Peptide research is extending beyond weight management, with scientists investigating potential treatments for alcohol use disorder and mental health conditions. Dr Susan Burger examines brenipatide, Eli Lilly’s investigational monthly peptide, explaining how it works, who could potentially benefit and what remains unknown. She also considers the path towards possible approval and cautions against buying unapproved and fake peptides marketed online.
If you follow the world of peptides, you have probably seen the name brenipatide appear in the same breath as semaglutide, tirzepatide and retatrutide. It is being described as “the next one”. Some of that is true. A good deal of it is not. Here is what we actually know as of October 2026, and what you should do if someone offers to sell it to you.
What it is
Brenipatide (development code LY3537031) is an investigational peptide made by Eli Lilly, the company behind Mounjaro and Zepbound. Like tirzepatide, it activates two of the body’s gut-hormone receptors at once: GLP-1 and GIP. These are the same signals that tell your brain you have eaten, slow the stomach down and help the pancreas manage blood sugar.
The engineering difference is duration. Brenipatide has been built to last far longer in the body than any current incretin drug, so it is being trialled as a once-a-month injection rather than a weekly one.
How it works — and what it is being tested for
This is where brenipatide breaks from the script. Lilly is not leading with weight loss. The GLP-1 and GIP receptors are also found in the brain’s reward circuitry, and animal work with tirzepatide showed reduced alcohol-seeking and a blunted dopamine surge in response to alcohol. Lilly has taken that idea into people. Its main Phase 3 programme, RENEW, is testing brenipatide in alcohol use disorder (two trials of roughly 1,100 participants each) and bipolar disorder, with earlier-stage studies in depression, opioid use disorder, smoking relapse, schizophrenia, asthma and, further down the list, obesity and heart and liver disease.
In plain terms: this is being developed as a brain-and-addiction medicine that happens to share its chemistry with the weight-loss injections. The monthly dosing is deliberate, because someone in the grip of an addiction is far more likely to keep a monthly appointment than a weekly injection routine.
Who it may be for
If the trials succeed, the first people to benefit will be adults with moderate to severe alcohol use disorder, and possibly people living with bipolar disorder or other conditions where craving, mood and appetite overlap. Whether it will ever be positioned for body composition or “biohacking” is unknown. Lilly has described it as optimised for neuroscience rather than metabolic endpoints.
Who it is not for
At the moment, nobody outside a clinical trial. There are no published efficacy results and no published safety results in humans. Every claim you read about how well it works, how much weight it shifts or how mild its side effects are is either borrowed from tirzepatide data or invented.
When it does arrive, expect the cautions that apply to the whole class: it will not be for pregnancy or breastfeeding, for anyone with a personal or family history of medullary thyroid cancer or the MEN2 syndrome, for people with a history of pancreatitis, or for those with severe gut disorders. It will also interact with other medicines that affect blood sugar. These are class-based expectations, not facts about brenipatide itself – the trials will tell us where it differs.
Likely benefits
Three stand out. A monthly injection instead of a weekly one. A treatment for alcohol dependence that works on craving rather than on willpower, in a field that has had almost no new medicines in a generation. And, if the metabolic effects hold, the familiar incretin benefits of appetite control and better blood-sugar handling as a side benefit rather than the main event.
When can the public expect it?
Not soon. The alcohol trials run for well over a year per participant and were still recruiting in August 2026, so the first readouts are expected from 2027 onwards.
Registration follows results, not the other way round.
A realistic estimate for a first approval in the United States is 2028 at the earliest, with South African registration through SAHPRA some time after that. Anyone quoting you a delivery date is not reading the same documents I am.
The warning that matters most
Brenipatide is a proprietary Lilly molecule. It is not on any compounding list, it cannot be legally compounded by any pharmacy, and it is not registered anywhere in the world.
That means that every vial, pen or “research-grade” powder sold online under this name is counterfeit.
It may contain nothing, it may contain a different peptide altogether, or it may contain something dangerous. Regulators in Australia, the United States, Europe and the United Kingdom have all issued warnings this year about fake incretin products sold on social media, some with no active ingredient at all.
In South Africa, the position is simple: under the Medicines Act, an unregistered medicine may not be sold, and the only lawful route to one is a Section 21 application to SAHPRA, made by a doctor, for a named patient. A website is not a Section 21 pathway.
The bottom line
Brenipatide is one of the most interesting peptides in development, precisely because it is trying to do something new. But interest is not evidence. Until the trials report, the honest description is “promising, unproven, unavailable”. If you are curious, follow the RENEW trial results. If you are offered it, walk away.
Sources: ClinicalTrials.gov NCT07219966 (RENEW-ALC-1) and NCT07412756; Eli Lilly clinical pipeline; TGA, FDA, EMA/HMA and MHRA public warnings on illegally supplied incretin products, 2025–2026; Medicines and Related Substances Act 101 of 1965, ss 14 and 21.
About the author
MBBCh (Wits), Aesthetic Physician, AAAM Board Certified (American Academy of Aesthetic Medicine), AAMSSA member
Dr Susan Burger is a General Practitioner with over 20 years of experience. She specialises in aesthetic medicine and runs a busy practice in Kempton Park, with a core focus on skin health and optimisation.
She is passionate about education and improving the way in which Aesthetic Medicine is practised. As a faculty member of the AAAM (American Academy of Aesthetic Medicine) and local trainer for thread and filler companies in South Africa, she is active in the education of new doctors entering the field of Aesthetic Medicine.
She is a trainer for Mint PDO threads and Fillmed (Filorga) South Africa.
She also regularly presents lectures and performs live treatment demonstrations during the annual Aesthetics Congress in South Africa (AMCSA).