What Is AOD-9604? Uses, Benefits, Safety, FDA Status, and Evidence
Medical review note: This article is for educational purposes only and does not provide medical advice. AOD-9604 is not FDA-approved for human therapeutic use. Products sold online as AOD-9604, hGH fragment 176-191, hGH fragment 177-191, or “research use only” AOD-9604 may carry serious safety, quality, and legal risks.
Quick answer
AOD-9604 is a modified peptide fragment derived from the C-terminal region of human growth hormone. It is often described as hGH fragment 176-191 or hGH fragment 177-191 and was developed to study whether the fat-metabolism effects of growth hormone could be separated from growth-promoting and glucose-related effects. Animal studies suggested effects on fat oxidation and weight gain, but human weight-loss evidence is weak and disappointing. AOD-9604 is not FDA-approved, FDA says compounded drugs containing AOD-9604 may pose immunogenicity and peptide-characterization risks, and WADA prohibits AOD-9604 in competitive sport.
Key facts about AOD-9604
| Question | Answer |
|---|---|
| What is AOD-9604? | A modified fragment of human growth hormone studied for fat metabolism and obesity. |
| Other names | hGH fragment 176-191, hGH fragment 177-191, Tyr-hGH 177-191, anti-obesity drug 9604. |
| Peptide class | Human growth hormone fragment / lipolytic peptide fragment. |
| Main mechanism | Proposed effects on fat oxidation, lipolysis, and lipid metabolism without the full growth-promoting effects of growth hormone. |
| FDA-approved? | No. AOD-9604 is not an FDA-approved drug. |
| Main studied uses | Obesity, fat metabolism, weight loss, lipolysis, and metabolic research. |
| Human evidence level | Weak. Human clinical evidence does not strongly support meaningful weight-loss efficacy. |
| Animal/lab evidence level | Preclinical studies suggest effects on fat metabolism and weight gain in animal models. |
| Common online claims | “Fat-burning peptide,” “weight-loss peptide,” “belly-fat peptide,” “metabolism booster,” “body recomposition,” “safe HGH fragment.” |
| Sports status | Prohibited by WADA under S0 non-approved substances and growth hormone fragment-related language. |
| Main safety concern | Not FDA-approved, weak human efficacy evidence, FDA-identified immunogenicity and peptide-characterization concerns, and risks from unapproved online products. |
What is AOD-9604?
AOD-9604 is a modified peptide fragment derived from human growth hormone. It is commonly described as corresponding to the C-terminal portion of human growth hormone, especially hGH fragment 176-191 or 177-191, with modifications intended to preserve fat-metabolism effects while avoiding some of the broader effects of full-length growth hormone.
AOD-9604 was developed as an obesity-drug candidate. Early research focused on whether this fragment could stimulate fat breakdown and fat oxidation without causing the growth-promoting or glucose-worsening effects associated with full human growth hormone.
A PubMed-indexed animal study reported that both human growth hormone and AOD-9604 reduced body weight and body fat in obese mice after chronic administration. Another PubMed-indexed study reported that human growth hormone and its C-terminal fragment reduced weight gain, increased fat oxidation, and stimulated lipolysis in obese mice.
The key distinction:
AOD-9604 has interesting animal and metabolic research, but that does not mean it is a proven human weight-loss medication.
How does AOD-9604 work?
AOD-9604 was designed around the idea that part of human growth hormone may influence fat metabolism.
Proposed mechanisms include:
- Increased lipolysis
- Increased fat oxidation
- Reduced lipogenesis
- Effects on adipose tissue metabolism
- Possible beta-adrenergic pathway involvement
- Attempted separation of fat-metabolism effects from full growth hormone effects
A PubMed-indexed paper on AOD-9604 and human growth hormone fragments describes how AOD-9604 was studied in relation to body weight and body fat reduction in obese mice. A separate PubMed-indexed study reported that AOD-9604 increased fat oxidation and stimulated lipolysis in obese mice.
But mechanism is not proof.
A proposed fat-metabolism mechanism does not prove that AOD-9604 produces meaningful weight loss in humans, reduces belly fat, improves body composition, or safely works as a consumer fat-loss peptide. The quality of evidence depends on controlled human studies, not animal models or vendor claims.
What is AOD-9604 used for?
AOD-9604 is commonly discussed for fat loss, weight loss, body recomposition, belly-fat reduction, and metabolic optimization. These uses differ sharply in evidence quality.
| Use | Evidence level | What is known | What is not known |
|---|---|---|---|
| Weight loss in humans | Weak / disappointing | Human trial summaries report modest or inconsistent weight-loss effects. | It is not FDA-approved and is not proven as an effective obesity medication. |
| Fat oxidation | Preclinical | Animal studies suggest effects on fat oxidation and lipolysis. | Human clinical relevance is uncertain. |
| Belly-fat reduction | Unsupported as a specific claim | Online marketing often targets “belly fat.” | Strong human evidence for targeted abdominal fat loss is lacking. |
| Body recomposition | Weak / extrapolated | Claims are usually inferred from fat-metabolism theory. | Strong controlled human outcome evidence is lacking. |
| Obesity treatment | Not established | AOD-9604 was investigated as an obesity candidate. | It did not become an approved obesity drug. |
| Growth hormone alternative | Misleading | It is a growth hormone fragment, not full growth hormone. | It should not be treated as a safe or proven substitute for HGH therapy. |
| Athletic performance | Unsupported and prohibited | Some athletes have sought it for body composition. | WADA prohibits AOD-9604. |
| Online research-use AOD-9604 | High uncertainty | Sellers market it as a peptide product. | Quality, sterility, identity, concentration, and legality may be unknown. |
What does the research show?
Human evidence
The human evidence for AOD-9604 is not strong.
A review article in Obesity Pharmacotherapy summarized a 12-week randomized clinical trial in which subjects receiving AOD-9604 lost an average of 2.6 kg, compared with 0.8 kg in the placebo group. That sounds interesting, but the broader clinical development story is not strong enough to support AOD-9604 as a proven obesity drug.
The practical interpretation:
AOD-9604 has some human clinical history, but it has not produced the kind of strong, repeatable, approval-level evidence seen with modern obesity drugs like semaglutide or tirzepatide.
Animal and laboratory evidence
The preclinical evidence is more favorable than the human evidence.
A PubMed-indexed study found that AOD-9604 reduced body weight and body fat in obese mice after chronic administration. Another PubMed-indexed study reported that human growth hormone and its C-terminal fragment reduced weight gain and increased fat oxidation in obese mice.
An earlier PubMed-indexed oral fragment study studied AOD-related synthetic fragments of growth hormone and lipid metabolism in animal models.
The practical interpretation:
AOD-9604 looks more compelling in animal fat-metabolism models than in human clinical weight-loss evidence.
FDA safety context
The FDA has flagged AOD-9604 in the compounding-risk context.
The FDA page on bulk drug substances that may present significant safety risks states that compounded drugs containing AOD-9604 may pose significant risk for immunogenicity for certain routes of administration and may have complexities related to peptide impurities and active pharmaceutical ingredient characterization.
The practical interpretation:
AOD-9604 should not be treated as a harmless fat-loss peptide. FDA has identified safety and quality concerns for compounded AOD-9604.
Evidence summary
| Claim | Evidence verdict | Explanation |
|---|---|---|
| “AOD-9604 is a human growth hormone fragment.” | Supported | It is commonly described as a modified C-terminal fragment of human growth hormone. |
| “AOD-9604 increases fat oxidation in animals.” | Supported preclinically | Animal studies suggest effects on fat oxidation, lipolysis, and body-fat outcomes. |
| “AOD-9604 causes meaningful human weight loss.” | Weak / not established | Human evidence is limited and not strong enough for FDA approval. |
| “AOD-9604 is FDA-approved.” | False | AOD-9604 is not FDA-approved. |
| “AOD-9604 is the same as HGH.” | False | AOD-9604 is a fragment, not full-length recombinant human growth hormone. |
| “AOD-9604 is a safe fat burner.” | Not established | FDA flags compounded AOD-9604 for immunogenicity and peptide-characterization concerns. |
| “AOD-9604 targets belly fat.” | Unsupported | Targeted belly-fat claims are marketing claims, not established clinical evidence. |
| “AOD-9604 is allowed for athletes.” | False | WADA has stated AOD-9604 is prohibited. |
| “Research-use AOD-9604 is clinically proven.” | False | Research-use products are not FDA-approved consumer therapeutic products. |
Is AOD-9604 FDA-approved?
No. AOD-9604 is not FDA-approved.
The FDA compounding safety-risk page states that compounded drugs containing AOD-9604 may pose significant immunogenicity risk for certain routes of administration and may have complexities related to peptide impurities and API characterization.
The FDA AOD-9604 acetate document discusses AOD-9604 acetate in the context of pharmacy compounding review and safety, effectiveness, historical use, and characterization considerations.
The key distinction:
AOD-9604 is a biologically active investigational peptide fragment, not an FDA-approved prescription medication.
Is AOD-9604 legal?
AOD-9604’s legal status depends on product type, intended use, and jurisdiction, but the practical answer is simple:
AOD-9604 is not an FDA-approved drug, and online availability does not mean it is legally marketed for human therapeutic use.
Some sellers market AOD-9604 as a research peptide. That does not make it safe, approved, legal, or appropriate for consumer use.
The blunt version:
Buying “research use only” AOD-9604 from an online seller is not the same as receiving an FDA-approved prescription medication from a legitimate pharmacy.
Is AOD-9604 banned in sports?
Yes. AOD-9604 is prohibited in competitive sport.
The WADA statement on AOD-9604 states that AOD-9604 is still under preclinical and clinical development, has not been approved for therapeutic use by any government health authority, and falls under the S0 category of the prohibited list.
The WADA Prohibited List also includes growth hormone fragments, with examples including AOD-9604 and hGH 176-191.
For athletes, the answer is simple:
Do not use AOD-9604 if you are subject to anti-doping rules.
Safety and side effects
AOD-9604 should not be treated as a harmless supplement.
Possible or theoretical concerns include:
- Immunogenicity risk
- Peptide-related impurities
- API characterization issues
- Sterility risk
- Dosing variability
- Mislabeling
- Injection-site reactions
- Unknown long-term safety
- Product-quality risk from online sellers
- Anti-doping consequences for athletes
FDA specifically flags compounded AOD-9604 for potential immunogenicity risk and peptide-related impurity and characterization complexity.
A serious evaluation of AOD-9604 should separate controlled research from online peptide products.
AOD-9604 vs similar peptides and drugs
| Compound | Category | Main difference |
|---|---|---|
| AOD-9604 | Human growth hormone fragment | Investigated for fat metabolism; not FDA-approved and prohibited in sport. |
| hGH fragment 176-191 | Growth hormone fragment | Closely related naming used online; often discussed in fat-loss peptide markets. |
| Human growth hormone | Recombinant hormone | Full-length hormone with broader growth and metabolic effects; different from AOD-9604. |
| Tesamorelin | GHRH analog | FDA-approved for excess abdominal fat in adults with HIV and lipodystrophy. |
| Sermorelin | GHRH analog | Historically FDA-approved as Geref, now discontinued. |
| CJC-1295 | GHRH analog | Growth hormone-releasing hormone analog, not a growth hormone fragment. |
| Semaglutide | GLP-1 receptor agonist | FDA-approved metabolic drug for diabetes and weight-related indications. |
| Tirzepatide | Dual GIP/GLP-1 receptor agonist | FDA-approved metabolic drug for diabetes and weight-related indications. |
The key distinction:
AOD-9604 belongs in the growth hormone fragment category. It is not a GLP-1 medication, GHRH analog, repair peptide, or FDA-approved obesity drug.
Why is AOD-9604 sold as “research use only”?
Some online sellers use “research use only” language to sell AOD-9604 outside normal prescription-drug channels.
That label is not a trust signal.
A serious reader should understand this distinction:
| Product type | What it means |
|---|---|
| Clinical-study AOD-9604 | Controlled investigational product used under research conditions. |
| FDA-approved AOD-9604 | Does not currently exist. |
| Compounded AOD-9604 | FDA has raised immunogenicity and characterization concerns. |
| Research-use AOD-9604 | Not an FDA-approved consumer therapeutic product. |
| Online peptide AOD-9604 | Higher risk for identity, sterility, dosing, and quality problems. |
How to evaluate AOD-9604 claims online
| Claim | What to verify |
|---|---|
| “FDA-approved AOD-9604” | False. AOD-9604 is not FDA-approved. |
| “Clinically proven fat-loss peptide” | Check whether the evidence is human clinical outcome data or animal fat-metabolism data. |
| “Targets belly fat” | Look for controlled human regional-fat studies, not marketing language. |
| “Same as HGH but safer” | Misleading. It is a growth hormone fragment, not full HGH, and safety is not established for consumer use. |
| “No side effects” | False. FDA flags immunogenicity and peptide-quality concerns. |
| “Research use only” | This does not mean safe, legal, approved, or appropriate for human use. |
| “Safe for athletes” | False. WADA prohibits AOD-9604. |
| “Third-party tested” | Ask for batch-specific HPLC, LC-MS, identity, purity, sterility, endotoxin, aggregate, and impurity data. |
Bottom line
AOD-9604 is a modified fragment of human growth hormone investigated for fat metabolism and obesity. Animal studies suggest it can affect fat oxidation and weight gain, but human evidence for meaningful weight loss is weak, and AOD-9604 never became an FDA-approved obesity medication.
The most defensible conclusion is:
AOD-9604 is biologically interesting but clinically weak as a weight-loss peptide. It is not FDA-approved, FDA has identified safety and quality concerns for compounded AOD-9604, and athletes should avoid it because WADA prohibits AOD-9604 in sport.
FAQ
What is AOD-9604?
AOD-9604 is a modified fragment of human growth hormone, commonly described as hGH fragment 176-191 or 177-191, that was studied for fat metabolism and obesity.
What does AOD-9604 do?
AOD-9604 was designed to study whether part of human growth hormone could influence fat oxidation and lipolysis without the full effects of growth hormone. Animal studies suggested fat-metabolism effects, but human weight-loss evidence is weak.
Is AOD-9604 FDA-approved?
No. AOD-9604 is not FDA-approved. FDA has flagged compounded AOD-9604 for immunogenicity, peptide impurity, and API characterization concerns.
Is AOD-9604 the same as HGH?
No. AOD-9604 is a fragment derived from human growth hormone, not full-length recombinant human growth hormone.
Is AOD-9604 the same as hGH fragment 176-191?
AOD-9604 is commonly described as a modified fragment of the C-terminal region of human growth hormone and is closely associated with hGH fragment 176-191 or 177-191 terminology.
Does AOD-9604 work for weight loss?
The evidence is weak. Animal studies suggested fat-metabolism effects, but human evidence has not established AOD-9604 as an effective FDA-approved weight-loss medication.
Does AOD-9604 burn belly fat?
Targeted belly-fat claims are not established by strong human clinical evidence. This is mostly marketing language.
Is AOD-9604 safe?
AOD-9604 does not have enough strong human safety and efficacy data to treat it as safe for consumer therapeutic use. FDA has raised concerns about immunogenicity and peptide-related impurities in compounded products.
Is AOD-9604 legal?
AOD-9604 is not an FDA-approved drug. Online sales as a research peptide do not mean it is legally marketed for human therapeutic use.
Is AOD-9604 banned in sports?
Yes. WADA has stated that AOD-9604 is prohibited under S0 non-approved substances, and WADA lists growth hormone fragments including AOD-9604 and hGH 176-191.
Why do sellers call AOD-9604 “research use only”?
Sellers often use “research use only” language because AOD-9604 is not FDA-approved for consumer therapeutic use. The phrase does not make the product safe, legal, approved, or clinically proven.
What is the biggest risk with AOD-9604?
The biggest risks are using an unapproved peptide with weak human efficacy evidence, relying on animal data as if it proves human fat loss, and buying online products with uncertain identity, purity, sterility, concentration, and safety.
Sources
- FDA: Certain Bulk Drug Substances for Use in Compounding May Present Significant Safety Risks
- FDA: AOD-9604 Acetate Compounding Review Document
- WADA: Statement on AOD-9604
- WADA: Prohibited List
- WADA: 2025 Prohibited List
- PubMed: Effects of human GH and AOD-9604 in obese mice
- PubMed: Increase of fat oxidation and weight loss in obese mice
- PubMed: Effects of oral administration of a synthetic fragment of human growth hormone
- PMC: Obesity Pharmacotherapy, Current Perspectives and Future Directions
- Reuters: FDA expected to revisit restrictions on compounded peptides
Frequently asked questions
What is AOD-9604?
AOD-9604 is a modified fragment of human growth hormone, commonly described as hGH fragment 176-191 or 177-191, that was studied for fat metabolism and obesity.
Is AOD-9604 FDA-approved?
No. AOD-9604 is not FDA-approved. FDA has flagged compounded AOD-9604 for immunogenicity, peptide impurity, and API characterization concerns.
Is AOD-9604 the same as HGH?
No. AOD-9604 is a fragment derived from human growth hormone, not full-length recombinant human growth hormone.
Does AOD-9604 work for weight loss?
The evidence is weak. Animal studies suggested fat-metabolism effects, but human evidence has not established AOD-9604 as an effective FDA-approved weight-loss medication.
Is AOD-9604 safe?
AOD-9604 does not have enough strong human safety and efficacy data to treat it as safe for consumer therapeutic use. FDA has raised concerns about immunogenicity and peptide-related impurities in compounded products.
Is AOD-9604 banned in sports?
Yes. WADA has stated that AOD-9604 is prohibited under S0 non-approved substances, and WADA lists growth hormone fragments including AOD-9604 and hGH 176-191.
Sources
- [1]
- [2]
- [3]WADA: Statement on AOD-9604
Anti Doping
- [4]WADA: Prohibited List
Anti Doping
- [5]WADA: 2025 Prohibited List
Anti Doping
- [6]
- [7]
- [8]
- [9]
- [10]
Last updated May 9, 2026