Brenipatide
A once-monthly dual GIP/GLP-1 receptor agonist from Eli Lilly, in Phase 3 trials for alcohol use disorder and bipolar disorder, with additional studies in obesity, asthma, and smoking cessation.
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 and bipolar disorder, 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, ~1,100 participants) and bipolar disorder, with earlier-stage work in smoking cessation, asthma, obesity, and cardiovascular and liver disease. The evidence base as of early 2026 is entirely unpublished: no Phase 2 or Phase 3 results have been reported, and the mechanistic rationale for addiction and mood applications leans on preclinical work with the related dual agonist tirzepatide showing attenuation of alcohol-induced dopamine signaling in rodents. The central honest caveat is that every claim about brenipatide is currently based on trial design rather than 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, NCT07219953, approximately 1,100 participants) and in bipolar disorder. 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. Earlier-stage trials cover smoking cessation, asthma, cardiovascular and liver disease, and obesity. As of 2026, no efficacy or safety results from any brenipatide 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.
Evidence Snapshot
Human Clinical Evidence
None published. Phase 3 trials are underway for alcohol use disorder (RENEW-ALC-1, ~1,100 participants) and bipolar disorder. Phase 2 trials are running for asthma and smoking withdrawal. Phase 1 trials are active for cardiovascular, liver, and metabolic disorders including obesity. No efficacy or safety data from these trials has been published.
Animal / Preclinical
Indirect. No published preclinical data specific to brenipatide (LY3537031). Mechanistic support comes from studies of the related dual GIP/GLP-1 agonist tirzepatide, which attenuated alcohol-induced dopamine signaling and reduced voluntary alcohol consumption and relapse-like drinking in rodent models.
Mechanistic Rationale
Moderate. The dual GIP/GLP-1 mechanism is well-validated for metabolic indications by tirzepatide's clinical success. The extension to addiction and neuropsychiatric conditions is supported by growing evidence that GLP-1 receptors modulate dopamine reward circuits, though this therapeutic application remains unproven in humans.
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 is 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.
Typical Range
Specific dose ranges for brenipatide have not been disclosed in published clinical trial reports. Phase 3 protocols specify subcutaneous administration; per-dose milligram amounts are presumed to be within the range typical of long-acting peptide incretin development but are not in the public record at this time.
Frequency
Once monthly subcutaneous injection — the defining feature of the molecule's pharmacokinetic profile and the primary engineering rationale for choosing it over weekly competitors.
Timing Considerations
No specific timing requirements: can be administered at any time of day, with or without food, and is not tied to exercise timing. Consistency matters more than the specific clock — dose at roughly the same time each day (or same day each week, for weekly protocols) to keep exposure steady.
Protocol Notes
Because no human dosing data has been published, any specific milligram-per-month figure circulating outside official trial materials should be treated as speculative. Brenipatide is available only through enrollment in active clinical trials. There is no compounding, research-chemical, or off-label channel that legitimately supplies brenipatide at this stage of development. A notable management consideration with once-monthly dosing of any GIP/GLP-1 agonist is that adverse effects — particularly the GI side effects characteristic of the drug class — cannot be quickly reversed by discontinuation in the way they can with shorter-acting agents. Trial protocols presumably address this through dose titration and monitoring; consumer use outside trials would face this risk without a structured safety net.
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
Onset
No onset-of-effect data has been published for brenipatide. Based on the broader GIP/GLP-1 drug class, GI effects typically begin within hours to days of the first dose, while metabolic and (in psychiatric trials) reward-circuit effects would be expected to emerge over weeks of repeated dosing.
Peak Effect
Peak effects for trial endpoints are not yet characterized. By analogy with weekly dual agonists, peak weight and metabolic effects in obesity programs typically take many months of dosing to fully express; behavioral endpoints in addiction and bipolar trials would be expected to follow a similar months-long curve.
After Discontinuation
Once-monthly dosing means circulating drug levels persist for weeks after the last injection. Practical implications include slow offset of both therapeutic effects and adverse effects — patients cannot rapidly clear the drug if they need to discontinue. This is qualitatively different from weekly agents and is one of the open questions for clinical management.
Common Questions
Who Brenipatide Is NOT For
- •Use outside an approved clinical trial — there is no legitimate non-trial supply, and any product marketed as brenipatide outside trial channels should be considered counterfeit or research-chemical of unverified identity.
- •Personal or family history of medullary thyroid carcinoma or MEN 2 syndrome — by analogy with other GLP-1 receptor agonists, which carry a class warning based on rodent thyroid C-cell tumor findings.
- •History of pancreatitis — also a class consideration for GLP-1 receptor agonists pending brenipatide-specific safety data.
- •Pregnancy and breastfeeding — no human reproductive safety data exists; the long half-life amplifies the practical concern about residual drug exposure if pregnancy occurs after dosing.
- •Pediatric use — no studies in pediatric populations.
- •Active eating disorder — applies to incretin-based therapies generally and likely to brenipatide programs in particular.
- •Severe gastroparesis or other significant motility disorders — gastric-emptying delay from incretin agonism may exacerbate these conditions.
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 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
Common Side Effects
Cautions
- • Investigational drug — not FDA-approved for any indication
- • No published efficacy or safety data from clinical trials
- • Not available outside of clinical trial enrollment
What We Don't Know
All safety and efficacy data is currently unpublished. As an investigational drug, the risk profile is undefined. The once-monthly dosing raises questions about management of adverse effects, since the drug cannot be quickly discontinued if side effects occur.
Legal Status
United States
Brenipatide is not FDA-approved for any indication. It is available exclusively through enrollment in active Eli Lilly clinical trials. There is no legitimate commercial, prescription, or compounding-pharmacy supply.
International
No marketing authorization in any major jurisdiction. International access is via approved clinical trial enrollment in countries where studies are running.
Sports & Competition
Brenipatide is not specifically listed on the WADA Prohibited List by name. Its long duration of action and metabolic effects (weight, body composition, appetite) would draw obvious anti-doping attention if used outside an approved indication; WADA's S0 catch-all also covers any substance not approved by any governmental health authority for human therapeutic use, which describes brenipatide at this stage. Athletes subject to anti-doping testing should treat it as off-limits.
Regulatory status changes over time. Verify current local rules with a qualified professional.
Myths & Misconceptions
Myth
Brenipatide is a stronger version of tirzepatide.
Reality
Brenipatide is engineered for longer duration — once-monthly versus weekly — not necessarily for greater per-dose potency at the receptor level. Whether the steady-state effect on metabolic or behavioral endpoints exceeds, matches, or falls short of weekly dual agonists is unknown until trial data is published.
Myth
Brenipatide is available through compounding pharmacies for off-label use.
Reality
Brenipatide is investigational and available only through Eli Lilly clinical trial enrollment. There is no legitimate compounded brenipatide. Anything marketed as brenipatide outside trial channels should be assumed counterfeit or unverified.
Myth
Once-monthly dosing means once-monthly side effects — the rest of the month is drug-free.
Reality
The pharmacokinetic point of monthly dosing is sustained drug presence across the entire month. GI and other class adverse effects can persist throughout the dosing interval, and crucially cannot be rapidly cleared by discontinuation in the way they can with weekly or daily agents.
Myth
Because GLP-1 drugs have helped some people drink less alcohol, brenipatide is essentially proven for alcohol use disorder.
Reality
The reduction in alcohol consumption observed in some patients on weekly GLP-1 agonists is intriguing and is part of the rationale for trials like RENEW-ALC-1, but it is not equivalent to a positive Phase 3 result in a dedicated AUD trial. Brenipatide's clinical efficacy in AUD remains an open question pending those trial readouts.
Myth
Brenipatide is approved for bipolar disorder somewhere in the world.
Reality
Brenipatide has no marketing authorization for bipolar disorder or any other indication in any jurisdiction. The bipolar disorder program is in Phase 3 development and has not produced approval-supporting data.
Published Research
5 studiesTirzepatide attenuates dopamine reward signaling and suppresses alcohol drinking and relapse-like behaviors in rodents.
Can GLP-1 Be a Target for Reward System Related Disorders? A Qualitative Synthesis and Systematic Review.
Mechanisms of GLP-1 in Modulating Craving and Addiction: Neurobiological and Translational Insights.
A Study of Brenipatide in Participants With Moderate-to-Severe Alcohol Use Disorder (RENEW-ALC-1).
RENEW-ALC-1 — Lilly's ~1,100-participant Phase 3 alcohol use disorder trial, the defining brenipatide clinical program and the most-cited source of molecule-specific information while the compound remains pre-publication.
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Quick Facts
- Class
- Incretin Mimetic
- Tier
- F
- Evidence
- Limited
- Safety
- Limited Data
- Updated
- Apr 2026
- Citations
- 5PubMed
Also known as
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Evidence Score
Clinical Trials
View Clinical TrialsLinks to ClinicalTrials.gov for reference. Listing does not imply endorsement.