--- title: "AOD-9604: Benefits, Dosage, Side Effects & Trial Results" description: "AOD-9604 is a growth hormone fragment that burned fat in mice but missed its goal in a 24-week human trial. How it works, side effects and what went wrong." canonical: "https://www.vitalsvault.com/peptides/aod-9604" last-updated: 2026-08-22 --- # AOD-9604: Benefits, Dosage, Side Effects & Trial Results > AOD-9604 is a growth hormone fragment that burned fat in mice but missed its goal in a 24-week human trial. How it works, side effects and what went wrong. ![A woman in her mid forties stands on a red rock desert trail holding a water bottle, small daypack, wide brim hat, late morning sun](https://www.vitalsvault.com/_next/image?url=%2Fpublic-v3%2Fshoot%2Fpeptides%2Fpep-aod9604.webp&w=3840&q=75&dpl=shadow-production-f0162cb4d465-40992538108-1) Peptide Guide · Metabolism and weight # AOD-9604 Anti-Obesity Drug 9604, hGH 177-191 with a tyrosine AOD-9604 had everything an obesity drug needs in mice. Then about 500 people joined a 24-week trial, and the weight loss did not show up. [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist)[Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) Free to join · One email when peptide care opens · Most lab results in 3–5 business days Studied forFat metabolism and obesity EvidenceEarly human data Taken asBy mouth in the obesity trials; online protocols mostly describe injections Studied forFat metabolism and obesity EvidenceEarly human data Taken asBy mouth in the obesity trials; online protocols mostly describe injections ## AOD-9604, in short AOD-9604 is a 16-amino-acid peptide copied from the tail of human growth hormone, with one added tyrosine. In rodents it pushed fat cells to release stored fat and slowed fat building, without the rise in blood sugar that growth hormone causes. It was developed as an obesity drug, but a 24-week human trial of about 500 people missed its weight-loss goal. Medically reviewed by [Robert Lufkin, MD (opens in a new tab)](https://www.robertlufkinmd.com/) Chief Medical Officer, Vitals Vault · Updated October 29, 2026 · 16 sources ## At a glance Early human data TypeSynthetic peptide, 16 amino acids[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015) Derived fromThe C-terminal tail of human growth hormone (residues 177 to 191) plus a tyrosine[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015) Studied forFat breakdown and obesity[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) Best human dataA 24-week phase 2 obesity trial that missed its primary weight-loss endpoint[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) Taken asBy mouth in the obesity trials; online protocols mostly describe injections[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) FDA statusNot approved. Listed among compounding substances nominated and later withdrawn[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks) SportBanned by WADA as a growth hormone fragment[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015)[16](https://www.vitalsvault.com/peptides/aod-9604#source-wada) ## Before you consider AOD-9604 - Safety FDA says it lacks enough information to know whether compounded AOD-9604 would cause harm. A sponsor-reported trial program described mild headache, fatigue and injection reactions.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) [Side effects and safety](https://www.vitalsvault.com/peptides/aod-9604#safety) - Legal status Not FDA approved. FDA lists it among substances that were nominated for compounding and later withdrawn.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks) [FDA status](https://www.vitalsvault.com/peptides/aod-9604#fda-status) - How it’s taken The obesity trials used capsules or tablets by mouth. Products sold outside research are often injectables of unknown purity.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) [Forms and dosage](https://www.vitalsvault.com/peptides/aod-9604#how-taken) ## How does AOD-9604 work? In animals, AOD-9604 pushed fat cells to let go of stored fat. - ### Helps fat cells release fat In rat fat tissue, its parent fragment helped release stored fat. In obese mice, AOD-9604 itself raised fat burning.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000)[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b) - ### Slows new fat building The parent fragment also slowed a key step the body uses to make new fat, in rat fat tissue.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) - ### Leaves blood sugar alone Unlike growth hormone, AOD-9604 did not raise blood sugar in obese mice.[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b) ## AOD-9604 benefits: what it is studied for The animal results are real. In people, the one large trial did not show a weight-loss benefit. 1. Animal study01 ### Less weight gain in obese rodents Obese mice treated for 14 days lost body weight and body fat, and obese rats gained less weight over 20 days.[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) 2. Lab study02 ### Fat cell activity in human tissue In isolated human and rodent fat tissue, a closely related fragment raised fat breakdown and lowered fat production.[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000) 3. Animal study03 ### Cartilage in a rabbit model Injected into the knee, it reduced cartilage damage in a rabbit osteoarthritis model. This has not been tested in people.[6](https://www.vitalsvault.com/peptides/aod-9604#source-kwon-2015) ## What the research shows Early human data 1. 1 · Cells in a lab Studied In isolated human and rodent fat tissue, a closely related fragment raised fat breakdown and lowered fat production.[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000) Shows a mechanism 2. 2 · Animals Studied Obese mice lost weight and body fat in 14 days, and obese rats gained less weight over 20 days.[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) Shows an effect in a body 3. 3 · People Studied A 24-week trial in 502 adults with obesity missed its main weight-loss goal. The result was sponsor-reported, not a published trial paper.[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) Shows it works in people The preclinical work is consistent. Monash University researchers showed the fragment lowered fat and body weight in obese rodents without the blood sugar effects of growth hormone. In humans, a 24-week phase 2 study failed to show a significant benefit on its primary weight-loss endpoint, according to a 2026 review that relies on sponsor-reported outcomes rather than a peer-reviewed trial paper.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) The review describes the drug as generally well tolerated in that program, with mild headache, fatigue and injection reactions, and notes that long-term safety data are not available.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) The full guide to AOD-9604 10 min read · Medically reviewed by Robert Lufkin, MD ## AOD-9604: the obesity drug that failed its big test In 2007, a Melbourne drug company called Metabolic Pharmaceuticals told the Australian stock exchange that its obesity program was over. Its drug had just been through a 24-week trial in about 500 people, and it had not produced a significant benefit on the trial’s main weight-loss measure. The company said the results did not support taking it further. That drug was AOD-9604. Failed drug candidates usually vanish from view. AOD-9604 did the opposite. It turned up for sale on websites and in confiscated vials in the United States, and anti-doping scientists built a urine test to catch athletes using it. A molecule that could not beat placebo in a large trial had found a second life on the strength of its animal results and its story. That story deserves to be told properly, because it holds a lesson for almost every fat-loss peptide sold today. AOD-9604 had about the best early case a weight-loss molecule could have, with a clear mechanism, results in several rodent models, activity in human fat tissue in a dish, and no sign of growth hormone’s effect on blood sugar. It still did not deliver in people. To see why, start with the hormone it came from.[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026)[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015)[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000)[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) ## How growth hormone burns fat, and why scientists cut it into pieces Growth hormone is a protein of 191 amino acids made by the pituitary gland, and it does more than one job. It drives growth in children, helps maintain muscle and bone in adults, and pushes fat cells to release their stored fuel. It also works against insulin, which is why too much growth hormone can raise blood sugar. For anyone hoping to use it against obesity, that last effect is a serious problem. Frank Ng and his colleagues in Australia spent years asking whether the fat-burning part of the hormone could be separated from the rest. In 1978, Ng and a colleague tested short synthetic pieces from the hormone’s tail end in rats and found that several of them changed blood sugar and insulin. In 1993, working at Monash University, the group showed that the piece made of residues 177 to 191 slowed fat production in rat fat tissue as strongly as the whole hormone. By 2000 the Monash team had a candidate. Their synthetic 177 to 191 piece, then called AOD9401, switched on hormone-sensitive lipase, the enzyme that releases stored fat, and switched off acetyl CoA carboxylase, a key enzyme for building new fat. In obese Zucker rats treated for 20 days it slowed weight gain and shrank the average fat cell from about 110 to 80 micrometers across. Unlike growth hormone, it did not cause insulin resistance. The version that went forward added one amino acid, a tyrosine, to the front of the chain. That 16-amino-acid peptide is AOD-9604, and the letters stand for anti-obesity drug. Metabolic Pharmaceuticals took it into human testing, and phase 2a trials were underway by early 2002.[9](https://www.vitalsvault.com/peptides/aod-9604#source-ng-1978)[10](https://www.vitalsvault.com/peptides/aod-9604#source-wu-1993)[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000)[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015)[4](https://www.vitalsvault.com/peptides/aod-9604#source-wilding-2004) ## How AOD-9604 works in fat cells Inside every fat cell, two processes pull against each other all day. One builds fat from incoming fuel and stores it. The other breaks stored fat back down into fatty acids the body can burn. Insulin tilts the balance toward storage, while growth hormone and adrenaline tilt it toward release. AOD-9604 was designed to lean on the release side without touching insulin. In rat fat tissue, its parent fragment AOD9401 copied both of the whole hormone’s moves, raising the activity of hormone-sensitive lipase and lowering acetyl CoA carboxylase. Obese mice treated with AOD-9604 burned more fat, measured as higher fat oxidation and higher blood glycerol, a by-product released when stored fat is broken down. In a short experiment it also raised energy expenditure, even in mice lacking beta-3 receptors. AOD-9604 also lacked the effects its designers wanted to avoid. In a cell test it did not compete for the growth hormone receptor, and cells carrying that receptor did not multiply in response. In obese mice it did not raise blood sugar or lower insulin secretion the way full growth hormone did. That separation was the whole point of the project, and in animals it held. One more detail turned out to matter. Its weight effect in mice was tied to beta-3 adrenergic receptors, receptors on fat cells that respond to adrenaline. Treatment raised the low beta-3 receptor RNA levels of obese mice to levels comparable with lean mice, and in mice bred without beta-3 receptors, long-term treatment no longer changed body weight. Keep that receptor in mind. It returns when the story reaches people.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000)[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b) ## AOD-9604 benefits in animals: what the studies showed The animal record is consistent, and it spans more than one model. Genetically obese ob/ob mice were given the parent fragment by mouth for 30 days, 10 on the peptide and 8 on saline. From day 16 onward the treated mice gained significantly less weight. Food intake did not differ between the groups, so the effect did not come from eating less. Fourteen days of AOD-9604 injections reduced body weight and body fat in obese mice, and 14 days by a small slow-release pump significantly reduced their weight gain. Obese Zucker rats given the parent fragment gained less weight over 20 days. Across these later studies the direction was the same, and none reported the blood sugar rise that growth hormone causes, a contrast with the 1978 work on other tail fragments. There was even a hint that the effect might cross species. In isolated fat tissue taken from obese rodents and from people, the parent fragment raised fat breakdown and lowered fat production. That result, published in 2000, gave the program a strong reason to move into human trials.[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b)[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) ## What happened when AOD-9604 was tested in people Phase 2a studies were underway by early 2002, and the program built toward a larger test of a form taken by mouth. According to a 2026 review of growth hormone-axis peptides, that 24-week trial enrolled 534 people, randomized 502 and failed to show a significant benefit on its primary weight-loss endpoint. In 2007 the company told the Australian stock exchange that the results did not support commercial viability and ended the obesity program. There is a caveat about the evidence itself. The same review notes that what we know about this failure comes mainly from the sponsor’s reported phase 2 outcomes rather than a peer-reviewed paper of the randomized trial. So the most important human study of AOD-9604 does not appear, in that review, as a peer-reviewed trial paper open to independent scrutiny. We cannot inspect the failure in detail, and nobody can point to a hidden success inside it either. The safety side held up better. The review describes AOD-9604 in human studies as generally well tolerated, with mild, short-lived headache, fatigue and injection reactions. It reports no significant change in glucose tolerance and no meaningful rise in IGF-1, the growth factor that full growth hormone drives up. The separation from growth hormone that worked in mice seemed to work in people. The fat loss is what failed to carry over. The reviewers place AOD-9604 between their middle and lowest evidence tiers. Short-term human trials exist, but their signals are limited, and no reliable data show a meaningful loss of visceral fat or a wider metabolic benefit. Claims that it reshapes body composition or improves performance remain, in their word, speculative.[4](https://www.vitalsvault.com/peptides/aod-9604#source-wilding-2004)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) ## Why a fat burner that worked in mice fizzled in people The ob/ob mouse and the Zucker rat, the two obese rodents where AOD-9604 shone, have a long history in obesity drug research. Drug companies used the same kinds of animals to develop beta-3 adrenergic agonists, drugs that switch on the beta-3 receptor in fat. In those rodents, beta-3 drugs raised fat breakdown and heat production in brown fat, improved blood sugar handling and cut body weight. At least nine beta-3 agonists went on to human trials. Every one of those programs was stopped, because none produced a clinically relevant change in body weight. A 2023 review traced the failure to differences between species, explaining why a receptor that does so much in rodent metabolism is not a meaningful obesity target in people. Now recall the knockout mice. AOD-9604 lost its weight effect in mice without beta-3 receptors, and part of its action in obese mice was to raise beta-3 receptor RNA. The Monash team concluded that the peptide does not act directly through that receptor. Even so, its weight loss in rodents leaned on the same circuit that the beta-3 drugs relied on, the circuit that repeatedly failed to move human body weight. This remains a hypothesis. None of the studies cited here tested AOD-9604 in people while measuring the beta-3 pathway, and the trial data are not public in full. It does offer a plausible answer to the question every failed obesity drug raises, and it carries a wider lesson. When a fat-loss peptide’s case rests on ob/ob mice and Zucker rats, look hard for human trials, because those animals have flattered drugs before.[11](https://www.vitalsvault.com/peptides/aod-9604#source-dwaib-2023)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) Know your baseline before any peptide 120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start AOD-9604 later. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans)[Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) Full refund before your blood draw · No membership ## AOD-9604 for joints and cartilage: one rabbit study Years after the obesity program ended, a different use appeared in the literature. In 2015, researchers in South Korea damaged the knee cartilage of 32 rabbits to mimic osteoarthritis and then gave injections into the joint of saline, hyaluronic acid, AOD-9604, or AOD-9604 with hyaluronic acid. Hyaluronic acid is a lubricating gel already injected into human knees. Both AOD-9604 groups had less cartilage damage than the saline group, judged by how the joint looked and how the tissue appeared under the microscope. The combination did best, with lower damage scores than either treatment alone and a shorter period of limping than any other group. That single study, in a chemically induced model from one research group, is the only joint study of AOD-9604 we found. A 2026 review notes the lack of convincing human trial evidence for osteoarthritis, joint repair or tissue regeneration. It is an interesting lead, and it should be described as exactly that.[6](https://www.vitalsvault.com/peptides/aod-9604#source-kwon-2015)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) ## AOD-9604 side effects and safety In the human program, side effects were described as mild and short-lived, mainly headache, fatigue and reactions at the dosing site. The 2026 review reports no significant change in glucose tolerance or IGF-1, and notes that no long-term safety data are available. FDA takes a more cautious view. Its compounding safety page lists AOD-9604 among substances nominated for compounding and later withdrawn, and it flags possible immunogenicity, meaning the body may mount an immune response to the peptide, along with impurities linked to how peptides are made. FDA says it has little or no safety information and has identified serious adverse events that may be associated with AOD-9604, though it could not establish cause. The product in a vial today is a separate question from the molecule tested in trials. The obesity trials used a form taken by mouth, while the online protocols the 2026 review collected describe injections. A 2026 clinical review describes an identity gap in unregulated peptides, meaning uncertain composition, sterility and purity, sitting on top of the evidence gap. Some people should be especially careful, including anyone taking insulin or other glucose-lowering medicine, anyone pregnant or breastfeeding, anyone with a history of cancer, and anyone who competes in tested sport.[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026)[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks) ## The labs that show whether fat loss is working AOD-9604 was built around one promise, fat loss without the blood sugar cost of growth hormone. Whatever approach you take to body fat, that promise is worth checking in your own blood. Fasting glucose and fasting insulin together show how hard your body works to keep sugar in range, and a high insulin alongside a normal glucose can be an early hint of insulin resistance, though fasting insulin is not a standalone diagnostic test. HbA1c, glycated hemoglobin, reflects your average blood sugar over about three months, so it shows the trend rather than a single morning. ALT is a liver enzyme that rises when liver cells are under stress, and fatty liver is one of the most common places where excess body fat does quiet damage. Vitals Vault does not offer AOD-9604. These markers give a clinician baseline metabolic context, chosen around your own risk, and a retest shows how that metabolic picture moves. Body fat itself needs its own measurement. ## Is AOD-9604 legal? Where it stands in 2026 AOD-9604 is not an FDA-approved drug for any use. FDA’s compounding safety page, current as of April 22, 2026, lists it among bulk substances that were nominated for compounding and then withdrawn, and it notes immunogenicity and impurity concerns. Sport has its own rule. The World Anti-Doping Agency prohibits growth hormone fragments and names AOD-9604 as an example. Anti-doping scientists have published a urine test that detects the peptide and a stable breakdown product, which may extend the window in which use can be caught.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks)[16](https://www.vitalsvault.com/peptides/aod-9604#source-wada)[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015) ## What this means for you AOD-9604 is one of the rare fat-loss peptides that was tested the way a drug should be, in a large randomized trial, and it did not deliver. Its animal results were real and its blood sugar safety seemed to carry over to people, yet the weight loss did not. A 2026 review of the evidence found nothing that changes that picture. The lesson reaches well beyond this one molecule. A mechanism that works in a dish and in an obese mouse earns a human trial, and AOD-9604 got one. If you are weighing any fat-loss compound, the next question worth asking is whether it has beaten placebo in people, and if it has not, what would make you expect it to work in you.[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) Know your baseline before any peptide 120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start AOD-9604 later. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans)[Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) Full refund before your blood draw · No membership ## What to expect with AOD-9604 There is no reliable human timeline for fat loss with AOD-9604, because its main trial did not show a significant weight-loss effect over 24 weeks. In obese mice, the gap in weight gain appeared after about two weeks of treatment, which is a mouse timescale and should not be read as a human one. If your goal is body fat, a more useful clock is the one on your labs. Fasting insulin and glucose respond within weeks to changes in diet, sleep and training, and HbA1c reflects about three months, so a retest at that point shows whether your plan is moving your metabolism.[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026)[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000) ## Key AOD-9604 studies - Ng et al., 2000[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) Animal and tissue study · Obese Zucker rats, treated for 20 days Slowed weight gain and shrank fat cells, with no insulin resistance Limits: Rats; used the 177 to 191 parent fragment - Heffernan et al., 2000[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000) Animal and tissue study · Obese mice given it by mouth (10 treated, 8 controls); human fat tissue in a dish Less weight gain from day 16 with no change in food intake; more fat breakdown in human fat tissue Limits: Fat tissue in a dish does not show whole-body fat loss - Heffernan et al., 2001 (Endocrinology)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[11](https://www.vitalsvault.com/peptides/aod-9604#source-dwaib-2023) Animal study, including knockout mice · Obese mice and mice lacking beta-3 receptors Lower body weight and fat after 14 days; no weight effect without beta-3 receptors Limits: Mice; relied on a pathway that matters less in humans - Heffernan et al., 2001 (Int J Obes)[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b) Animal and cell study · Obese and lean mice; cells carrying the growth hormone receptor More fat burning, no high blood sugar, no binding to the growth hormone receptor Limits: Mice and cells only - Phase 2b obesity trial (sponsor-reported)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) Randomized trial, 24 weeks, taken by mouth · 534 enrolled, 502 randomized Missed its primary weight-loss endpoint; side effects mild Limits: Not published as a peer-reviewed trial paper - Kwon and Park, 2015[6](https://www.vitalsvault.com/peptides/aod-9604#source-kwon-2015) Animal study · 32 rabbits with induced knee osteoarthritis Less cartilage damage; best results combined with hyaluronic acid Limits: One rabbit study; no human data Key studies on AOD-9604 | Study | Design | Who | What it found | Limits | | --- | --- | --- | --- | --- | | Ng et al., 2000[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) | Animal and tissue study | Obese Zucker rats, treated for 20 days | Slowed weight gain and shrank fat cells, with no insulin resistance | Rats; used the 177 to 191 parent fragment | | Heffernan et al., 2000[2](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2000) | Animal and tissue study | Obese mice given it by mouth (10 treated, 8 controls); human fat tissue in a dish | Less weight gain from day 16 with no change in food intake; more fat breakdown in human fat tissue | Fat tissue in a dish does not show whole-body fat loss | | Heffernan et al., 2001 (Endocrinology)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[11](https://www.vitalsvault.com/peptides/aod-9604#source-dwaib-2023) | Animal study, including knockout mice | Obese mice and mice lacking beta-3 receptors | Lower body weight and fat after 14 days; no weight effect without beta-3 receptors | Mice; relied on a pathway that matters less in humans | | Heffernan et al., 2001 (Int J Obes)[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b) | Animal and cell study | Obese and lean mice; cells carrying the growth hormone receptor | More fat burning, no high blood sugar, no binding to the growth hormone receptor | Mice and cells only | | Phase 2b obesity trial (sponsor-reported)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) | Randomized trial, 24 weeks, taken by mouth | 534 enrolled, 502 randomized | Missed its primary weight-loss endpoint; side effects mild | Not published as a peer-reviewed trial paper | | Kwon and Park, 2015[6](https://www.vitalsvault.com/peptides/aod-9604#source-kwon-2015) | Animal study | 32 rabbits with induced knee osteoarthritis | Less cartilage damage; best results combined with hyaluronic acid | One rabbit study; no human data | ## AOD-9604 myths and evidence - ### AOD-9604 is a proven fat burner It reduced weight gain and body fat in obese rodents. In people, a 24-week trial with 502 participants randomized did not show a significant weight-loss benefit on its main measure, and the developer ended the program.[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) - ### AOD-9604 is just growth hormone in a smaller package It was designed to be the opposite. In a cell test it did not compete for the growth hormone receptor or make cells multiply, and the 2026 review reports no meaningful rise in IGF-1 and no significant change in glucose tolerance in human studies.[8](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001b)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) - ### AOD-9604 rebuilds cartilage One study in 32 rabbits found less cartilage damage after joint injections, especially with hyaluronic acid. A 2026 review found no convincing human trial evidence for osteoarthritis or joint repair.[6](https://www.vitalsvault.com/peptides/aod-9604#source-kwon-2015)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) - ### AOD-9604 and Fragment 176-191 are the same thing They are one amino acid apart. Human growth hormone has a phenylalanine at position 176, and AOD-9604 has a tyrosine there. Labels often blur the two, and AOD-9604 is the one that went through human obesity trials; none of the sources here describe human trials of Fragment 176-191.[14](https://www.vitalsvault.com/peptides/aod-9604#source-uniprot-gh1)[5](https://www.vitalsvault.com/peptides/aod-9604#source-cox-2015)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) Know your baseline first 120+ lab tests at Quest, every result reviewed by a licensed clinician. Most results in 3–5 business days. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) ## How is AOD-9604 taken? Some human studies of AOD-9604 used an oral form. Products sold outside clinical research are often injectables of unknown purity. FDA has flagged peptide-related impurities and immunogenicity as concerns for compounded versions.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks)[7](https://www.vitalsvault.com/peptides/aod-9604#source-dominikowski-2026) ## AOD-9604 dosage There is no FDA-approved dose of AOD-9604 for any use. The human trials gave it as a daily capsule or tablet for up to 24 weeks in adults with obesity, or as single test infusions into a vein. FDA found no human data for injection under the skin or for creams, the forms sold today. Your clinician sets your dose, if any.[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) ## Typical AOD-9604 dosage Six company-run trials in about 900 adults, most with obesity, gave AOD-9604 by mouth once a day for up to 24 weeks, or as single infusions into a vein. In the 12-week trial the lowest daily dose did best, and in the larger 24-week trial no dose beat placebo for weight loss. FDA found no human data for injection under the skin. A clinician sets any actual dose. These are reference doses from FDA labels, studies in people and clinical practice reports, shown for education. They are not a recommendation or a prescription. Your dose, form and schedule should be set by a licensed clinician who knows your history and lab results. Already have a prescribed dose? The [peptide dosage calculator](https://www.vitalsvault.com/peptides/tools/dosage-calculator) turns it into the units to draw on an insulin syringe. - Human trial · Tablet by mouth 0.25 mg, 0.5 mg or 1 mg Once daily[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) 502 adults with obesity, for 24 weeks - Human trial · Capsule by mouth 1, 5, 10, 20 or 30 mg Once daily[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) 300 adults with obesity, for 12 weeks; the 1 mg group lost the most weight - Human trial · Capsule by mouth 9, 27 or 54 mg Once daily[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013) 36 men with obesity, for 7 days (safety study) - Human trial · Infusion into a vein 25 to 400 µg/kg Single doses[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) Early safety studies in men Typical AOD-9604 doses in people, by source | Source | Form | Amount | How often | Notes | | --- | --- | --- | --- | --- | | Human trial[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) | Tablet by mouth | 0.25 mg, 0.5 mg or 1 mg | Once daily | 502 adults with obesity, for 24 weeks | | Human trial[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) | Capsule by mouth | 1, 5, 10, 20 or 30 mg | Once daily | 300 adults with obesity, for 12 weeks; the 1 mg group lost the most weight | | Human trial[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013) | Capsule by mouth | 9, 27 or 54 mg | Once daily | 36 men with obesity, for 7 days (safety study) | | Human trial[12](https://www.vitalsvault.com/peptides/aod-9604#source-stier-2013)[13](https://www.vitalsvault.com/peptides/aod-9604#source-fda-pcac-aod-2024) | Infusion into a vein | 25 to 400 µg/kg | Single doses | Early safety studies in men | ## Is AOD-9604 right for you? A clinician makes the call. These are the questions they will ask first. ### It may suit - Adults curious about the research behind growth hormone fragments - People who want a clinician to review their metabolic labs before considering any weight-loss strategy ### Talk to a clinician first if you are - Pregnant or breastfeeding - Taking insulin or other glucose-lowering medicine - Competing in tested sport, because AOD-9604 is banned - A history of cancer, because growth hormone pathways influence cell growth - Any condition of the liver, kidneys or immune system Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest. [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) ## Fat storage runs on hormonal signals Body fat is stored and released under hormonal control. Insulin tilts fat cells toward storing, while growth hormone and adrenaline tilt them toward releasing. AOD-9604 tried to push the release side from one small piece of growth hormone, and the human trial did not show a significant weight-loss benefit. A single signal did not move the balance the way rodent studies implied, so the wider picture is worth measuring in your own labs.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000)[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001) ### What else moves the same system 1. 01Lower the insulin loadProtein-forward meals and fewer refined carbohydrates are common ways to ease the all-day insulin signal. 2. 02Build muscleResistance training raises the tissue that clears glucose and burns fuel at rest. 3. 03Protect sleepShort sleep raises appetite and lowers insulin sensitivity within days. 4. 04Track the trendFasting insulin, glucose and HbA1c show whether the metabolic picture is improving. ## Labs to check with AOD-9604 A blood test before you start and a retest after shows what actually changed for you. It is how Vitals Vault approaches every treatment. 1. TestA baseline panel at Quest Diagnostics. 2. DecideA licensed clinician reviews your history and results. 3. RetestThe same markers again, side by side. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) - [HbA1cYour average blood sugar over about three months.](https://www.vitalsvault.com/biomarkers/hemoglobin-a1c) - [Fasting insulinShows insulin resistance earlier than glucose alone.](https://www.vitalsvault.com/biomarkers/insulin) - [Fasting glucoseA simple metabolic marker to retest.](https://www.vitalsvault.com/biomarkers/glucose) - [Liver enzymes (ALT)Part of a metabolic panel. Checks the liver before and during any new prescription.](https://www.vitalsvault.com/biomarkers/alt) ## Is AOD-9604 FDA approved? No. AOD-9604 is not an FDA-approved drug. FDA’s compounding safety page (current as of April 22, 2026) lists it among bulk substances that were nominated for compounding and later withdrawn. FDA noted possible immunogenicity and impurity concerns, said it had identified no or only limited safety information, and said it had identified serious adverse events that may be associated with it, though causality is not clear.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks) ### AOD-9604 timeline 1. 2000 Monash University researchers report the lipolytic domain of human growth hormone (AOD9401) lowers weight gain in obese rats.[1](https://www.vitalsvault.com/peptides/aod-9604#source-ng-2000) 2. 2001 AOD9604 reduces body weight and fat in obese mice after 14 days of treatment.[3](https://www.vitalsvault.com/peptides/aod-9604#source-heffernan-2001) 3. 2002 Metabolic Pharmaceuticals has phase 2a obesity trials of AOD-9604 underway.[4](https://www.vitalsvault.com/peptides/aod-9604#source-wilding-2004) 4. April 2026 FDA’s compounding safety page lists AOD-9604 among nominated substances that were withdrawn, citing immunogenicity, impurity and limited safety data.[15](https://www.vitalsvault.com/peptides/aod-9604#source-fda-bulks) ![A South Asian man, 68, slender, full white hair, white moustache, kurta-collar shirt reads in a lamp-lit nook](https://www.vitalsvault.com/_next/image?url=%2Fpublic-v3%2Fshoot%2Fpeptides%2Ffaq-aod9604.webp&w=3840&q=75&dpl=shadow-production-f0162cb4d465-40992538108-1) ## AOD-9604 questions What is AOD-9604 used for? AOD-9604 is studied for fat loss and obesity. It was developed as a drug for obesity but never approved. Some people also ask about it for joint health, which has only been tested in rabbits. What are the benefits of AOD-9604? In obese rodents it lowered body weight and fat without the blood sugar effects of growth hormone. In people, a 24-week phase 2 trial did not show a significant weight-loss benefit on its primary endpoint. How does AOD-9604 work? It mimics the fat-burning region of growth hormone. In fat tissue it activates hormone-sensitive lipase, which releases stored fat, and it reduces fat production. What are the side effects of AOD-9604? The sponsor-reported program described mild headache, fatigue and injection reactions. FDA has said it lacks enough information to know whether compounded AOD-9604 would cause harm, and noted serious adverse events that may be associated with it. What is the AOD-9604 dosage? There is no FDA-approved dose. Human trials gave it as a daily capsule or tablet for up to 24 weeks, and the study doses are listed in the dosage table on this page. FDA found no human data for injection under the skin. Your clinician sets your dose. AOD-9604 vs fragment 176-191, what is the difference? Both copy the last 16 amino acids of human growth hormone, and they differ by one. AOD-9604 starts with a tyrosine where the natural sequence has a phenylalanine. AOD-9604 went through human obesity trials; none of the sources here describe human trials of Fragment 176-191. Online labels often blur the two. Why did AOD-9604 fail as an obesity drug? A 24-week trial of an oral form, with 502 people randomized, did not show a significant benefit on its main weight-loss measure, and the developer ended the program in 2007. One hypothesis is that its rodent results relied on a fat-burning pathway that matters far less in humans. Is AOD-9604 FDA approved? No. FDA’s April 2026 compounding safety page lists AOD-9604 among substances that were nominated and then withdrawn, and says the agency lacks enough information to know whether it would cause harm. Is AOD-9604 banned in sport? Yes. The World Anti-Doping Agency prohibits growth hormone fragments, and AOD-9604 is one of the named examples. Athletes in tested sport should not use it. Can I get AOD-9604 through Vitals Vault? Not at this time. Vitals Vault is opening clinician-led peptide care that starts with a blood test, and AOD-9604 is not part of it. Join the peptides waitlist to hear what is offered. ## Peptides, prescribed and measured Vitals Vault is opening peptide care that starts with your blood work, is prescribed by licensed US clinicians and ends with a retest. Join the waitlist to hear first. - Prescription only - Licensed US clinicians - Quest Diagnostics labs [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist)[Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) ## Keep reading [Full Peptide Guide](https://www.vitalsvault.com/peptides) - Fragment 176-191The last 16 amino acids of human growth hormone, studied in animals for fat metabolism. It has no human efficacy trials. - MOTS-cA peptide coded in your mitochondrial DNA, studied for insulin sensitivity, weight and exercise capacity. - TesamorelinAn FDA-approved growth hormone releasing factor analog (Egrifta) for excess abdominal fat in adults with HIV-associated lipodystrophy. - FDA peptide update 2026What FDA’s October 2026 decision on six peptides means for you. - 5-Amino-1MQA small molecule that blocks the enzyme NNMT. It is sold next to peptides but is not one. Studied in obese mice. ## Sources 1. 1. [Ng FM, et al. Molecular and cellular actions of a structural domain of human growth hormone (AOD9401) on lipid metabolism in Zucker fatty rats. J Mol Endocrinol. 2000 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/11116208/) 2. 2. [Heffernan MA, et al. Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism. Am J Physiol Endocrinol Metab. 2000 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/10950816/) 3. 3. [Heffernan M, et al. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology. 2001 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/11713213/) 4. 4. [Wilding J. AOD-9604 Metabolic. Curr Opin Investig Drugs. 2004 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/15134286/) 5. 5. [Cox HD, et al. Detection and in vitro metabolism of AOD9604. Drug Test Anal. 2015 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/25208511/) 6. 6. [Kwon DR, et al. Effect of intra-articular injection of AOD9604 with or without hyaluronic acid in rabbit osteoarthritis model. Ann Clin Lab Sci. 2015 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/26275694/) 7. 7. [Dominikowski A, et al. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis. Front Endocrinol (Lausanne). 2026 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/42395176/) 8. 8. [Heffernan MA, et al. Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment. Int J Obes Relat Metab Disord. 2001 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/11673763/) 9. 9. [Ng FM, et al. Hyperglycemic action of synthetic C-terminal fragments of human growth hormone. Am J Physiol. 1978 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/645904/) 10. 10. [Wu Z, et al. Antilipogenic action of synthetic C-terminal sequence 177-191 of human growth hormone. Biochem Mol Biol Int. 1993 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/8358331/) 11. 11. [Dwaib HS, et al. Is the beta3-adrenoceptor a valid target for the treatment of obesity and/or type 2 diabetes? Biomolecules. 2023 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/38136585/) 12. 12. [Stier H, Vos E, Kenley D. Safety and tolerability of the hexadecapeptide AOD9604 in humans. J Endocrinol Metab. 2013;3(1-2):7-15 (opens in a new tab)](https://jofem.org/index.php/jofem/article/view/157) 13. 13. [FDA. Pharmacy Compounding Advisory Committee briefing document: AOD-9604-related bulk drug substances. December 4, 2024 (opens in a new tab)](https://www.fda.gov/media/183584/download) 14. 14. [UniProt. P01241, Somatotropin (human growth hormone), amino acid sequence (opens in a new tab)](https://www.uniprot.org/uniprotkb/P01241/entry) 15. 15. [FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (current as of April 22, 2026) (opens in a new tab)](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) 16. 16. [World Anti-Doping Agency. Prohibited List (opens in a new tab)](https://www.wada-ama.org/en/prohibited-list) Written by the Vitals Vault editorial team, medically reviewed by Robert Lufkin, MD, and updated October 29, 2026. This is general education, not medical advice. None of these peptides is FDA-approved to diagnose, treat, cure or prevent any disease, and compounded medicines are not FDA-reviewed for safety, effectiveness or quality. Talk to a licensed clinician before starting any treatment. --- Canonical HTML: https://www.vitalsvault.com/peptides/aod-9604 - [llms.txt](https://www.vitalsvault.com/llms.txt) - [sitemap.xml](https://www.vitalsvault.com/sitemap.xml) - [Developer portal](https://www.vitalsvault.com/developers)