What Is Eloralintide? Lilly's Amylin Weight-Loss Drug Explained

Eloralintide (code name LY3841136) is Eli Lilly's investigational once-weekly amylin drug for obesity. It works on a different hormone pathway from Zepbound or Wegovy. In a 48-week phase 2 trial published in The Lancet, people on the higher doses lost about 20% of their body weight, against 0.4% on placebo.^[1] That is in the range of tirzepatide, from a drug that isn't a GLP-1 at all. Phase 3 trials began in late 2025 and early 2026.^[4] Here is what eloralintide is, what the trials showed, the side effects, and when it might be available.

The short answer

• What it is: a long-acting, selective amylin receptor agonist, injected once a week.^[1][3]
• How well it works: −18% to −20% body weight at 48 weeks on 6–9 mg in phase 2, against −0.4% on placebo.^[1]
• Main side effects: nausea and fatigue. Fatigue affected up to 43–46% on the higher doses, against 12% on placebo.^[1]
• Status: in phase 3 for obesity, type 2 diabetes, sleep apnea and knee osteoarthritis, and in people already taking a weekly incretin drug. Not approved.^[4]

What is amylin, and how is eloralintide different?

Amylin is a hormone released with insulin after meals. It slows stomach emptying and signals fullness to the brain through a different route from GLP-1. Several drug companies are developing amylin drugs, alone or combined with GLP-1 drugs. See our explainers on cagrilintide, petrelintide and amycretin (zenagamtide).

Eloralintide's distinguishing feature is selectivity. In lab tests it “preferentially activated human AMY1R” (amylin receptor type 1), about 12-fold more than the related calcitonin receptor. In rats it caused “significantly less conditioned taste avoidance” than cagrilintide, a non-selective amylin drug. That is a lab marker for nausea-like aversion.^[3] Whether this translates into fewer side effects in people is still being tested.

The phase 2 trial (Lancet, 2025)

The phase 2 trial randomly assigned 263 adults with obesity or overweight (mean BMI 39.1, mean weight 109 kg, 78% women) to one of six eloralintide regimens or placebo for 48 weeks.^[1]

Weight loss rose with dose up to about 20%. Nausea was common at 6 mg (64%), and fatigue was notably frequent at the higher doses: 43% on 9 mg and 46% on the 6→9 mg regimen, against 12% on placebo.^[1] Starting at a lower dose (3→9 mg) gave less nausea and fatigue, with somewhat less weight loss (−16%). The trial used the efficacy estimand, which estimates the effect for people who stay on the drug as assigned.

Earlier phase 1 results

In a 12-week phase 1 study of 100 people with obesity or overweight, eloralintide was given without dose escalation. Weight fell 2.6% to 11.3% across doses. The most common side effects were decreased appetite (19%), headache (12%) and fatigue (11%), while nausea (8%) and vomiting (4%) were “infrequent.”^[2]

How it compares

No trial has compared eloralintide head to head with an approved drug, and its trial lasted 48 weeks, shorter than the 68–72 weeks of the main Wegovy and Zepbound trials. With that caveat, about 20% at 48 weeks puts it in the same range as tirzepatide's 20.9% at 72 weeks in SURMOUNT-1.^[5] Combinations are also being explored: a completed phase 1 study tested eloralintide together with tirzepatide, and one phase 3 trial adds eloralintide for people whose obesity persists on a weekly incretin drug.^[4] For the wider pipeline, see our GLP-1 pipeline tracker.

Phase 3 trials and timeline

ClinicalTrials.gov lists several Lilly phase 3 trials of eloralintide that started recruiting between December 2025 and February 2026:^[4]

• Obesity or overweight without type 2 diabetes (NCT07321886)
• Obesity or overweight with type 2 diabetes (NCT07282600)
• Obstructive sleep apnea with obesity (NCT07369011)
• Knee osteoarthritis pain with obesity (NCT07353931)
• Persistent obesity in people already on a weekly incretin drug (NCT07392190)

Lilly has not announced a filing date, and none of these trials has reported results yet. Until it is approved, eloralintide cannot be prescribed by telehealth providers or made by compounding pharmacies.

Bottom line

Eloralintide produced weight loss approaching 20% in a 48-week trial without acting on the GLP-1 receptor, which makes it one of the most closely watched new obesity drugs. Its distinct side-effect profile, with frequent fatigue at high doses, and its phase 3 results will decide whether it becomes a standalone option, an add-on to incretin drugs, or both. For now it exists only inside clinical trials.