Opioid Receptor Antagonist Ac-RFMWMK-NH2 Peptide; μ/δ/κ-OR inhibitor. Price Not Available 1 mg Opioid Receptor Antagonist Ac-RFMWMK-NH2 Supplier Page Catalog Number O6132 Molecular Formula C44H66N12O7S2 Purity ≥98% Size 1 mg