what is the difference
AOD-9604 and growth hormone
A short synthetic fragment set beside the 191 amino acid hormone it was cut from, with the registry and the labelling for each stated separately, because almost everything published belongs to one of them.
Human growth hormone is a 191 amino acid protein released by the pituitary gland, and as a medicine it is somatropin, made by recombinant means. Its FDA-approved labelling carries indications in named paediatric and adult conditions, and the version published on 4 May 2026 is the current one [8]. On 2 August 2026 ClinicalTrials.gov returned 815 registrations naming growth hormone as an intervention [9].
AOD-9604 is a synthetic copy of the last stretch of that hormone. It is usually listed as residues 176 to 191, and a doping-control laboratory that had to detect it in a sample describes the same molecule more exactly, as the C-terminal fragment from amino acids 177 to 191 with an extra tyrosine added at the front end [5]. It is sold for fat loss, and the reason its name carries weight is that the parent hormone's file is large, well known and entirely about the parent hormone.
Not medical advice
This page reports what has been documented about a compound. It is not medical advice, not a diagnosis, not a dosing protocol, and not a recommendation to obtain or use anything described here. Talk to a licensed clinician about anything concerning your health. Read the full disclaimer.
Reviewed against editorial standards Updated
The short answer
Growth hormone is the whole 191 amino acid protein and an approved medicine with 815 registrations naming it [8] [9]. AOD-9604 is a synthetic copy of its last fifteen residues plus one added tyrosine, and no trial of it is registered under AOD9604, AOD-9604 or hGH fragment [9]. What is published on the fragment is animal work in rats, mice and rabbits [1] [2] [3] [4]. A human programme that ended in the 2000s is widely described, and a 2004 drug profile records phase 2a trials underway by February 2002 [7], but no result from it is indexed in PubMed or posted to any registry.
Side by side
| Property | AOD-9604 | Human growth hormone |
|---|---|---|
| What it is | A synthetic copy of the tail end of growth hormone. A doping-control laboratory describes it as the C-terminal fragment from amino acids 177 to 191 with an additional tyrosine at the N-terminus [5] | A 191 amino acid protein released by the pituitary gland, and as a medicine the recombinant form, somatropin [8] |
| Approval status | Not an approved drug in the United States, and no marketing application for it appears in the public record | Approved. The somatropin labelling published 4 May 2026 carries indications in named paediatric and adult conditions [8] |
| Registered human trials | 0 under AOD9604, 0 under AOD-9604, 0 under hGH fragment [9] | 815 records name growth hormone as an intervention [9] |
| Published human studies of this molecule | None indexed in PubMed. A 2004 drug profile in a peer-reviewed journal records that phase 2a trials were underway by February 2002, and reports no result [7] | A literature spanning decades, which belongs to growth hormone and is not summarised here |
| Published work on the fragment | Animal. Obese Zucker rats given it by mouth over 19 days gained about 16 g against about 36 g in controls [1]. Two studies compared it against intact growth hormone on fat handling in obese mice and in mice bred without the beta-3 adrenergic receptor [2] [3], and a rabbit study looked at knee cartilage [4] | Not applicable. The parent hormone's record is human |
| Route in the human programme people cite | Oral, according to the accounts in circulation. The product sold today is for injection, so the two are not the same test | Injection, in the approved labelling [8] |
| Food-ingredient status | A generally recognised as safe status is often claimed. FDA's GRAS Notice Inventory, the public record of notices the agency has responded to, returned no records for AOD9604 or for 9604 on 2 August 2026 [10]. Such a determination is in any case a judgement about a proposed dietary exposure | Not applicable. It is a drug, not a food ingredient |
| Anti-doping analytical position | Published methods exist for detecting it in urine and serum, and one paper reports that it does not interfere with the WADA growth hormone isoform immunoassay [5] [6] | Detected by the isoform immunoassay named in that work [6] |
| Evidence grade on this site | Not graded. A grade is derived from tiered claim rows, and that source review has not been run here | Not graded. An approved medicine's record is out of scope for this catalog |
| What is missing | Any published or registered human study of the fragment, by any route, and any published result from the programme that ended in the 2000s | Nothing that bears on the fragment. The parent's file was never a test of it |
Why the two get mixed up
The naming does most of it. AOD-9604 is commonly listed with the alias hGH fragment 176-191, so the parent hormone's name sits inside the product name and a reader who knows what growth hormone is assumes a known quantity in a smaller package. That alias is accurate as chemistry and misleading as evidence: a copy of the last stretch of a 191 amino acid hormone is a different molecule with its own behaviour in a body.
The second driver is the size of the parent's file: approved labelling, an indication set, and 815 registrations naming growth hormone [8] [9]. Any of that can be quoted next to the fragment without a single word being untrue about the hormone, and none of it tested the fragment. This site's rule is that evidence about a different molecule never sets a grade or a tier for this one, and it was written for cases exactly like this.
The third is a status that gets read as an approval. FDA's GRAS Notice Inventory returned no records for AOD9604 or for 9604 when it was searched on 2 August 2026 [10], and a generally recognised as safe determination is in any case a judgement about a proposed dietary exposure, which says nothing about whether a substance does anything and nothing about injection. The last piece is the route: the programme people cite was oral, the product sold today is for injection, and a trial of one route is not a test of the other.
What the published record covers for each
The published work on the fragment is in animals, and the most cited study is specific about what it measured. In obese Zucker rats given AOD9604 by mouth over 19 days, body-weight gain was about 16 g against about 36 g in untreated controls, fat tissue taken from treated animals showed higher lipolytic activity, meaning a higher rate of fat breakdown, and a euglycaemic clamp found no measurable change in insulin sensitivity [Animal] [1]. Two further studies compared the fragment against intact growth hormone on fat handling after chronic treatment, in obese mice and in mice bred without the beta-3 adrenergic receptor [Animal] [2] [3]. A separate line of work put it somewhere else entirely: 32 rabbits with collagenase-induced knee osteoarthritis received joint injections with or without hyaluronic acid over four to seven weeks, with cartilage scored at eight weeks [Animal] [4]. What this evidence can and cannot show: these results come from rats, mice and rabbits, several of them bred or fed to produce the condition being studied, and the exposure is scaled to body weight in a way that does not translate directly. Mechanism in an animal does not establish an effect in a person.
The analytical literature is the other place this compound has been characterised. A doping-control laboratory validated a urine method for it, identified six potential breakdown products after incubation in serum and urine, and found one of them, a nine amino acid stretch, markedly more stable than the parent compound or the other metabolites [In-vitro] [5]. A separate paper reports that the compound does not interfere with the growth hormone isoform immunoassay used in anti-doping testing [6]. Both are about detecting the molecule rather than about what it does to a body, which is why they carry no claim about effect.
The human side is where this page has to be careful, because a specific story circulates and the primary documents behind it do not. A 2004 drug profile in a peer-reviewed journal records that phase 2a trials were underway by February 2002 and reports no result [7]. Accounts of a larger phase 2 trial that missed its primary endpoint, and of a development programme abandoned in 2007, trace to company announcements rather than to a registry entry or a published paper, so their figures are not restated here. What the primary record holds instead is checkable: nothing from that programme is indexed in PubMed, and no registration exists under any spelling [9].
Growth hormone's own record is large and it belongs to growth hormone: approved labelling published on 4 May 2026 [8] and 815 registrations naming it as an intervention [9]. A 2026 narrative review covers AOD-9604 among the unapproved compounds where animal-model results exist and rigorous human data are scarce [11]. The gap here is not between weak human evidence and strong human evidence. It is between rodent studies and nothing.
Our takeOne molecule has 815 registrations and an approved label. The other has a copy of its last fifteen residues, three rodent studies, a rabbit knee study, and a human programme that left no published paper behind.
Frequently asked questions
Is AOD-9604 the same as growth hormone?
No. Growth hormone is a 191 amino acid protein. AOD-9604 is a synthetic copy of its tail end, described in the analytical literature as the C-terminal fragment from amino acids 177 to 191 with an additional tyrosine at the front [5]. They share a stretch of sequence and nothing else that matters for evidence: the parent's trials tested the parent.
How many human trials has AOD-9604 been in?
None that is registered. ClinicalTrials.gov returned no records for AOD9604, for AOD-9604 or for hGH fragment on 2 August 2026 [9], and no human study of it is indexed in PubMed. A 2004 drug profile in a peer-reviewed journal records that phase 2a trials were underway by February 2002 and gives no result [7].
What about the phase 2 trial people cite?
It is described in secondary accounts rather than in a primary document. This site traces figures to a registry entry, a published paper or an agency record before publishing them, and for that programme the trail ends at company announcements, so the numbers are not restated here [7] [9]. The route matters too: those accounts describe an oral programme, while the product sold today is for injection, and a trial of one route is not a test of the other.
Is it generally recognised as safe?
FDA's GRAS Notice Inventory is the public record of notices the agency has responded to, and searches of it for AOD9604 and for 9604 on 2 August 2026 returned no records [10]. Separately, a generally recognised as safe determination is a judgement about a proposed dietary exposure in food. It is not an efficacy finding, and it authorises nothing about injection.
What has actually been measured?
Animal work and analytical chemistry. In obese Zucker rats given it by mouth over 19 days, body-weight gain was about 16 g against about 36 g in controls [1]. Two studies compared it against intact growth hormone on fat handling in obese mice and receptor knockout mice [2] [3], and a rabbit study looked at knee cartilage [4]. The analytical papers characterise how it breaks down and how it can be detected [5] [6].
References
- Ng FM, Sun J, Sharma L, Libinaka R, Jiang WJ, Gianello R. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res. 2000. PMID 11146367 DOI 10.1159/000053183
- Heffernan M, Summers RJ, Thorburn A, Ogru E, Gianello R, Jiang WJ, Ng FM. 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. PMID 11713213 DOI 10.1210/endo.142.12.8522
- Heffernan MA, Thorburn AW, Fam B, Summers R, Conway-Campbell B, Waters MJ, Ng FM. 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. PMID 11673763 DOI 10.1038/sj.ijo.0801740
- Kwon DR, Park GY. Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model. Ann Clin Lab Sci. 2015. PMID 26275694
- Cox HD, Smeal SJ, Hughes CM, Cox JE, Eichner D. Detection and in vitro metabolism of AOD9604. Drug Test Anal. 2015. PMID 25208511 DOI 10.1002/dta.1715
- Orlovius AK, Thomas A, Schänzer W, Thevis M. AOD-9604 does not influence the WADA hGH isoform immunoassay. Drug Test Anal. 2013. PMID 24124033 DOI 10.1002/dta.1557
- Wilding J. AOD-9604 Metabolic. Curr Opin Investig Drugs. 2004. PMID 15134286 A drug profile recording that phase 2a trials were underway by February 2002. It reports no result
- US National Library of Medicine, DailyMed. GENOTROPIN (somatropin) kit. FDA-approved prescribing information for recombinant human growth hormone, label version published 4 May 2026, carrying indications in named paediatric and adult conditions. DailyMed, set id ffebf88b-d257-4542-9808-74d9b7167765. 2026. Label record
- US National Library of Medicine, ClinicalTrials.gov. Registry searches run through API v2 on 2 August 2026. AOD9604, AOD-9604 and hGH fragment each returned no records. Growth hormone as an intervention returned 815 records. ClinicalTrials.gov. 2026. Registry search
- US Food and Drug Administration. GRAS Notice Inventory, the public record of generally recognised as safe notices submitted to the agency for food ingredients. Searched for AOD9604 and for 9604 on 2 August 2026; both searches returned no records. FDA, Center for Food Safety and Applied Nutrition. 2026. GRAS inventory
- Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Med. 2026. PMID 41966639 DOI 10.1007/s40279-026-02437-0