A practical reference on RP-HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-27 and is reviewed periodically as new material appears.
AOD-9604 is listed as a prohibited substance in sport by the World Anti-Doping Agency. It falls under the peptide hormones, growth factors, related substances, and mimetics class on the prohibited list. Anti-doping organizations treat its presence in an athlete's sample as an adverse finding unless a therapeutic use exemption applies. The prohibition reflects concerns about performance enhancement in competitive settings and the difficulty of distinguishing exogenous peptide use from endogenous hormone fragments.
Detection of AOD-9604 in biological samples relies on analytical techniques capable of distinguishing a small synthetic peptide from related endogenous sequences. Liquid chromatography coupled with tandem mass spectrometry is commonly used for confirmatory analysis. Sample preparation may involve immunoaffinity enrichment or solid-phase extraction to concentrate the peptide. Because the molecule is small and may be present at low concentrations, assay sensitivity and specificity are ongoing analytical challenges. Laboratories also validate methods against reference materials when available.
AOD-9604 is a synthetic peptide whose structure corresponds to a C-terminal segment of human growth hormone. It is often described as hGH fragment 176-191, a 16-amino-acid sequence. The peptide was designed to isolate a region of hGH associated with fat metabolism while avoiding the full hormone's growth-promoting actions. Laboratory and commercial materials typically present it as a lyophilized powder for research use. Its identity is defined by amino acid sequence, not by a single brand.
The fragment includes residues that can form an internal disulfide bond between two cysteine positions. This structural feature can influence how the peptide folds and how stable it is in solution. AOD-9604 differs from full-length hGH in size and receptor interactions; it does not contain the entire growth hormone sequence. Published descriptions sometimes use slightly different residue numbering, so sequence information should be checked against primary sources. The molecule is small compared with intact hGH, which affects analytical detection and purification approaches.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport | Listed by WADA under peptide hormones |
| WADA class | S2 | Peptide hormones, growth factors, related substances, and mimetics |
| Approved therapeutic use | Not established | Clinical research did not lead to broad marketing approval |
| Common detection method | LC-MS/MS | Liquid chromatography-tandem mass spectrometry |
| Sample preparation | Extraction and enrichment | Immunoaffinity or solid-phase extraction may be used |
Analytical characterization of AOD-9604 typically employs reversed-phase high-performance liquid chromatography (RP-HPLC) to assess purity and identity. Mass spectrometry provides confirmation of molecular mass, while amino acid analysis can verify composition. These methods are standard for peptide research chemicals. Because the peptide lacks a distinct chromophore, detection often relies on ultraviolet absorbance at 214 nm or mass spectrometric response. Laboratories may also use capillary electrophoresis for separation. For example, size-exclusion chromatography can detect aggregates.
Stability of AOD-9604 depends on storage conditions. Lyophilized powder is generally more stable than reconstituted solution. Recommended storage is typically at -20°C or lower, protected from light and moisture. Repeated freeze-thaw cycles can cause aggregation or degradation. In solution, the peptide may be susceptible to hydrolysis or oxidation, so aliquoting and cold storage are common practices. Researchers often add stabilizers such as mannitol or trehalose during lyophilization to improve shelf life.
Identity and purity are usually assessed with reversed-phase high-performance liquid chromatography and mass spectrometry. Reversed-phase HPLC separates the peptide from related impurities and can estimate purity by ultraviolet absorbance, while mass spectrometry confirms the molecular mass and detects modifications. Peptide mapping, amino acid analysis, and disulfide mapping may be used when the sequence or disulfide arrangement must be verified. Because AOD9604 contains cysteine residues, oxidation and disulfide isomers are possible quality concerns in synthetic batches.
Quality varies among research-grade suppliers, so certificates of analysis and independent testing are important for verification. A typical certificate reports purity by HPLC, identity by mass spectrometry, appearance, and sometimes residual solvents or water content. AOD9604 is often sold as a research chemical not intended for human consumption, and labels can be inaccurate. Common misconceptions include treating the peptide as a form of growth hormone, assuming supplement status, or expecting approved-drug quality from unregulated products.
== Adverse effects == The US prescription label includes a boxed warning for allergic reactions including anaphylaxis. The most common side effects include upper respiratory tract infection, ear infection, fever, anemia, cough, vomiting, diarrhea, rash, COVID-19, runny nose, nasal congestion, fall, headache, skin abrasion, and hives.
=== Law Society review === In December 2005, the Law Society revealed that it has set up a committee, named Review Committee on Capital Punishment, to examine capital punishment in the country. The president of the society, Senior Counsel Philip Jeyaretnam, said that the main focus of the review was on issues regarding administering the death penalty such as whether it should be mandatory. A report of the review would be submitted to the Ministry of Law. On 6 November 2006, they were invited to give its views on proposed amendments to the Penal Code to the Ministry of Home Affairs. In their report, issued on 30 March 2007, they argued against the mandatory death penalty:
== Salaries == According to the 2022 Medscape Physician Compensation Report, physicians on average earn $339K annually. Primary care physicians earn $260K annually while specialists earned $368K annually. The table below details the average range of salaries for physicians in the US of medical specialties:
Sources: en.wikipedia.org
== Morphology and histological staining == Hematoxylin and eosin staining (H&E) shows that the cytoplasm of active osteoblasts is slightly basophilic due to the substantial presence of rough endoplasmic reticulum. The active osteoblast produces substantial collagen type I. About 10% of the bone matrix is collagen with the balance mineral. The osteoblast's nucleus is spherical and large. An active osteoblast is characterized morphologically by a prominent Golgi apparatus that appears histologically as a clear zone adjacent to the nucleus. The products of the cell are mostly for transport into the osteoid, the non-mineralized matrix. Active osteoblasts can be labeled by antibodies to Type-I collagen, or using naphthol phosphate and the diazonium dye fast blue to demonstrate alkaline phosphatase enzyme activity directly.
== Further reading == William P. Kirk "Krypton 85: a Review of the Literature and an Analysis of Radiation Hazards", Environmental Protection Agency, Office of Research and Monitoring, Washington (1972)
"What we know about the US-Israeli attack on Iran and Tehran's retaliation". CNN. 28 February 2026. Retrieved 28 February 2026. U.S. and Israeli Strikes on Iran, C-SPAN Tracking of traffic in the Strait of Hormuz
Sources: en.wikipedia.org
Yes, the World Anti-Doping Agency classifies AOD-9604 as a prohibited peptide hormone and related substance. Its use by athletes is banned under the relevant anti-doping code.
Confirmatory detection typically uses liquid chromatography with mass spectrometry. Immunoassays may be used for screening, but mass spectrometry provides structural confirmation.
No widely approved therapeutic indication exists for AOD-9604. It has been investigated in clinical studies, but regulatory approvals for general medical use are not established.
It is a synthetic peptide based on a C-terminal fragment of human growth hormone. It is commonly referred to as hGH fragment 176-191 and is studied for metabolic effects rather than growth effects.