1].

The phase 1 multiple ascending dose study, published in 2026, gave once-weekly eloralintide without any dose escalation to 100 adults with obesity or overweight at three US sites between March 2022 and January 2024. Drug exposure was proportional to dose. At week 12, weight had fallen by 2.6% to 11.3% across the dose groups. The most common adverse events were decreased appetite (19%), headache (12%), fatigue (11%) and COVID-19 (11%). One serious adverse event, in the 6 mg cohort, was judged unrelated to the drug ^[2].

Eloralintide results from phase 2 are the main evidence. The trial, published in The Lancet in 2025, enrolled 263 adults with a BMI of 30 or more, or 27 or more with a weight-related condition, without type 2 diabetes, at 46 US centres. Mean weight was 109.1 kg and mean BMI 39.1, and 78% were women. Participants were randomised to weekly placebo or eloralintide at 1 mg, 3 mg, 6 mg or 9 mg without escalation, or to escalation schemes of 6 to 9 mg or 3 to 9 mg, for 48 weeks. Using the efficacy estimand, weight changed by −9% on 1 mg, −12% on 3 mg, −18% on 6 mg, −20% on 9 mg, −20% on 6 to 9 mg and −16% on 3 to 9 mg, against −0.4% on placebo ^[3].

Those percentages place eloralintide alone in the range reported for the licensed drugs. For context, cagrilintide alone produced up to 10.8% at 26 weeks in its phase 2 trial ^[6], and Novo Nordisk’s CagriSema combination of cagrilintide with semaglutide produced 20.4% at 68 weeks in phase 3 ^[7]. Eloralintide reached about 20% at 48 weeks on its own, in a smaller trial with wide confidence intervals, and phase 3 results will show whether that holds.

Lilly began phase 3 in early 2026. ENLIGHTEN-1 is a placebo-controlled trial of once-weekly eloralintide in about 1,980 adults with obesity or overweight without type 2 diabetes; the registry describes a main phase of about 75 weeks, with participants who have prediabetes continuing for a further two years, and lists an estimated primary completion in March 2028 ^[8]. ENLIGHTEN-2 enrols about 1,035 adults with obesity or overweight and type 2 diabetes ^[9].

Two further phase 3 trials test specific settings: one in about 900 adults with knee osteoarthritis pain and obesity or overweight ^[10], and one in about 900 adults who still have obesity while being treated with a weekly incretin drug, which will show whether adding eloralintide to a GLP-1-based medicine produces further weight loss ^[11]. Lilly is also running a phase 2 trial of eloralintide alone and in combination with another of its compounds, macupatide (LY3532226) ^[12]. As of September 2026 none of these had reported results, and eloralintide has no completed phase 3 trial.

The trials report fixed time points rather than onset. Four weeks after a single 12 mg dose, weight had fallen 4.4% ^[1]; after 12 weekly doses in the phase 1 study, 2.6% to 11.3% depending on dose ^[2]; and after 48 weeks in phase 2, 9% to 20% ^[3]. The phase 2 trial was unusual in giving fixed doses from the first week in most arms, without escalation, so its early weeks were at the full dose rather than a starting dose ^[3].

The discovery paper states that eloralintide’s pharmacokinetic profile supports once-weekly dosing ^[1], but we did not find a half-life figure in the published abstracts.

The doses studied are single doses of 0.04 mg to 12 mg in the first-in-human study ^[1]; once-weekly doses without escalation in five multiple ascending dose cohorts in the phase 1 study, which reported a serious adverse event in the 6 mg cohort and so included at least that dose ^[2]; and 1 mg, 3 mg, 6 mg and 9 mg once weekly, fixed or escalated from 3 mg or 6 mg to 9 mg, in the phase 2 trial ^[3]. The phase 3 trials use once-weekly dosing but their dose arms are not described in the registry entries we reviewed ^{[8] [9]}.

These are reported for information only. There is no approved eloralintide dosage because there is no approved product, and the trial doses were given under medical supervision in a study designed to find out which dose works. The phase 2 trial itself found that starting at 3 mg and escalating to 9 mg gave less weight loss at 48 weeks (16%) than starting at 9 mg (20%), and that 6 mg without escalation had the highest nausea rate, so the relationship between dose, escalation and effect is not simple ^[3]. Research vials labelled with a milligram amount have not been shown to contain that amount. Our peptide calculator explains reconstitution arithmetic, and the bacteriostatic water guide covers the diluent.

Every published eloralintide study used subcutaneous injection, once weekly in the multiple-dose trials ^{[1] [2] [3]}. Research suppliers sell it as a freeze-dried powder for reconstitution, which has not been used in any trial. No oral form has been studied.

The eloralintide side effects in the phase 2 trial were led by nausea and fatigue, and both rose with dose. Nausea affected 11% on 1 mg, 13% on 3 mg, 64% on 6 mg, 33% on 9 mg, 54% on 6 to 9 mg and 25% on 3 to 9 mg, against 14% on placebo. Fatigue affected 0%, 13%, 29%, 43%, 46% and 21% respectively, against 12% on placebo ^[3]. The 64% nausea rate on fixed 6 mg is not the low figure the selectivity argument would predict, and the 43% to 46% fatigue rate on the higher doses is a finding that GLP-1 drug trials do not usually report at that level, which is why eloralintide fatigue has become a common search.

In the phase 1 multiple-dose study, gastrointestinal events were infrequent, decreased appetite was the most common adverse event at 19%, and fatigue was reported by 11% ^[2]. In the single-dose study, most adverse events were mild ^[1]. No deaths were reported in any published eloralintide trial. The 2026 review notes a reduction in pulse rate rather than the increase seen with GLP-1 drugs ^[4].

What is not known is as important as what is. The largest eloralintide trial to date has 263 participants followed for 48 weeks ^[3], so rare adverse events, long-term safety and cardiovascular outcomes cannot be assessed. No eloralintide label exists. Material bought online adds the further risks of unknown content and no supervision. The FDA’s statement on unapproved GLP-1 drugs used for weight loss does not name eloralintide, but it does say that cagrilintide, the other amylin analogue, cannot be used in compounding under federal law and that products sold as “for research purposes” have been marketed to consumers illegally ^[13].

Eloralintide vs cagrilintide is the comparison that matters, because they are the two long-acting amylin analogues in late development. The pharmacological difference is selectivity: eloralintide preferentially activates the amylin 1 receptor, while cagrilintide also activates the calcitonin receptor ^[1]. They have never been compared in a trial. In separate phase 2 trials, cagrilintide alone produced up to 10.8% weight loss at 26 weeks ^[6] and eloralintide up to 20% at 48 weeks ^[3]; the different durations and populations make that an unfair comparison, and cagrilintide’s development has focused on the CagriSema combination rather than monotherapy ^[7]. Our cagrilintide guide covers CagriSema and the REDEFINE trials.

Against the incretin drugs, eloralintide works through a different receptor, so the interesting question is combination rather than competition. Lilly’s phase 3 trial in people already taking a weekly incretin drug is designed to answer that directly ^[11]. Until then, eloralintide vs tirzepatide or eloralintide vs retatrutide comparisons rest on separate trials: tirzepatide produced 20.9% at 72 weeks in SURMOUNT-1 ^[14] and retatrutide 24.2% at 48 weeks in phase 2 ^[15], against eloralintide’s 20% at 48 weeks in a much smaller study ^[3]. For an overview of the class see peptides for weight loss and our retatrutide vs tirzepatide comparison.

As of September 2026, eloralintide is not approved as a medicine by the FDA, the UK MHRA, the European Medicines Agency, the Australian TGA or any other regulator we could find. It has completed phase 2 and its phase 3 trials are recruiting ^{[8] [9]}, so an approval decision is years away on any normal timeline. There is no eloralintide FDA approval and no filing that we could confirm.

Eloralintide sold as a research product is therefore unlicensed in every country. In the US, the FDA has warned companies selling unapproved weight-loss peptides under research labels ^[13]; see the US legal status page and our report on the FDA warnings to research-use GLP-1 sellers. In the UK, see the UK legal status page; the position in Europe and Australia is the same. Our legal status overview explains how each country treats unlicensed peptides. Taking part in a registered trial is the only route to eloralintide under medical supervision.

No product label exists, so there are no manufacturer storage instructions. Research material is sold as a freeze-dried powder; general practice for peptides of this size is to keep it cold, dry and away from light and to refrigerate it once reconstituted. See how to store peptides. Amylin analogues are prone to clumping into fibrils, which is why natural amylin is hard to use as a drug ^[5]; how research-grade eloralintide behaves once reconstituted has not been published.

PepFinder does not sell eloralintide. If you are comparing research suppliers, see compare eloralintide prices, read how to read a COA, and check our list of third-party tested suppliers. A certificate should report a measured mass consistent with the molecular weight of about 4526 g/mol and state the quantity in the vial, not just purity. Eloralintide was first described publicly in 2025, so any supplier claiming long experience with it should be treated with suspicion.

We track listings in the UK, the US, Canada, Australia and Europe. No published study has tested the content of research-grade eloralintide. Our guides to third-party peptide testing, spotting a fake supplier and peptide prices explained cover what to check.