Eloralintide

What it is

Amylin is a hormone that the pancreas releases together with insulin. It slows gastric emptying, curbs glucagon and signals to the brainstem that the meal is over. It is thus a second satiety system alongside GLP-1, the principle behind semaglutide.

Eloralintide, development name LY3841136, is an artificially stabilized amylin analogue: a chain of 37 amino acids with three non-natural building blocks at positions 11, 15 and 22, whose sulfur bridge has been replaced by a chemically more stable bridge. At position 26 there is a fatty diacid with 20 carbon atoms that binds the molecule to albumin in the blood and thereby keeps it active for a long time. The half-life is about 2 weeks; one injection per week is sufficient.

The real difference from its predecessors lies in the choice of receptor. Eloralintide activates the human amylin 1 receptor 12-fold more strongly than the calcitonin receptor and 11-fold more strongly than the amylin 3 receptor, whereas cagrilintide hits all of these receptors. The idea: if nausea and satiety run via different circuits, a more targeted drug could deliver the same effect with fewer side effects.

What the studies in humans show

The key paper is a phase 2 trial published in the Lancet. 263 adults with obesity or with overweight plus a weight-related comorbidity, but without type 2 diabetes, were allocated at 46 centers in the US to six active-drug groups and placebo and treated once a week for 48 weeks. Mean baseline weight was 109.1 kilograms, body mass index 39.1; a good three quarters of the participants were women.

All active-drug groups reached the primary endpoint. Weight loss after 48 weeks was 9 percent in the lowest and 20 percent in the two highest groups, under placebo 0.4 percent. For the same trial, the manufacturer reports 9.5 to 20.1 percent using a different estimand, or 10.2 to 21.3 in kilograms. A review gives 7.3 to 17.5 percent compared with 2.3 percent under placebo for the same data set. Which figure one cites therefore depends on which analysis is meant.

Before that came two phase 1 studies. Even a single injection lowered weight in 48 healthy participants by 2.5 and 4.4 percent at week 4, while the placebo group gained 0.6 percent. Over 12 weeks of repeated administration, 100 participants reached 2.6 to 11.3 percent – deliberately without any dose escalation.

The pulse goes down

One finding falls outside what is known from weight-loss injections. In the 12-week study, heart rate fell by 14.4 beats per minute under the highest dose, and by 3.4 under placebo. Symptomatic bradycardia, that is, an excessively slow heartbeat with symptoms, did not occur.

A 2026 cardiology review highlights exactly this: under GLP-1 receptor agonists, heart rate usually rises; here it falls. Together with the predominant loss of fat mass and favorable values for inflammatory and blood lipid markers, this results in a distinct profile. The authors remain sober: the data come from early, small studies, and there is no outcome trial on heart attacks and strokes for any amylin drug.

Where it stands in the race

A 2026 network meta-analysis placed 6 randomized trials with 4,642 participants side by side. High-dose eloralintide reached minus 18.01 percent versus placebo and came in second, behind high-dose amycretin at minus 23.95 and ahead of CagriSema at minus 17.18 percent. Semaglutide 2.4 milligrams was at minus 11.45, liraglutide 3.0 milligrams at minus 6.4 percent. These are indirect comparisons; the authors rate their certainty as low.

Development is nonetheless advanced: five phase 3 trials of the ENLIGHTEN program are recruiting, the first in type 2 diabetes since December 2025, the large obesity trial with 1,980 planned participants since February 2026, plus trials in sleep apnea, in knee osteoarthritis and in people who no longer lose weight on weekly incretin therapy. In parallel, combination trials are running with tirzepatide and with the Lilly candidate macupatide. For the combination with tirzepatide, called EloraTZP, Lilly reported results on September 30, 2026 from a 48-week phase 2b trial with 367 adults with overweight or obesity and type 2 diabetes: at the highest dose they lost 23.3 percent, under tirzepatide 15 milligrams alone 14.8 percent, under placebo 3.0 percent. On the other hand, 10.8 to 27.0 percent discontinued treatment under the combination, 2.9 percent under tirzepatide alone. These are manufacturer figures, presented at the European diabetes congress, not yet published in peer-reviewed form. The amylin axis is therefore not conceived as competition to GLP-1 but as a complement.

What the studies show

48 weeks, 263 participants (Billings, Lancet 2025)

Randomized, double-blind, placebo-controlled, 46 centers in the US. Adults aged 18 to 75 with a body mass index of 30 or more, or 27 or more plus at least one weight-related comorbidity, without type 2 diabetes, were included. Six active-drug groups, two of them with gradual dose escalation, and a placebo group with 53 participants. After 48 weeks, weight loss was between 9 and 20 percent, under placebo 0.4 percent. The most common adverse events were nausea and fatigue.

12 weeks without dose escalation (Bhattachar, Diabetes Obes Metab 2026)

In this phase 1b study, 100 participants with overweight or obesity at 3 US centers received a fixed dose weekly for 12 weeks, deliberately without dose escalation. Weight loss at week 12 ranged from 2.6 to 11.3 percent; the placebo group gained 0.2 percent. Gastrointestinal events were rare: diarrhea in 10, nausea in 8 and vomiting in 4 percent. More frequent were decreased appetite at 19 percent and headache at 12 percent.

From the molecule to the first human (Briere, Mol Metab 2025)

This paper describes structure, cell experiments, animal studies and the first-in-human study in one. In cell systems, the 12-fold selectivity for the amylin 1 receptor was shown; in obese rats, weight fell by 12.3 percent by day 13, with 68 to 85 percent of the loss attributable to fat mass. In the phase 1 study in 48 healthy participants, 16 adverse events occurred in 9 participants, 15 of them mild.

Where the data stop

The hope that a more targeted drug would make slow dose escalation unnecessary was not confirmed in phase 2. In the 6-milligram group without dose escalation, 64 percent reported nausea; in the 9-milligram group only 33 percent, because the dose was increased gradually there. Fatigue occurred in up to 46 percent of cases, under placebo in 12 percent. About 10 percent of participants stopped treatment because of adverse events; according to another analysis, up to 21 percent in the 6-milligram group.

In addition, everything that only phase 3 can deliver is missing: results over more than 48 weeks, larger and more broadly composed groups, a direct comparison with semaglutide or tirzepatide, and a cardiovascular outcome trial. There are also no figures on the share of muscle mass in the weight loss in humans – the fat mass shares of 68 to 85 percent come from the rat experiment. The mood-related events in 4 participants of the phase 1b study are too rare for an assessment, but in the highest dose group they were a reason for treatment discontinuations.

Status, approval and legal

Eloralintide is an investigational drug from Eli Lilly and is not approved in Germany, the EU or the US. It is not available outside clinical trials. The ENLIGHTEN phase 3 program is underway: the trial in type 2 diabetes since December 2025, the large obesity trial with 1,980 planned participants since February 2026, plus trials in obstructive sleep apnea, in knee osteoarthritis and in persistent obesity under incretin therapy. Approval is therefore not to be expected before the end of the decade. Anyone seeking drug-based help with weight loss today should discuss the approved drugs with their doctor. What is offered online under this name is not the tested molecule. We do not state dosages for unapproved substances; the milligram amounts mentioned are study doses.

Safety

The most common adverse events were nausea and fatigue, both clearly dose-dependent and less frequent in the groups with gradual dose escalation. Serious incidents did not occur: in the phase 2 trial there was no pancreatitis, no cholecystitis and no deaths. In the phase 1b study there were two serious events, both of which the investigator classified as not treatment-related. Injection site reactions were more frequent than under placebo, mostly mild. The pulse drops markedly; people with heart disease or an abnormal heart rate were excluded from this study, so there are no data for them. Data are also lacking for pregnancy, breastfeeding, children and adolescents; studies on kidney and liver function are only just underway. As with any substantial weight loss, sufficient protein, strength training and medical supervision are part of it.

Sources

• Billings LK et al., Lancet 2025 – phase 2 trial over 48 weeks
• Bhattachar S et al., Diabetes Obes Metab 2026 – phase 1b over 12 weeks
• Briere DA et al., Mol Metab 2025 – molecule, animal studies, first-in-human study
• Kamrul-Hasan ABM et al., Endocrinol Diabetes Metab 2026 – network meta-analysis of amylin therapies
• Alhazmi A, le Roux CW, Diabetes Obes Metab 2026 – review of amylin analogues
• Patil M et al., Biosci Rep 2026 – review with phase 2 discontinuation rates
• Sigalov A, Frishman WH, Cardiol Rev 2026 – cardiometabolic profile and heart rate
• Bassatne A, Rizo I, Adv Ther 2026 – review with differing efficacy figures
• ClinicalTrials.gov – ENLIGHTEN-1 (NCT07321886), phase 3 in obesity
• Eli Lilly, company announcement on phase 2, November 6, 2025
• Eli Lilly, company announcement on EloraTZP (eloralintide plus tirzepatide), phase 2b, September 30, 2026