Weight & Metabolic
Eloralintide
aka LY3841136 · LY-3841136 · elora · eloral · eloralintide peptide · lilly amylin · eloralinitide · eloralintid · eloralentide
Grade
An experimental once-weekly amylin injection from Eli Lilly that produced large weight loss in one mid-stage trial. It is still in Phase 3 testing, not an approved medicine, yet it is already sold online as a 'research peptide'.
- Class
- Long-acting amylin analogue (selective amylin receptor agonist); injectable peptide
- Evidence
- Grade B · Promising human evidence
- Sport / WADA
- Prohibited at all times under S0 (non-approved substances). The WADA 2026 Prohibited List bans any substance with no current approval by a regulatory health authority for human therapeutic use, explicitly including drugs in clinical development.
- Last reviewed
- 2026-10
Grade B · Promising human evidence
Why this grade
Real, published, placebo-controlled human trials, but at the lower end of B. The main evidence is a single 48-week Phase 2 trial in 263 US adults (Lancet 2025) showing dose-dependent weight loss of up to about 20% versus 0.4% on placebo, plus small Phase 1 studies. That figure used the efficacy estimand (people who stayed on treatment), the trial was 78% female, and all studies were run by the manufacturer, Eli Lilly. Phase 3 trials (the ENLIGHTEN programme) started in late 2025 and 2026 and have not reported. No regulator has approved it.
What is it?
Why people buy it
People buy it to lose weight. It is a new weekly injection that makes you feel full.
What we actually know
- •It copies amylin, a natural hormone that tells your body it is full.
- •One study followed 263 people for almost a year. On the higher doses, people lost about 16 to 20% of their weight.
- •That study counted people who kept taking it. People on a dummy treatment lost almost nothing.
- •It is still being tested in large studies. It is not a licensed medicine in the UK or anywhere else.
What might happen
- •Weight loss looks likely, going by that one study. Bigger studies have not finished yet.
- •Feeling sick was common at higher doses. Many people also felt very tired.
- •Long-term safety is unknown.
- •It is sold online as 'not for human use'. Nobody checks what is really in the bottle.
- •It is banned in sport at all times, because it is not an approved medicine.
Bottom line
Promising early results in people, but only from one mid-size study. The online versions are not the tested product.
Know someone taking this?
Send on WhatsAppEloralintide is like a promising new player who had one brilliant season in the second division. The stats are real and published, but they come from one season, with the club's own scouts keeping score. The top-flight season (Phase 3) has only just kicked off. The shirts with its name on, sold outside the ground, are not the player.
How is it meant to work?
A long-acting man-made analogue of the satiety hormone amylin. It activates amylin receptors, preferring the AMY1 receptor subtype, in brain areas that control appetite, increasing fullness, slowing gastric emptying and reducing food intake. This acts on a different appetite system from GLP-1 drugs such as semaglutide and tirzepatide. Given by once-weekly subcutaneous injection in trials.
What's it studied for?
Research contexts. Not proven uses, and not recommendations.
Does the human evidence stack up?
Promising but thin. One published 48-week Phase 2 trial (Lancet 2025, n=263) showed dose-dependent weight loss from about 9% at the lowest dose to about 20% at the higher doses, versus 0.4% on placebo, using the efficacy estimand (on-treatment). Two Phase 1 studies (48 healthy volunteers; 100 people with obesity or overweight over 12 weeks) support weekly dosing and showed early weight loss. All trials were sponsored by Eli Lilly, the Phase 2 population was mostly female and entirely US-based, and the larger Phase 3 ENLIGHTEN trials have not reported. There are no long-term safety data.
What could go wrong?
- !Not licensed by the MHRA or any other regulator. Its benefit-risk balance has not been signed off for any use
- !Nausea and fatigue were common in the Phase 2 trial at some doses (nausea up to 64%, fatigue up to 46%, versus 14% and 12% on placebo)
- !Evidence rests on one mid-size Phase 2 trial plus small Phase 1 studies, all run by the manufacturer; Phase 3 results are not yet available
- !The headline Phase 2 weight-loss figures use the efficacy estimand (people who stayed on treatment), which gives higher numbers than counting everyone who started
- !No long-term safety data
- !GREY MARKET: 'eloralintide' is already listed by online 'research peptide' sellers, including UK-facing ones, as not for human consumption. Identity, dose, purity and sterility are unverified and it is not the trial product
Is it legal in the UK?
Investigational drug, not a licensed UK medicine. The MHRA has not granted a marketing authorisation, and it is not available on prescription or the NHS. Legitimate access is only through a registered clinical trial. Products sold online as 'eloralintide' are unlicensed research chemicals marketed 'not for human consumption'; supplying it for human use would breach the Human Medicines Regulations 2012.
Key trials
- NCT06230523· Phase 2· Completed
A Study of LY3841136 Compared With Placebo in Adult Participants With Obesity or Overweight
263 participants, 48 weeks; published in The Lancet 2025.
- NCT07321886· Phase 3· Recruiting
ENLIGHTEN-1: Eloralintide in obesity or overweight without type 2 diabetes
About 1,980 participants planned; started February 2026.
- NCT07282600· Phase 3· Recruiting
ENLIGHTEN-2: Eloralintide in obesity or overweight with type 2 diabetes
About 1,035 participants planned; started December 2025.
Sources
- 01Eloralintide, a selective amylin receptor agonist for the treatment of obesity: a 48-week phase 2, multicentre, double-blind, randomised, placebo-controlled trial — Billings LK, et al., The Lancet (2025)
n=263; up to about 20% mean weight loss at 48 weeks vs 0.4% placebo (efficacy estimand); nausea and fatigue most common.
- 02Eloralintide (LY3841136), a novel amylin receptor agonist for the treatment of obesity: From discovery to clinical proof of concept — Briere DA, et al., Molecular Metabolism (2025)
Receptor selectivity (AMY1R), rat and monkey data, and single-dose Phase 1 in 48 healthy volunteers.
- 03Eloralintide, a selective, long-acting amylin receptor agonist for treatment of obesity: Phase 1 proof of concept — Bhattachar S, et al., Diabetes, Obesity and Metabolism (2026)
12-week multiple-ascending-dose study in 100 people; 2.6% to 11.3% weight loss across dose groups.
- 04ENLIGHTEN-1: A Study of Eloralintide (LY3841136) in Participants With Obesity, or Overweight Without Type 2 Diabetes, ClinicalTrials.gov (2026)
Phase 3, recruiting; started February 2026.
- 05World Anti-Doping Code International Standard: Prohibited List 2026, World Anti-Doping Agency (2026)
S0 non-approved substances: drugs under clinical development are prohibited at all times.
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Before you trust a vial
Peptides are freeze-dried for a reason. If you have seen Eloralintide sold pre-mixed in a ready-to-use pen or syringe, here is why that is a red flag for potency, sterility and dosing.
Storage & stability →Stay posted
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