AOD 9604 is a synthetic C-terminal fragment of human growth hormone evaluated in preclinical laboratories for its selective lipolytic properties. This technical document provides researchers with an in-depth review of the compound's molecular structure, documented metabolic pathways, standard reconstitution protocols, and criteria for analytical supplier validation.
AOD 9604 is a synthetic C-terminal fragment of human growth hormone evaluated in preclinical laboratories for its selective lipolytic properties. This technical document provides researchers with an in-depth review of the compound's molecular structure, documented metabolic pathways, standard reconstitution protocols, and criteria for analytical supplier validation.
AOD 9604 metabolic research focuses on the C-terminal peptide fragment (Tyr-hGH177-191) derived from human growth hormone. Preclinical studies indicate that AOD 9604 stimulates lipolysis and inhibits lipogenesis in isolated adipocytes and animal models without stimulating IGF-1 secretion, altering blood glucose homeostasis, or inducing systemic growth hormone receptor signaling.
In cell culture and rodent models, this 16-amino-acid peptide activates beta-3 adrenergic receptors, upregulates hormone-sensitive lipase (HSL), and modulates lipid metabolism pathways. Unlike intact somatotropin, AOD 9604 operates via a distinct sequence-specific conformational mechanism that isolates lipid mobilization from anabolic endocrine axes, making it a valuable candidate for metabolic assay design.
AOD 9604 (Advanced Obesity Drug 9604) is a hexadecapeptide representing the modified amino acid sequence 177–191 of human growth hormone (hGH), stabilized by an additional tyrosine residue at the N-terminal position. Its primary primary sequence is Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe, featuring an intramolecular disulfide bridge between Cys7 and Cys14 (corresponding to Cys182 and Cys189 of intact hGH).
This intrachain disulfide linkage maintains a functional cyclic domain essential for binding affinity to target adipocyte membrane microdomains. During solid-phase peptide synthesis (SPPS), controlled oxidation is required to form this specific disulfide bond, preventing misfolded monomeric or aggregated polymeric artifacts. For investigators seeking high-purity reference materials, examining the full spectrum of research peptides available for metabolic screening allows precise comparative evaluation of sequence modifications.
The primary mechanism identified in preclinical AOD 9604 metabolic research involves the targeted activation of lipolysis within white adipose tissue (WAT). In vitro radiolabeled glycerol and fatty acid release assays demonstrate that AOD 9604 upregulates intracellular cyclic adenosine monophosphate (cAMP) accumulation, leading to downstream activation of protein kinase A (PKA).
Activated PKA phosphorylates both perilipin-1 and hormone-sensitive lipase (HSL). Phosphorylated HSL translocates to the surface of intracellular lipid droplets, catalyzing the hydrolysis of triacylglycerol into diacylglycerol and free fatty acids. Furthermore, animal studies reveal that AOD 9604 suppresses lipogenesis by inhibiting acetyl-CoA carboxylase (ACC) enzymatic activity in isolated adipocytes, thereby dampening de novo fatty acid synthesis.
In vitro models utilizing 3T3-L1 preadipocytes and primary human subcutaneous adipocytes demonstrate that exposure to AOD 9604 results in a dose-dependent reduction in intracellular lipid accumulation during differentiation. These cellular observations coincide with marked reductions in fatty acid synthase (FAS) gene expression.
In vivo rodent research—including studies employing genetically obese (ob/ob) mice, diabetic (db/db) mice, and diet-induced obesity (DIO) Sprague-Dawley rats—demonstrates significant reductions in visceral fat mass following chronic administration of AOD 9604. Crucially, these preclinical models show that fat loss occurs without inducing insulin resistance, hyperinsulinemia, or elevations in serum IGF-1 levels. To explore related literature on growth factor pathways, review our technical overview of growth hormone fragments overview.
A major limitation of full-length somatotropin in metabolic assays is its tendency to induce insulin resistance and alter systemic carbohydrate metabolism via growth hormone receptor (GHR) dimerization. AOD 9604 bypasses these adverse pathways because it lacks the N-terminal receptor binding domain required for functional classical GHR activation.
Preclinical clamp studies reveal no impairment of peripheral glucose utilization or hepatic glucose output during treatment with AOD 9604. The peptide does not bind to the IGF-1 receptor or induce hepatic IGF-1 transcription. This isolation of lipolytic signaling from diabetogenic pathways makes AOD 9604 a preferred negative control for growth factor signaling while maintaining high specificity for lipid metabolic pathways.
When evaluating lipolytic compounds in laboratory settings, researchers often compare AOD 9604 against other peptide fragments and secretagogues. While AOD 9604 acts directly on adipocyte lipid mobilization pathways without pituitary stimulation, compounds such as Fragment 176-191 share the identical unmodified C-terminal GH sequence but lack the stabilizing N-terminal tyrosine residue. In contrast, growth hormone secretagogues like CJC-1295 No DAC and Tesamorelin stimulate endogenous pituitary somatotrophs, activating systemic IGF-1 axes along with systemic lipolytic signaling.
Understanding these mechanistic differences allows researchers to isolate direct cellular lipolysis from systemic neuroendocrine feedback loops. Additional information on receptor selectivity and pathway cross-talk can be found in our comprehensive research hub.
Reconstitution of lyophilized AOD 9604 requires strict adherence to aseptic laboratory procedures to maintain peptide stability and prevent degradation. Lyophilized vials should be allowed to equilibrate to room temperature before reconstitution to prevent moisture condensation inside the container.
For standard in vitro and analytical assays, reconstitute AOD 9604 5mg using sterile bacteriostatic water (0.9% benzyl alcohol) or sterile phosphate-buffered saline (PBS, pH 7.4). Gently swirl the vial until the cake is fully dissolved; avoid vigorous vortexing, as mechanical shear stress can cause peptide aggregation or denaturation. Reconstituted solutions should be aliquoted into polypropylene microcentrifuge tubes to prevent adsorption loss onto glass walls during repeat freeze-thaw cycles.
AOD 9604 has a molecular weight of approximately 1815.1 Da. In its lyophilized state, the peptide remains stable when stored at -20°C for up to 24 months, provided it is kept desiccated and protected from ambient light exposure.
Once reconstituted in aqueous buffer, stock solutions should be stored at 2°C to 8°C and utilized within 14 to 21 days. For long-term analytical storage, stock aliquots may be frozen at -80°C for up to 6 months. Repeated freeze-thaw cycles must be avoided to prevent peptide chain cleavage and oxidation of the internal disulfide bond.
To ensure reproducible metabolic data, researchers must source AOD 9604 verified by rigorous analytical testing. Impurities such as truncated fragments, unoxidized linear monomer, or bacterial endotoxins can confound cell culture assays and alter receptor binding kinetics.
PX1 Research provides fully USA-manufactured research peptides supported by lot-specific certificates of analysis (COA). Every production lot undergoes Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) to confirm peptide purity exceeding 99% and Electrospray Ionization Mass Spectrometry (ESI-MS) to confirm exact molecular weight. Furthermore, endotoxin levels are quantified via Chromogenic Limulus Amebocyte Lysate (LAL) testing to maintain levels strictly below 0.01 EU/mg, suitable for sensitive cell culture protocols. Institutional procurement departments can establish dedicated supply channels via our wholesale portal.
When designing in vitro metabolic experiments with AOD 9604, researchers should establish baseline dose-response curves across concentrations ranging from 10 nM to 1 µM in adipocyte cell culture models. Time-course experiments typically measure glycerol release into the culture media at 2, 4, 12, and 24 hours post-treatment.
To confirm pathway specificity, investigators frequently co-treat cells with beta-adrenergic antagonists (e.g., propranolol) or PKA inhibitors (e.g., H-89). Quantification of phosphorylated HSL (Ser563 and Ser660) via Western blot analysis serves as a reliable biomarker of target engagement. For deeper insights into lipolytic protocol design, consult our specialized guide on AOD 9604 lipolysis mechanisms.
What is the primary target of AOD 9604 in metabolic research?
In preclinical models, AOD 9604 primarily targets white adipose tissue microdomains, stimulating lipolysis via beta-3 adrenergic pathways and PKA-mediated activation of hormone-sensitive lipase (HSL), while simultaneously inhibiting de novo lipogenesis.
How does AOD 9604 differ structurally from intact human growth hormone?
AOD 9604 is a 16-amino-acid peptide corresponding to the C-terminal region (177–191) of hGH with an added N-terminal tyrosine residue. It lacks the receptor-binding domain required for classical growth hormone receptor dimerization and IGF-1 induction.
What diluent should be used to reconstitute AOD 9604 for lab research?
For routine laboratory assays, lyophilized AOD 9604 is typically reconstituted using sterile bacteriostatic water (0.9% benzyl alcohol) or sterile phosphate-buffered saline (PBS, pH 7.4), depending on assay requirements.
Does AOD 9604 affect blood glucose or insulin sensitivity in preclinical models?
Preclinical and animal studies consistently show that AOD 9604 does not alter systemic fasting glucose, impair glucose tolerance, or induce insulin resistance, separating its lipolytic effects from diabetogenic pathways.
What is the recommended storage condition for lyophilized AOD 9604?
Lyophilized AOD 9604 should be stored desiccated at -20°C or -80°C, protected from light. Under these conditions, the peptide maintains structural stability for up to 24 months.
How is the purity of PX1 Research AOD 9604 verified?
Every lot of PX1 Research AOD 9604 undergoes RP-HPLC to verify chromatographic purity (>99%), ESI-MS to confirm mass identity, and chromogenic LAL assays to ensure endotoxin levels remain under 0.01 EU/mg in ISO 17025 accredited facilities.
Can AOD 9604 be used in human clinical applications or dietary supplements?
No. AOD 9604 is strictly supplied as a research-grade compound for in vitro laboratory evaluation and preclinical animal research only. It is not for human or animal consumption, therapeutic use, or clinical administration.
Why is the disulfide bridge critical in AOD 9604 research?
The cyclic disulfide bridge between Cys7 and Cys14 stabilizes the tertiary peptide conformation, which preclinical studies have shown is essential for retaining lipolytic potency and metabolic receptor binding.
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