Eloralintide vs Retatrutide: Amylin Agonist vs Triple Agonist Compared

The two molecules do not share a receptor. Amylin is a hormone co-secreted with insulin from pancreatic beta cells that slows gastric emptying, suppresses glucagon secretion and promotes meal termination through central mechanisms; eloralintide works by selectively activating its receptor, AMY1R. Retatrutide does not touch the amylin pathway at all — it activates the GIP, GLP-1 and glucagon receptors instead, a different hormone family entirely.^[5][10]

Amylin receptors are themselves a composite: the calcitonin receptor paired with a receptor-activity-modifying protein (RAMP), a heterodimeric structure that gave rise to a family of amylin analogues after the first approved agent, pramlintide. Later long-acting entrants took different design paths — cagrilintide is a non-selective dual amylin/calcitonin-receptor agonist, later co-formulated with semaglutide as CagriSema, while amycretin combines amylin-, calcitonin- and GLP-1-receptor activity in one molecule. Eloralintide's discovery work emphasised receptor selectivity instead, aiming for AMY1R activity with comparatively little action elsewhere.^[4]

In the 12-week phase 1 trial, 100 participants with a mean age of 44 and mean BMI of 32.6 received eloralintide or placebo across five dose cohorts without dose escalation. The most common treatment-emergent adverse events were decreased appetite (19%), headache (12%) and fatigue (11%); gastrointestinal events were less frequent, with diarrhoea in 10%, nausea in 8% and vomiting in 4%. At week 12, the least-squares mean reduction in body weight ranged from 2.6% to 11.3% across dose groups, and no deaths occurred.^[2]

The pivotal phase 2 trial, published in The Lancet in December 2025, randomised 263 adults with obesity or overweight and at least one weight-related condition, without diabetes, to weekly eloralintide at 1, 3, 6 or 9 mg, to dose-escalation schedules of 6-9 mg or 3-9 mg, or to placebo, for 48 weeks. Mean body weight change at 48 weeks ranged from -9% at the lowest dose to -20% at 9 mg and at the 6-9 mg escalation, against -0.4% with placebo.^[3]

Tolerability tracked how each dose was reached rather than being uniformly low: nausea was reported by 11-13% of participants at 1 and 3 mg but by 64% at the fixed 6 mg dose, falling to 25% with the slower 3-9 mg escalation; fatigue followed a similar pattern, from 0% at 1 mg to 43-46% at 9 mg and the 6-9 mg escalation. The trial's own reading was that slower dose escalation improved tolerability at a given final dose.^[3]

Retatrutide's own phase 2 obesity trial randomised 338 adults without diabetes to weekly doses of 1-12 mg or placebo for 48 weeks; mean body weight fell by up to 24.2% at the top dose, against 2.1% with placebo. Its first peer-reviewed phase 3 result, in type 2 diabetes, reported weight reductions of up to 15.3% at 40 weeks.^[11][12]

Placing the two phase 2 headline figures side by side, retatrutide's 24.2% against eloralintide's 20%, is tempting and unreliable. The trials differ in mechanism, in how doses were escalated, and in population size (338 versus 263), and were run by different investigator networks; no head-to-head trial between the two exists, and a comparison that ignores those differences is not evidence, it is arithmetic.^[11][3]

The clearer difference is in trial phase. Retatrutide has a published phase 3 result in type 2 diabetes and phase 3 obesity trials registered as completed. Eloralintide has not reached that point: both of its phase 3 trials, ENLIGHTEN-1 (without type 2 diabetes) and ENLIGHTEN-2 (with type 2 diabetes), were recruiting as of September 2026, and their registry entries list primary completion no earlier than January 2028. No phase 3 data for eloralintide has been published.^[12][8][9]

Eloralintide is one of several long-acting amylin-pathway compounds now in development, and cross-trial context helps place it. A 2026 network meta-analysis of six trials (4,642 participants, 12 to 68 weeks) ranked high-dose amycretin as producing the largest placebo-adjusted weight change (-23.95%), followed by high-dose eloralintide (-18.01%) and high-dose CagriSema, a cagrilintide-semaglutide combination (-17.18%); all three outranked semaglutide 2.4 mg (-11.45%) in the same indirect comparison. Gastrointestinal adverse events were more common with the high-dose amylin-pathway agents, and only high-dose CagriSema raised the rate of stopping treatment for adverse events; the review's authors described the underlying evidence as sparse and low-certainty. Cagrilintide and amycretin are separate compounds, not supplied by Peptyds and not detailed further here.^[6]

Across eloralintide's phase 1 and phase 2 trials, the pattern of adverse events differed from the gastrointestinal-dominant profile typical of GLP-1 and multi-agonist peptides: decreased appetite, headache and fatigue were the most common early signals, and gastrointestinal events, while present and dose-related, were not the leading complaint at lower doses. Retatrutide's trials, by contrast, report gastrointestinal effects, mainly nausea, diarrhoea, vomiting and constipation, as the dominant and dose-related adverse events.^[2][3][11]

The two molecules also diverge on heart rate. Retatrutide's phase 2 trial reported a dose-dependent rise in heart rate that peaked at 24 weeks. A 2026 literature review of eloralintide's early clinical studies instead described reductions in pulse rate, alongside lower blood pressure, inflammatory markers and improved lipid parameters — a pattern its authors called potentially distinct from the heart-rate increase associated with GLP-1 receptor agonists. The same review was explicit about the limits of that evidence: it rests on preclinical, phase 1 and phase 2 studies with small samples and short follow-up, and no amylin receptor agonist, eloralintide included, has yet been tested in a dedicated cardiovascular-outcomes trial.^[11][7]

No. Eloralintide is an investigational compound with no marketing authorisation anywhere. As of September 2026, the European Medicines Agency's database of authorised medicines lists no eloralintide product, and no regulatory filing has been made.^[13]

Its development programme is active and broad: alongside the two pivotal phase 3 obesity trials, Lilly has registered phase 3 studies in knee osteoarthritis with obesity and in obstructive sleep apnoea with obesity, plus phase 1 studies in renal and hepatic impairment and in combination with tirzepatide, most recruiting or ongoing as of September 2026. None of these has reported results.^[8][9]

For readers tracking the timeline: ENLIGHTEN-1 and ENLIGHTEN-2 list primary completion dates of March 2028 and January 2028. Retatrutide reached its first published phase 3 result about three years after its phase 2 publication. On a similar timeline, eloralintide's first phase 3 read-out would not be expected before its registered completion dates, and this guide will be updated when one is published.^{[11][12][8][9]}

Peptyds supplies retatrutide as a lyophilised research peptide for in-vitro laboratory work, with the batch documentation described on our quality page. Peptyds does not supply eloralintide. Neither product is a medicine, neither is intended for human or veterinary use, and nothing on this page describes how a person should use either compound.

The evidence records differ in stage. Retatrutide has published phase 1, phase 2 and a first phase 3 trial, with further phase 3 obesity trials registered as completed but without peer-reviewed results at the time of writing, and no EU marketing authorisation. Eloralintide has published phase 1 and phase 2 trials only, two phase 3 trials still recruiting, and no EU or US authorisation. Research interest in both molecules is legitimate; consumer weight-loss claims for either are not supported by either record.^{[11][12][3][8][13]}