Brenipatide

What is Brenipatide?

Brenipatide (LY3537031) is a dual GIP/GLP-1 receptor agonist under development by Eli Lilly. It belongs to the same drug class as tirzepatide (Mounjaro/Zepbound) but is engineered with a longer half-life that enables once-monthly subcutaneous dosing — compared to weekly injections for tirzepatide, semaglutide, and retatrutide. A key structural modification (Trp to alpha-methyl-tyrosine substitution) enhances its resistance to enzymatic degradation. What makes brenipatide unusual among incretin mimetics is its primary development focus: rather than leading with obesity or diabetes, Lilly is running Phase 3 trials in alcohol use disorder (RENEW-ALC-1 and RENEW-ALC-2) and major depressive disorder (RENEW-MDD-1 and RENEW-MDD-2), with bipolar disorder, schizophrenia and opioid use disorder in Phase 2, targeting the dopamine reward pathways that GIP/GLP-1 signaling modulates.

What Brenipatide Is Investigated For

Brenipatide (LY3537031) is an Eli Lilly dual GIP/GLP-1 agonist engineered for once-monthly dosing, with a distinctive development strategy that leads with neuropsychiatric indications rather than obesity or diabetes — Phase 3 trials are running in alcohol use disorder (RENEW-ALC-1 and RENEW-ALC-2, ~1,100 participants each) and major depressive disorder (RENEW-MDD-1 and RENEW-MDD-2, ~1,000 each), with Phase 2 work in bipolar disorder, schizophrenia, opioid use disorder, smoking cessation, asthma, COPD and irritable bowel syndrome, and earlier-stage work in obesity, and cardiovascular and liver disease. The evidence base as of September 2026 is entirely unpublished for brenipatide specifically, but the class scaffolding has firmed up substantially over the summer: Leggio's J Clin Invest overview of GLP-1-targeted therapies for alcohol and other substance use disorders (Sep 2026, PMID 42677833), a Curr Psychiatry Rep review of GLP-1 and dual GIP/GLP-1 psychopharmacology (Schifano et al., Aug 2026, PMID 42624955), a Biol Psychiatry preclinical synthesis of GLP-1 and alcohol-related behaviors (Jerlhag, Oct 2026, PMID 42461204), an Am J Psychiatry editorial framing GLP-1 receptor agonists as potential AUD treatments (Kranzler and Hartwell, Sep 2026, PMID 42675560), and a Biol Psychiatry Glob Open Sci review specifically on the GIP/GLP-1 dual agonist class in AUD and comorbidities (Reitz et al., Nov 2026, PMID 42741173) all landed in the summer 2026 window. The central honest caveat is that every claim about brenipatide is currently based on trial design and adjacent class rationale rather than brenipatide-specific trial data. The once-monthly dosing is pharmacologically novel but also raises a specific management concern — adverse effects cannot be quickly reversed by discontinuation the way they can with weekly incretin agents. The compound is investigational, not FDA-approved, and not available outside active Lilly trial enrollment.

History & Discovery

Brenipatide (LY3537031) is one of Eli Lilly's next-generation incretin candidates, emerging from the same metabolic-peptide research program that produced tirzepatide (the GIP/GLP-1 dual agonist marketed as Mounjaro and Zepbound) and retatrutide (the triple GIP/GLP-1/glucagon agonist in advanced development for obesity). Where tirzepatide demonstrated commercial and clinical success of dual incretin agonism with weekly dosing, brenipatide was engineered for substantially extended duration — a structural backbone modification (notably the substitution of an alpha-methyl-tyrosine for a tryptophan residue) confers resistance to enzymatic degradation and produces a half-life suitable for once-monthly subcutaneous administration. What distinguishes brenipatide from the rest of the Lilly incretin pipeline is the lead clinical strategy. Rather than positioning the drug primarily for obesity or type 2 diabetes — categories that are increasingly crowded with weekly options — Lilly's most prominent Phase 3 program for brenipatide is in alcohol use disorder (RENEW-ALC-1, NCT07219966, and RENEW-ALC-2, NCT07219953, approximately 1,100 participants each, both started October 2025), followed by Phase 3 trials in major depressive disorder (RENEW-MDD-1 from February 2026 and RENEW-MDD-2 from August 2026) and a Phase 2 relapse-prevention trial in bipolar disorder (RENEW-Bipolar-1, NCT07286175). This reflects a growing translational interest in GLP-1 and dual GIP/GLP-1 effects on central reward circuitry, supported by preclinical work showing tirzepatide attenuates alcohol-induced dopamine signaling and reduces voluntary alcohol consumption in rodent models. Through summer and early fall 2026, a wave of high-tier peer-reviewed reviews consolidated the class case that the RENEW-ALC trials are testing. Leggio's J Clin Invest paper 'GLP-1-targeted therapies for alcohol and other substance use disorders' (September 1, 2026, PMID 42677833) surveyed the preclinical and early-clinical GLP-1-in-addiction evidence from the field's most-cited investigator. Kranzler and Hartwell's Am J Psychiatry editorial (September 2026, PMID 42675560) framed GLP-1 receptor agonists as potential AUD treatments from the psychiatric-treatment perspective. Schifano and colleagues (Curr Psychiatry Rep, August 21, 2026, PMID 42624955) reviewed the psychopharmacology of GLP-1 and dual GIP/GLP-1 agonists. Jerlhag (Biol Psychiatry, October 2026, PMID 42461204) synthesised the preclinical alcohol-behavior mechanistic literature. Reitz et al. (Biol Psychiatry Glob Open Sci, November 2026, PMID 42741173) covered the GIP/GLP-1 dual-agonist class specifically in AUD and neuropsychiatric comorbidities — the review closest to a brenipatide-framing paper. Earlier-stage brenipatide trials cover smoking relapse prevention, schizophrenia, opioid use disorder, asthma, COPD, irritable bowel syndrome, cardiovascular and liver disease, and obesity. As of September 2026, no efficacy or safety results from any brenipatide-specific trial have been published, and the drug is not commercially available.

How It Works

Brenipatide activates the same two hormone receptors as tirzepatide (GIP and GLP-1), but with a much longer duration of action — lasting a month instead of a week. Beyond the metabolic effects on blood sugar and appetite, it also modulates dopamine reward signaling in the brain, which is why Lilly is studying it for addiction and psychiatric conditions.

Brenipatide is a dual agonist of the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. Like tirzepatide, it enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite. Its distinguishing feature is a structural modification (Trp to alpha-methyl-tyrosine substitution) that confers resistance to enzymatic degradation, producing a half-life longer than tirzepatide or retatrutide and enabling once-monthly dosing. Beyond metabolic effects, GLP-1 receptor activation dampens reward signaling through alpha-MSH-driven GABAergic inhibition of the paraventricular nucleus to ventral tegmental area pathway and direct modulation of VTA dopaminergic neurons. GIP receptor activation promotes PI3K/AKT/mTOR-mediated synaptic plasticity, potentially enhancing top-down control over reward-seeking behavior. Preclinical data with the related dual agonist tirzepatide demonstrated attenuation of alcohol-induced dopamine signaling and dose-dependent reduction in voluntary alcohol consumption. Jerlhag's Biol Psychiatry synthesis of the preclinical GLP-1/alcohol literature (October 2026, PMID 42461204) laid out the mesolimbic-dopaminergic, stress-axis, and appetitive-behavior mechanisms in detail, and Reitz et al. (Biol Psychiatry Glob Open Sci November 2026, PMID 42741173) covered the specific GIP/GLP-1 dual-agonist pharmacology relevant to brenipatide's class.

Evidence Snapshot

Research Gaps & Open Questions

What the current literature has not yet settled about Brenipatide:

• 01All efficacy and safety data — no clinical trial results have been published for brenipatide in any indication.
• 02Dose-response — trial protocols have not been disclosed in detail; the optimal monthly dose for each studied indication is unknown.
• 03Long-term safety with monthly dosing — the GIP/GLP-1 class has accumulating long-term safety data with weekly agents, but a monthly agent is a different exposure profile, particularly around managing adverse events and pregnancy planning.
• 04Translation of animal addiction data to humans — preclinical work with tirzepatide on alcohol-related dopamine signaling is suggestive but not predictive; whether brenipatide translates to clinically meaningful reductions in heavy drinking days, abstinence, or relapse is exactly what RENEW-ALC-1 and RENEW-ALC-2 are meant to test.
• 05Bipolar disorder mechanism — the clinical rationale for incretin therapy in bipolar disorder is less well established than in addiction, and the mechanistic basis for any benefit (mood, metabolic comorbidity, or both) will need careful characterization.
• 06Comparison to weekly dual agonists — there are no head-to-head trials versus tirzepatide or other incretin agents, so the relative balance of monthly convenience versus less granular dose adjustment is unstudied.

Forms & Administration

Brenipatide is administered via subcutaneous injection once monthly. It is currently only available through clinical trial enrollment and is not commercially available. All investigational peptides should only be used within the context of approved clinical trials.

Dosing & Protocols

The ranges below reflect protocols commonly discussed in the literature and by clinicians — not a prescription. Actual dosing for any individual should be determined by a qualified healthcare provider who knows the patient.

Brenipatide is investigational. It is not FDA-approved for any indication and is not commercially available. The dosing description here reflects published trial design parameters, not consumer dosing guidance.

Timeline of Effects

Common Questions

Who Brenipatide Is NOT For

Drug & Supplement Interactions

No clinical drug-interaction data has been published for brenipatide. The following are theoretical and inferred from the broader GIP/GLP-1 receptor agonist class. The most clinically important class-level interaction is with insulin and insulin secretagogues (sulfonylureas, meglitinides) in patients with diabetes — additive hypoglycemia risk that typically requires dose reduction of the background hypoglycemic agent. Brenipatide trials in psychiatric populations would presumably screen for and manage diabetes carefully given this concern. Delayed gastric emptying — a defining pharmacodynamic feature of GLP-1 and dual GIP/GLP-1 agonists — can alter the absorption of orally administered medications, particularly those with narrow therapeutic indices, time-sensitive absorption, or modified-release formulations. Once-monthly dosing means this effect persists chronically. In the addiction, depression and bipolar populations brenipatide is being studied in, polypharmacy is common (mood stabilizers, antipsychotics, anticonvulsants, anti-craving agents, and others). Specific brenipatide interaction data with these classes will need to come from the trial program itself; until then, prescribing in those populations should not be assumed safe outside a trial. Alcohol consumption itself is the explicit subject of the AUD program and is presumably permitted in trial protocols; how alcohol intake interacts with brenipatide pharmacokinetics and adverse-effect profile is part of what those trials will characterize.

Safety Profile

Legal Status

Regulatory status changes over time. Verify current local rules with a qualified professional.

Myths & Misconceptions