If you have been reading about RP-HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Soluble in water | Also soluble in aqueous buffers |
| Storage temperature | -20°C or below | Protect from light and moisture |
| Analytical method | RP-HPLC | Purity and identity assessment |
| Mass confirmation | Mass spectrometry | Verifies molecular mass |
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.
Clinical development of AOD-9604 included trials in people with obesity. Reports from early-phase and mid-phase studies described modest or inconsistent changes in body weight. A phase IIb program did not meet its primary endpoint, and the compound was not approved for medical use. Differences in formulation, delivery route, and participant characteristics may explain some of the variation. Later investigations explored whether the peptide might have effects in other tissues, including cartilage.
Regulatory treatment of AOD-9604 is shaped by its classification as a peptide hormone. The World Anti-Doping Agency lists it as a prohibited substance, and many national anti-doping organizations adopt that list. It does not hold approval as a prescription medicine in the United States, the European Union, or other major markets. Products sold online are frequently labeled for research use only and may not undergo independent quality testing. Import and possession rules differ by country, so legal status depends on local law.
CO2 + 4 H2S + O2 → CH2O + 4 S0 + 3 H2O CO2 + H2S + O2 + H2O → CH2O + SO2–4 + 2 H+ In modern oceans, Thiomicrospira, Halothiobacillus, and Beggiatoa are primary sulfur oxidizing bacteria, and form chemosynthetic symbioses with animal hosts. The host provides metabolic substrates (e.g., CO2, O2, H2O) to the symbiont while the symbiont generates organic carbon for sustaining the metabolic activities of the host. The produced sulfate usually combines with the leached calcium ions to form gypsum, which can form widespread deposits on near mid-ocean spreading centers. Sulfur metabolizing microbes are often engaged in close symbiotic relationships with other microbes, and even animals. PSB and sulfate reducers form microbial aggregates called “pink berries” in the salt marshes of Massachusetts within which sulfur cycling occurs through the direct exchange of sulfur species. The Vestimentiferan tube worms that grow around hydrothermal vents lack a digestive tract but contain specialized organelles called trophosomes within which autotrophic, sulfide oxidizing bacteria are housed. The tube worms provide the bacteria with sulfide and the bacteria shares the fixed carbon with the worms.
StreptomeDB, a directory of Streptomyces isolates, contains over 2400 compounds isolated from more than 1900 strains. Streptomyces hygroscopicus and Streptomyces viridochromeogenes produce the herbicide bialaphos. Expansion of Streptomyces screenings have included endophytes, extremophiles, and marine varieties. A recent screening of TCM extracts revealed a Streptomyces that produces a number of antitubercular pluramycins. Wailupemycins are bio-active pyrones isolated from marine Streptomyces. Mayamycin has been shown to have cytotoxic properties. Germicidin are a group of four compounds that act as autoregulatory inhibitors of spore germination. StreptomeDB Antibiotics and Streptomyces : the future of antibiotic discovery Bioprospecting for Microbial Endophytes and Their Natural Products - 2003
However, a dip appears at 254No, and beyond this the half-lives of even-even nobelium isotopes drop sharply as spontaneous fission becomes the dominant decay mode. For example, the half-life of 256No is almost three seconds, but that of 258No is only 1.2 milliseconds. This shows that at nobelium, the mutual repulsion of protons poses a limit to the region of long-lived nuclei in the actinide series. The even-odd nobelium isotopes mostly continue to have longer half-lives as their mass numbers increase, with a dip in the trend at 257No.
Sources: en.wikipedia.org
=== Spread === E. floccosum can remain viable for long periods of time by producing arthroconidia in skin scales. Arthroconidia are thick-walled spores with higher resistance to drying and heat conditions than mycelium. Arthroconidia formation allows E. floccosum to survive for years in showers, baths, swimming pools, towels, blankets, sheets, shoes and other clothing. The fungus commonly spreads by contact in showers and gym facilities.
== Brand names == Brand names for this formulation of morphine include Avinza, Kadian, MS Contin, MST Continus, Morphagesic, Zomorph, Filnarine, MXL, Malfin, Contalgin, Dolcontin, and DepoDur. MS Contin is a trademark of Purdue Pharma, and is available in the United States and Australia. In the UK, MS Contin is marketed by NAPP Pharmaceuticals as MST Continus. MS Contin is a DEA Schedule II substance in the United States, a Schedule 8 (controlled) drug in Australia and a Schedule 2 CD (Controlled Drug) in the UK. Avinza is made by King Pharmaceuticals and Kadian is made by Actavis Pharmaceuticals. Unlike the MS Contin brand and its generic versions, Kadian and Avinza are designed to be 12- to 24-hour release, not 8- to 12-hour. So instead of 2–3 times a day dosing, it can be 1–2 times. MST Continus and MXL are registered copyright and trademark of Napp Pharmaceuticals and are available in the UK. MXL is a 24-hour release formula designed to be taken once daily. It is available in doses between 30 mg and 200 mg in 30 mg intervals (equating to between 1.25 mg/hour and 8.33 mg/hour). MST Continus is a 12-hour release formula, therefore it is given 2 times per day. It is available in the following doses: 5 mg, 10 mg, 15 mg, 30 mg, 60 mg, 100 mg and 200 mg tablets (equating to between 0.416 mg/hour and 16.67 mg/hour).
=== Removal rate === A drug's removal rate will be determined by the proportion of the drug that is removed from circulation by each organ once the drug has been delivered to the organ by the circulating blood supply. This new concept builds on earlier ideas and it depends on a number of distinct factors:
Sources: en.wikipedia.org
Reversed-phase HPLC is used to assess purity, and mass spectrometry confirms molecular mass. Amino acid analysis can verify composition. These methods are standard for peptide characterization.
Lyophilized powder should be stored at -20°C or lower, protected from light and moisture. Reconstituted solutions are less stable and should be aliquoted to avoid freeze-thaw cycles. Always follow supplier instructions.
Variability in purity, counterion content, and residual solvents is possible. Independent testing and certificates of analysis help verify quality. Microbial contamination can occur if handling is not sterile.
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.