Dynorphin A is a 17-amino-acid endogenous opioid peptide that acts preferentially at kappa opioid receptors, participating in pain modulation, stress response and neuroendocrine regulation in research models. It is supplied as a high-purity white lyophilized powder at >=99% HPLC purity in sealed vials, offering good stability and easy reconstitution. It is widely used in opioid-receptor pharmacology, analgesia research, dependence studies and neurochemistry experiments examining kappa-opioid signaling. Quality control is performed on each batch with batch COA available on request. Keep the product sealed at 2-8 degree C, protected from light and moisture; for long-term storage -20 degree C is recommended and repeated thawing should be avoided. We accept both sample and bulk orders, offer OEM and private label service, and arrange discreet neutral packing for worldwide shipping. Intended for laboratory research only, not for human or veterinary application.