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Brenipatide

Brenipatide

Last reviewed October 27, 2026 · 13 sources · Written for general readers · Compare with another compound →

The bottom line

Brenipatide is a real experimental drug from Eli Lilly that works on the same two hormone targets as tirzepatide. Lilly is testing it mainly for alcohol use disorder, depression and other brain conditions, plus asthma, not for weight loss. The only human data so far cover safety in about 200 people, PubMed lists no published studies, and no trial has yet shown that it helps any condition.

Where the evidence stands

What it is

Brenipatide is the official generic name for LY3537031, an experimental peptide drug. FDA's substance registry lists it as a drug that activates both GIP and GLP-1 receptors.[1]

Eli Lilly sponsors the registered trials of brenipatide, and it is given as a shot under the skin.[2] Lilly describes it as a weekly treatment.[3]

Unlike tirzepatide, Lilly is mainly studying brenipatide for brain related conditions such as alcohol use disorder and depression. Its pipeline also lists opioid use, tobacco use, bipolar disorder, schizophrenia and asthma.[3][4]

A search of PubMed in October 2026 found no published research papers on brenipatide or LY3537031.[5]

Name
Brenipatide (Brenipatide)
Other names
LY3537031, LY-3537031
Type
Peptide
CAS number
2408921-49-1

What it does in the body

Brenipatide does not occur in nature. It is a lab made peptide that switches on the receptors for GIP and GLP-1, two hormones the gut releases after eating, the same pair targeted by tirzepatide.[1][6] Lilly says it was built to act on these receptors in the brain.[3]

This is the biology, area by area. A change measured in the body, like a higher blood level, does not always mean a person feels a benefit. The claims check below covers that.

Hormones, appetite and blood sugar

Lab finding

Natural GLP-1 helps regulate appetite and calorie intake, and drugs that switch on both GIP and GLP-1 receptors raise insulin when blood sugar is high, lower glucagon and slow stomach emptying, as described in the tirzepatide label.[6] Brenipatide's own effects on appetite, weight or blood sugar have not been reported.[3]

Brain and reward

Seen in animals

GIP and GLP-1 receptors are found in brain areas that regulate appetite, and in animal studies a drug acting on both reached nerve cells there.[6] Lilly says brenipatide targets reward and addiction pathways, but it has published no brain data for this drug.[3]

Gut

Measured in people

In the first human study of more than 200 people, stomach side effects were reported by 25 percent of people on the drug and 25 percent on placebo.[3][7]

Skin and nerves

Measured in people

About 15 percent of people on the drug reported dysesthesia, meaning unusual or unpleasant skin sensations, versus none on placebo. Why this happens has not been explained.[3]

How long it stays in the body

Measured in people

Blood level testing in the first human study found it lasted about 9 to 12.5 days on average before half was cleared, long enough for once a week shots.[3]

How it works

Brenipatide copies two natural gut hormones, GIP and GLP-1, that help control appetite and blood sugar.[6]

  • It activates both the GIP and GLP-1 receptors, the same pair targeted by tirzepatide.[1][3]
  • Lilly says it is designed to act on these receptors in the brain, including reward and addiction pathways, and on inflammation pathways.[3]
  • In the first human study it stayed in the body for about 9 to 12.5 days on average, which Lilly says suits once a week use.[3]

The brain focused design is Lilly's description. No published data show how much reaches the brain or whether it helps any condition.

What the research shows

We keep animal and human evidence apart. A result in animals is a reason to study something in people, not proof that it works in people.

Animal and lab studies

No published animal studies found

  • We found no peer reviewed animal studies of brenipatide in the public record, and PubMed returned no papers under either of its names.[5]
  • The 2026 conference report on the drug did not describe any animal work.[3]
  • The general finding that drugs acting on both GIP and GLP-1 reach appetite areas of the brain comes from animal studies of tirzepatide, not brenipatide.[6]

Limit: Lilly has not published its lab and animal work on this drug as far as we could find.

Human studies

Early safety data only; big trials still running

  • Phase 1 safety study: Lilly's first human trial began in September 2024 in adults with and without obesity.[2] More than 200 people took part, including a group of Japanese and Chinese participants. Shots were given under the skin with 8 weeks of follow up.[3]
  • Results shared at a psychiatry meeting in September 2026 reported no deaths and no serious side effects. Four people, about 2 percent, stopped because of side effects.[3]
  • Stomach side effects were reported by 25 percent of people on both the drug and placebo.[3]
  • About 15 percent of people on the drug reported dysesthesia, meaning unusual or unpleasant skin sensations, versus none on placebo.[3]
  • The study measured safety and blood levels only. It did not report effects on drinking, mood or weight.[3]
  • Two phase 3 trials in alcohol use disorder, each planning about 1,100 adults for 56 weeks, began in October 2025. Their main measure is change in drinking patterns.[8][9][3]
  • A phase 3 trial in about 1,000 adults with major depression and a phase 2 trial in about 400 adults with bipolar disorder are testing whether it delays relapse.[10][11][4]
  • Lilly's April 2026 pipeline also listed phase 2 trials in opioid use disorder, tobacco use disorder, schizophrenia and asthma, and the earliest listed date for finishing main data collection was February 2027, in the tobacco trial.[4]

Limit: The safety data come from a conference poster reported in the news, not a peer reviewed paper, and no results on benefit exist.

Claims check

The most common claims about this compound, and what studies actually found. Verdicts rate the evidence, not whether you should use it.

Helps people drink less alcohol

Not tested

No results exist yet. Two phase 3 trials, each planning about 1,100 adults with alcohol use disorder, began in October 2025 and run 56 weeks, with main results due around April 2028.[8][9][4] Lilly skipped phase 2 and went straight to these trials.[3]

Treats depression

Not tested

A phase 3 trial in about 1,000 adults with major depression, testing whether it delays relapse when added to usual care, began in 2026 and has not reported results.[10][3] Its main results are expected around February 2028.[4]

Causes weight loss like tirzepatide

Not tested

The only human study so far, in adults with and without obesity, reported safety and blood levels but no weight results.[3][2] Lilly is not developing it mainly as a weight loss drug, though a phase 2 trial in schizophrenia uses weight change as its main measure.[3][4]

Helps with smoking, opioids and other addictions

Not tested

Lilly lists phase 2 trials in tobacco use disorder (about 222 people) and opioid use disorder (about 465 people), along with bipolar disorder and schizophrenia, but none has reported results.[4][11] The tobacco study looks at preventing relapse, and the opioid study tests it alongside other medicines.[7] A Lilly scientist pointed only to informal patient stories from other drugs in this class, not to data on brenipatide.[7]

Easier on the stomach than other GLP-1 drugs

Mixed results

In the first human study of more than 200 people, stomach side effects were reported by 25 percent of people on the drug and 25 percent on placebo.[3][7] That is one small, early study with no head to head comparison against other drugs, and about 15 percent on the drug reported unusual skin sensations.[3]

Known risks and side effects

  • Unknown effectiveness. None of the trials have reported results on benefit. Most are expected to finish between 2027 and 2028.[4][8][10]
  • Unusual skin sensations. Early data showed odd skin sensations in about 15 percent of people on the drug and none on placebo.[3]
  • Stomach side effects. A quarter of people in the first study reported stomach side effects, though the same share did on placebo.[3]
  • Not available outside trials. The only legitimate source is Lilly's clinical trials. FDA warns that drugs in this class sold online as research use only have unknown quality.[12]
  • Banned in sport. As an unapproved drug, it likely falls under WADA's S0 class, which bans unapproved substances at all times.[13]

Regulatory status

Today: Brenipatide is not approved anywhere. It is an investigational drug in active phase 2 and phase 3 trials sponsored by Eli Lilly.[8][10][11][4]

  1. Phase 1 safety trial of LY3537031 begins.[2]
  2. Two phase 3 trials in alcohol use disorder begin.[8][9]
  3. Phase 2 trial in bipolar disorder begins.[11]
  4. Phase 3 trial in major depression begins.[10]
  5. Lilly's pipeline lists eight brenipatide trials, including asthma and schizophrenia.[4]
  6. Early phase 1 safety data presented at a psychiatry meeting.[3]

Sources

  1. U.S. Food and Drug Administration. Global Substance Registration System: Brenipatide. UNII C3939LZT6J. UNII C3939LZT6J
  2. ClinicalTrials.gov. A Study of LY3537031 in Overweight, Obese, and Healthy Participants. NCT06606106. NCT06606106
  3. GEN Genetic Engineering & Biotechnology News. Lilly's GIP/GLP-1 candidate brenipatide shows early clinical promise in substance, psych disorders. September 19, 2026. News report
  4. Eli Lilly and Company. Q1 2026 earnings call presentation, including pipeline and registered trials as of April 20, 2026. April 28, 2026. Company presentation
  5. National Library of Medicine. PubMed search: brenipatide OR LY3537031 (no results). Searched October 2026. PubMed search
  6. Eli Lilly and Company. ZEPBOUND (tirzepatide) injection: prescribing information. Revised 02/2026. FDA label
  7. Psychiatric Times. Early brenipatide data shows substance use treatment potential. September 18, 2026. News report
  8. ClinicalTrials.gov. A Study of Brenipatide in Participants With Moderate-to-Severe Alcohol Use Disorder (RENEW-ALC-1). NCT07219966. NCT07219966
  9. ClinicalTrials.gov. A Study of Brenipatide in Participants With Alcohol Use Disorder (RENEW-ALC-2). NCT07219953. NCT07219953
  10. ClinicalTrials.gov. A Study of Brenipatide in Adult Participants With Major Depressive Disorder (RENEW-MDD-1). NCT07412756. NCT07412756
  11. ClinicalTrials.gov. A Study of Brenipatide in Adult Participants With Bipolar Disorder (RENEW-Bipolar-1). NCT07286175. NCT07286175
  12. U.S. Food and Drug Administration. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Content current as of October 1, 2026. FDA safety page
  13. World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. Effective January 1, 2026. WADA 2026 Prohibited List
Medical disclaimer

This page is educational information only. It is not medical advice and does not replace care from a licensed medical provider. Do not use this page to decide whether to take any substance. Talk to a licensed medical provider first.

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