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 2025-12-07. Numbers and descriptions here follow the published literature rather than marketing material.
The compound has been studied as a potential treatment for obesity and related metabolic conditions. Published trials have examined changes in body weight, fat mass, and safety markers over limited durations. Results have been mixed or modest, and no large-scale outcome trials are established. Regulatory agencies in several countries have not approved it as a therapeutic drug. Some commercial products have been marketed outside regulated pharmaceutical channels, which raises questions about quality and claims.
In the scientific literature, AOD-9604 appears in reviews of growth hormone fragments and in discussions of peptide-based metabolic research. Some sources distinguish it from growth hormone itself, while others group it with compounds marketed for weight management. The evidence base is small compared with approved obesity medications. Questions about long-term efficacy and clinical relevance remain open, and independent replication of key findings is limited. Most published reports are early-stage and exploratory.
AOD-9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It is often described as hGH fragment 176-191. Research interest arose because it was designed to isolate possible effects on fat metabolism from other actions of growth hormone. It is not a full growth hormone molecule. Its development history includes early laboratory and animal studies followed by human trials. The peptide has been examined in laboratory, animal, and limited human studies.
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.
Interest in AOD-9604 arose from attempts to separate metabolic effects from growth effects attributed to hGH. Early work explored whether the fragment could influence lipolysis or fat oxidation without promoting growth. Those questions remain partly unresolved because human data are limited and results have varied across studies. The peptide is not a hormone replacement for hGH and is not equivalent to hGH in clinical use. Its research history includes both laboratory studies and commercial marketing claims that are not the same as regulatory approval.
| Property | Value | Notes |
|---|---|---|
| Common synonym | hGH fragment 176-191 | Refers to the C-terminal segment |
| Appearance | White to off-white powder | Typically supplied lyophilized |
| Solubility | Soluble in water and aqueous buffers | Confirm with technical data |
| Typical storage temperature | -20 °C for dry powder | Protect from moisture and light |
| Common analytical method | RP-HPLC with UV detection | Often paired with mass spectrometry |
The peptide is frequently described as a growth hormone fragment, although it is chemically distinct from full-length hGH. AOD-9604 contains 16 amino acids and includes two cysteine residues that can form an intramolecular disulfide bond. In solution, this structural feature can influence folding, aggregation, and stability. Published descriptions sometimes call it hGH 176-191 or AOD9604, with spacing and capitalization varying. Such naming differences can complicate literature searches, database entries, and product verification.
Researchers have studied the fragment in cell and animal models to understand its metabolic actions. Some experiments report effects on fat breakdown and fat storage pathways, but the underlying mechanism remains incompletely defined. AOD-9604 does not appear to stimulate the same broad growth hormone receptor signaling as full-length hGH. Whether its observed activities arise from direct receptor interactions or downstream metabolic changes is an open question. Results from different assays are not always consistent.
AOD-9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It corresponds to residues 176-191 of the 191-amino-acid hGH sequence. The fragment is not the full hormone and lacks the receptor-binding region associated with growth and metabolic effects of hGH. Researchers developed it to isolate a specific portion of hGH for study. Its exact sequence and length are often stated in peptide catalogs and patents.
Quality control for AOD-9604 involves verifying identity, purity, and concentration. Suppliers may provide a certificate of analysis listing HPLC purity and mass spectrometry data. Independent verification is advised because peptide products can vary in quality. Researchers should check for counterions, residual solvents, and microbial contamination. Proper documentation supports reproducibility and safety in laboratory studies. When sourcing, institutions often require third-party testing and detailed chain-of-custody records. These steps help ensure that experimental results are attributable to the peptide rather than impurities.
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 drew attention in the 1990s and 2000s as a potential anti-obesity agent. Early work explored both injectable and oral routes, which is unusual for a peptide of this size. Animal studies reported changes in fat metabolism without the growth-promoting or insulin-like effects associated with full-length growth hormone. Subsequent human trials produced mixed or modest results, and the compound did not obtain regulatory approval for weight management in major markets. It remains known mainly through research literature, sports anti-doping listings, and non-approved supplement advertising.
AOD-9604 is prohibited in sport by the World Anti-Doping Agency under the peptide hormone class. Its presence in a sample can be detected through mass spectrometry-based methods, although the exact assay depends on the laboratory. In research settings, material is often supplied as a lyophilized powder for reconstitution. Buyers and researchers should note that products labeled AOD-9604 may vary in purity and actual peptide content. Analytical certificates and independent testing are common ways to verify identity, but no global harmonized standard exists for all commercial lots.
=== Economic return === In 2000, the Joint Economic Committee of Congress reported NIH research, which was funded at $16 billion a year in 2000, that some econometric studies had given a rate of return of 25 to 40 percent per year by reducing the economic cost of illness in the US. It found that of the 21 drugs with the highest therapeutic impact on society introduced between 1965 and 1992, public funding was "instrumental" for 15. As of 2011, NIH-supported research helped to discover 153 new FDA-approved drugs, vaccines, and new indications for drugs in the 40 years prior. One study found NIH funding aided either directly or indirectly in developing the drugs or drug targets for all of the 210 FDA-approved drugs from 2010 to 2016. In 2015, Pierre Azoulay et al. estimated $10 million invested in research generated two to three new patents.
B&O Supprettes is the brand name for a prescription medication containing powdered opium and belladonna alkaloids in a suppository form. They are indicated for the treatment of moderate to severe pain from urethral spasm, and for extending the interval(s) between injections of opiates. The drug has various "off label" uses, including renal colic, intestinal cramps, tenesmus and diarrhea. They are also often prescribed after urinary bladder surgery. B&O Supprettes was unique in the United States because they were the only drug containing opium that is for suppository use sold in the US and, in fact, one of the very few medications that contains opium in any form in the US along with paregoric and opium tincture (laudanum).
Neuromuscular drugs are chemical agents that are used to alter the transmission of nerve impulses to muscles, causing effects such as temporary paralysis of targeted skeletal muscles. Most neuromuscular drugs are available as quaternary ammonium compounds which are derived from acetylcholine (ACh). This allows neuromuscular drugs to act on multiple sites at neuromuscular junctions, mainly as antagonists or agonists of post-junctional nicotinic receptors. Neuromuscular drugs are classified into four main groups, depolarizing neuromuscular blockers, non-depolarizing neuromuscular blockers, acetylcholinesterase inhibitors, and butyrylcholinesterase inhibitors. Clinically, neuromuscular drugs are used in anesthesia to cause paralysis of targeted skeletal muscles. It is most commonly applied in endotracheal intubation by reducing the incidence of hoarseness in vocal cords and esophageal injuries. It is also applied to improve surgical operating conditions by aiding mechanical ventilation in patients with lowered lung compliance. Other than surgical indications, neuromuscular drugs can also be indicated for the use of Alzheimer's disease, Parkinson's disease, etc. Common adverse effects of neuromuscular drugs include abnormal heart rate, blood pressure, and cardiac output.
Sources: en.wikipedia.org
F−H···F− (161.5 kJ/mol (38.6 kcal/mol)), illustrated uniquely by HF2- O−H···N (29 kJ/mol (6.9 kcal/mol)), illustrated water-ammonia O−H···O (21 kJ/mol (5.0 kcal/mol)), illustrated water-water, alcohol-alcohol N−H···N (13 kJ/mol (3.1 kcal/mol)), illustrated by ammonia-ammonia N−H···O (8 kJ/mol (1.9 kcal/mol)), illustrated water-amide OH+3···OH2 (18 kJ/mol (4.3 kcal/mol)) The strength of intermolecular hydrogen bonds is most often evaluated by measurements of equilibria between molecules containing donor and/or acceptor units, most often in solution. The strength of intramolecular hydrogen bonds can be studied with equilibria between conformers with and without hydrogen bonds. The most important method for the identification of hydrogen bonds also in complicated molecules is crystallography, sometimes also NMR-spectroscopy. Structural details, in particular distances between donor and acceptor which are smaller than the sum of the van der Waals radii can be taken as indication of the hydrogen bond strength. One scheme gives the following somewhat arbitrary classification: those that are 63 to 167 kJ/mol (15 to 40 kcal/mol), 21 to 63 kJ/mol (5 to 15 kcal/mol), and 0 to 21 kJ/mol (0 to 5 kcal/mol) are considered strong, moderate, and weak, respectively. Hydrogen bonds involving C−H bonds are both very rare and weak.
Mild to moderate hyperglycemia (typically 130–250 mg/dL, or 7–14 mmol/L) discovered before 25 years of age. However, anyone under 50 can develop MODY. A first-degree relative with a similar degree of diabetes. Absence of positive antibodies or other autoimmunity (e.g., thyroiditis) in patient and family. However, Urbanova et al. found that about one quarter of Central European MODY patients are positive for islet cell autoantibodies (GABA and IA2A). Their expression is transient but highly prevalent. The autoantibodies were found in patients with delayed diabetes onset, and in times of insufficient diabetes control. The islet cell autoantibodies are absent in MODY in at least some populations (Japanese, Britons). Persistence of a low insulin requirement (e.g., less than 0.5 u/kg/day) past the usual "honeymoon" period. Normal insulin levels (e.g. 2.6-24.9) Absence of obesity (although overweight or obese people can get MODY) or other problems associated with type 2 diabetes or metabolic syndrome (e.g., hypertension, hyperlipidemia, polycystic ovary syndrome). Insulin resistance very rarely happens. Cystic kidney disease in patient or close relatives. Non-transient neonatal diabetes, or apparent type 1 diabetes with onset before six months of age. Liver adenoma or hepatocellular carcinoma in MODY type 3 Renal cysts, rudimentary or bicornuate uterus, vaginal aplasia, absence of the vas deferens, epidymal cysts in MODY type 5 The diagnosis of MODY is confirmed by specific gene testing available through commercial laboratories.
In the cobalamins, cobalt normally exists in the trivalent state, Co(III). However, under reducing conditions, the cobalt center is reduced to Co(II) or even Co(I), which are usually denoted as B12r and B12s, for reduced and super reduced respectively. B12r and B12s can be prepared from cyanocobalamin by controlled potential reduction, or chemical reduction using sodium borohydride in alkaline solution, zinc in acetic acid, or by the action of thiols. Both B12r and B12s are stable indefinitely under oxygen-free conditions. B12r appears orange-brown in solution, while B12s appears bluish-green under natural daylight, and purple under artificial light. B12s is one of the most nucleophilic species known in aqueous solution. This property allows the convenient preparation of cobalamin analogs with different substituents, via nucleophilic attack on alkyl halides and vinyl halides. For example, cyanocobalamin can be converted to its analog cobalamins via reduction to B12s, followed by the addition of the corresponding alkyl halides, acyl halides, alkene or alkyne. Steric hindrance is the major limiting factor in the synthesis of the B12 coenzyme analogs. For example, no reaction occurs between neopentyl chloride and B12s, whereas the secondary alkyl halide analogs are too unstable to be isolated. This effect may be due to the strong coordination between benzimidazole and the central cobalt atom, pulling it down into the plane of the corrin ring. The trans effect determines the polarizability of the Co–C bond so formed.
==== Hypogonadism ==== Insufficient or low levels of testosterone in the body can affect the proper functioning of the male reproductive structures and thus lead to decreased secretions or hypospermia. Long-term exposure to drugs with anti-androgen properties (e.g. spironolactone) can also lead to infertility or low volume of semen. Testosterone is produced by the testes and can be used to diagnose hypogonadism.
Sources: en.wikipedia.org
It is a synthetic peptide fragment derived from the C-terminal region of human growth hormone, commonly referred to as hGH fragment 176-191. It has been investigated for effects on fat metabolism, but it is not an approved medication in most jurisdictions.
No. It is a shortened peptide fragment, not the full hormone. It does not contain the entire hGH sequence and is studied for different proposed effects.
Regulatory approvals for weight loss are not established in major jurisdictions. Some human trials reported modest changes, but the evidence is limited, and it remains a research compound.
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.