AOD-9604

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Also referred to as hGH Fragment 176-191.

Status: Investigational. AOD-9604 is not an FDA-approved drug product. It is a fragment of the human growth hormone molecule, specifically the region spanning amino acids 176 to 191, that was investigated as a potential obesity treatment in human clinical trials. Those trials did not establish a meaningful weight-loss or fat-loss benefit at the exposures studied, and no approval followed. It remains investigational and is not a recognized standard-of-care treatment for weight loss or body composition.

AOD-9604 is a fragment of the human growth hormone molecule, corresponding to amino acids 176 to 191, that was specifically developed and tested as a potential treatment for obesity. Human clinical trials conducted for that purpose did not demonstrate a meaningful weight-loss or fat-loss effect at the exposures studied, and the substance was not approved as a result. It is not an FDA-approved drug product, and its history is a useful, direct illustration of how a peptide can advance through human testing and still fail to show worthwhile benefit. This page states that outcome plainly rather than treating AOD-9604 as an open or promising question.

What it is

AOD-9604 is a synthetically produced fragment corresponding to the C-terminal region (amino acids 176 to 191) of the human growth hormone molecule. It was engineered specifically to isolate the region of growth hormone proposed to be involved in fat metabolism, while attempting to exclude the region responsible for growth-promoting and insulin-resistance effects associated with full-length growth hormone. It has been studied as an injectable and, in some development programs, as an oral formulation, though it is not an approved drug in either form.

Why people ask about it

Patients researching growth hormone-related weight loss options sometimes encounter AOD-9604 marketed informally as a 'fat-burning fragment' of growth hormone without full context that it was tested in human obesity trials and did not succeed. Understanding that history directly answers the most common question about it.

Proposed mechanism

AOD-9604 was proposed, based on animal and early metabolic research, to stimulate lipolysis (fat breakdown) and inhibit lipogenesis (fat formation) by isolating a region of the growth hormone molecule associated with metabolic effects, while minimizing binding to the growth hormone receptor sites linked to growth-promoting and insulin-related effects. This mechanism was primarily characterized in laboratory and animal studies. When tested in human obesity trials, it did not translate into a demonstrated meaningful reduction in body weight or fat at the exposures studied, indicating that the proposed mechanism did not produce the anticipated clinical result.

What researchers have studied

  • Randomized human trials evaluating weight and fat-related outcomes in individuals with obesity
  • Animal studies of lipolytic and anti-lipogenic activity attributed to the growth hormone fragment region
  • Pharmacokinetic characterization of injectable and oral formulations in early development
  • Safety and tolerability data collected during the completed human obesity trials
  • Comparative discussion of AOD-9604 against full-length growth hormone's metabolic and growth effects

Human evidence

  • AOD-9604 was tested in human clinical trials specifically designed to evaluate obesity-related outcomes, which is more direct human testing than many peptides on this site have received.
  • Those trials did not establish a meaningful weight-loss or fat-loss benefit at the exposures studied, and this negative result is a central, honest fact about the substance rather than a gap awaiting more research.
  • Because the obesity development program did not proceed to approval, there is no larger confirmatory trial data beyond what was already reported.
  • Long-term safety data outside the completed trial programs has not been systematically established.

Preclinical evidence

  • Animal studies describing lipolytic activity attributed to the growth hormone fragment region.
  • Animal studies exploring reduced growth-promoting and insulin-related activity compared with full-length growth hormone.
  • Cell-based metabolic studies characterizing fat cell response to the fragment.

What is not yet known

  • Whether any subgroup, dosing approach, or delivery method could produce a meaningful weight or fat effect has not been established, and the existing negative trial data does not support assuming so.
  • Long-term safety with extended or repeated use in humans outside the completed trial programs is not well characterized.
  • How compounded products described as AOD-9604 vary in composition, purity, and consistency from source to source.
  • Whether the proposed selective metabolic mechanism, without growth-promoting activity, fully holds up under real-world exposure patterns.

Regulatory status and access

AOD-9604 is not an FDA-approved product and its clinical development for obesity did not succeed in establishing meaningful benefit, so any compounded availability should be understood against that history rather than assumed to reflect proven effectiveness. Compounding, where it exists, is never itself an approval. Ask about current availability. Only a physician can determine whether discussing this substance is appropriate after an evaluation.

Known and potential risks

  • Unregulated, grey-market sourcing risk applies since AOD-9604 is not an approved, quality-controlled product.
  • Because the substance did not demonstrate meaningful benefit in the trials that tested it for obesity, using it for weight or fat goals carries a real risk of cost and effort without an evidence-based expectation of benefit.
  • Long-term safety outside the completed clinical trial programs is not well established.
  • Injection site reactions have been described in some study reports.
  • Product quality and identity cannot be verified in compounded or informally sourced material.

Cautions and who may not be a candidate

  • Active malignancy or unresolved oncologic history.
  • Pregnancy or breastfeeding.
  • Undiagnosed weight change or metabolic symptoms that have not been medically evaluated.
  • Reliance on this substance in place of established, evidence-based approaches to weight management.
  • Situations where product identity and sourcing cannot be confirmed.

Questions to discuss with a physician

  • What did the human obesity trials for AOD-9604 actually find, and why did the program not lead to approval?
  • Given that history, what would be the rationale for considering it at all?
  • What evidence-based, established options exist for the goals I actually have?
  • How would product quality and identity be verified if this were ever discussed?
  • What are the realistic expectations, given the negative trial history, if I were to consider it anyway?
  • Are there safety considerations from the completed trials I should know about?

Frequently asked questions

Is AOD-9604 FDA-approved?

No. AOD-9604 is not an FDA-approved drug product. It was studied in human obesity trials that did not establish a meaningful benefit, and no approval followed.

Did AOD-9604 work in human trials?

Human clinical trials conducted specifically to evaluate its effect on obesity did not establish a meaningful weight-loss or fat-loss benefit at the exposures studied. This is a documented negative outcome, not an open question.

Does GOAL.MD sell AOD-9604?

This page is educational content, not an offer of sale. Ask about current availability, and only a physician can determine appropriateness after an evaluation.

What is AOD-9604 supposed to be?

It is a fragment of the human growth hormone molecule, specifically amino acids 176 to 191, engineered to isolate a metabolic region of growth hormone while minimizing growth-promoting and insulin-related effects.

Why do people still discuss AOD-9604 for weight loss if the trials did not show benefit?

It continues to circulate in informal online sources that often omit or understate the negative obesity trial results, which is why this page states that outcome directly.

Is AOD-9604 the same as human growth hormone?

No. It is a small fragment of the growth hormone molecule, not full-length growth hormone, and was specifically designed to exclude growth hormone's growth-promoting activity.

Are there safety concerns with AOD-9604?

Some injection site reactions were reported in study programs, and because it is not an approved product, sourcing and product-quality risks apply to any compounded or informally obtained material.

Is there ongoing research that might change this picture?

Some preclinical and mechanistic research continues in narrower contexts, but this does not undo the documented outcome of the human obesity trials, and any future change in the evidence would need to be verified against new, credible sources.

Who should not consider AOD-9604?

Anyone relying on it in place of established, evidence-based weight management approaches, and anyone with active malignancy, pregnancy or breastfeeding, or undiagnosed symptoms, should not consider it without a full discussion with a physician.

How does AOD-9604 differ from other growth hormone axis peptides on this site?

Unlike substances that remain purely investigational with limited human data, AOD-9604 was specifically tested in human obesity trials, and that testing did not show meaningful benefit, which makes its evidence story a completed negative result rather than an open one.

What is AOD-9604?

AOD-9604 is a synthetically produced fragment corresponding to the C-terminal region (amino acids 176 to 191) of the human growth hormone molecule. It was engineered specifically to isolate the region of growth hormone proposed to be involved in fat metabolism, while attempting to exclude the region responsible for growth-promoting and insulin-resistance effects associated with full-length growth hormone. It has been studied as an injectable and, in some development programs, as an oral formulation, though it is not an approved drug in either form.

Does the legal or regulatory status of AOD-9604 tell me whether it works?

No. Regulatory status describes what may lawfully be made, prescribed, or sold, and it is a separate question from what the research shows. On this page the regulatory description and the evidence tiers are kept apart so neither is mistaken for the other.

Can a licensed U.S. compounding pharmacy prepare AOD-9604?

AOD-9604 is not an FDA-approved product and its clinical development for obesity did not succeed in establishing meaningful benefit, so any compounded availability should be understood against that history rather than assumed to reflect proven effectiveness. Compounding, where it exists, is never itself an approval.

What human evidence exists for AOD-9604?

Human research exists but is early, small, or narrow in scope, so conclusions about general use are premature. AOD-9604 was tested in human clinical trials specifically designed to evaluate obesity-related outcomes, which is more direct human testing than many peptides on this site have received.

What have animal and laboratory studies of AOD-9604 reported?

Animal studies describing lipolytic activity attributed to the growth hormone fragment region; Animal studies exploring reduced growth-promoting and insulin-related activity compared with full-length growth hormone; Cell-based metabolic studies characterizing fat cell response to the fragment. These are animal, tissue, or cell-culture findings. They describe a model, not a demonstrated result in people.

Do the animal findings for AOD-9604 mean it works in people?

No. Findings in animals or in cell culture routinely fail to reproduce in humans, and a positive laboratory model is not evidence of a human benefit. Whether any of this translates to people is exactly what has not been established.

How is AOD-9604 proposed to work?

AOD-9604 was proposed, based on animal and early metabolic research, to stimulate lipolysis (fat breakdown) and inhibit lipogenesis (fat formation) by isolating a region of the growth hormone molecule associated with metabolic effects, while minimizing binding to the growth hormone receptor sites linked to growth-promoting and insulin-related effects. This mechanism was primarily characterized in laboratory and animal studies. This is a proposed pathway rather than a demonstrated effect.

What is AOD-9604 being studied for?

Published work has focused on Randomized human trials evaluating weight and fat-related outcomes in individuals with obesity; Animal studies of lipolytic and anti-lipogenic activity attributed to the growth hormone fragment region; Pharmacokinetic characterization of injectable and oral formulations in early development; Safety and tolerability data collected during the completed human obesity trials. A research focus describes where questions are being asked, not where answers have been found.

What is still unknown about AOD-9604?

Whether any subgroup, dosing approach, or delivery method could produce a meaningful weight or fat effect has not been established, and the existing negative trial data does not support assuming so; Long-term safety with extended or repeated use in humans outside the completed trial programs is not well characterized; How compounded products described as AOD-9604 vary in composition, purity, and consistency from source to source; Whether the proposed selective metabolic mechanism, without growth-promoting activity, fully holds up under real-world exposure patterns.

What are the risks of AOD-9604?

Unregulated, grey-market sourcing risk applies since AOD-9604 is not an approved, quality-controlled product; Because the substance did not demonstrate meaningful benefit in the trials that tested it for obesity, using it for weight or fat goals carries a real risk of cost and effort without an evidence-based expectation of benefit; Long-term safety outside the completed clinical trial programs is not well established.

Is AOD-9604 appropriate during pregnancy or breastfeeding?

No. Pregnancy and breastfeeding are listed as situations where this is not appropriate, because the safety data needed to make that judgement in those populations does not exist.

What would a physician monitor if AOD-9604 were discussed?

Monitoring concepts include Comparison of any considered approach against established, evidence-based weight management options as a baseline discussion point; General metabolic and safety screening consistent with any discussion of growth hormone-related substances; Periodic reassessment of whether newer research has changed the evidence picture described here. These are concepts a clinician would apply, not instructions for self-directed use.

Are products sold online as AOD-9604 verified?

No. Unregulated, grey-market sourcing risk applies since AOD-9604 is not an approved, quality-controlled product. Material bought outside a licensed pharmacy has no verified identity, purity, or sterility.

How would a GOAL.MD physician evaluate a question about AOD-9604?

A physician starts with the problem you are trying to solve, reviews your history and current medications, and says plainly where the evidence stands. Medical appropriateness is determined only after a full evaluation, and for many substances the honest answer is that the evidence does not support use.

What should I ask a physician about AOD-9604?

Useful questions include: What did the human obesity trials for AOD-9604 actually find, and why did the program not lead to approval?; Given that history, what would be the rationale for considering it at all?; What evidence-based, established options exist for the goals I actually have?; How would product quality and identity be verified if this were ever discussed?.

Why do people ask about AOD-9604?

Patients researching growth hormone-related weight loss options sometimes encounter AOD-9604 marketed informally as a 'fat-burning fragment' of growth hormone without full context that it was tested in human obesity trials and did not succeed. Understanding that history directly answers the most common question about it.

Who reviews what GOAL.MD publishes about AOD-9604?

Clinical content is reviewed by a named physician for medical accuracy and by a second physician for regulatory and compliance language before it is published, and a review byline appears only when that review is recorded. New material stays unpublished until both reviews are on record.

This page is educational. Nothing here can be ordered, and nothing here is a prescription or medical advice. Compounded preparations are not FDA-approved. To ask about current availability, visit goal.md/peptides/connect or call or text 314-907-3103.

Medically reviewed by Michael Fitch, MD, MD. Last reviewed 2026-08-13.