Noscapine HCl (CAS No.: 912-60-7) is the hydrochloride salt of noscapine, a naturally derived phthalideisoquinoline alkaloid broadly utilized in biomedical research as a modulator of microtubule dynamics and intracellular signaling pathways. This compound functions as a tubulin-binding agent that perturbs microtubule assembly, leading to mitotic arrest and the induction of apoptosis in proliferating cells, with reported antiproliferative effects observed in leukemia and multiple myeloma cell models at concentrations typically spanning the low micromolar range. In addition to its cytoskeletal effects, noscapine hydrochloride acts as a non-competitive antagonist of bradykinin receptors and modulates downstream signaling by inhibiting carbachol-stimulated phosphoinositide turnover while enhancing forskolin-induced cAMP accumulation in central nervous system tissues. It has also been shown to regulate inflammatory signaling through modulation of IKK activity and suppression of NF-κB pathway activation, supporting its use in studies of inflammation and signal transduction. Furthermore, noscapine hydrochloride interacts with sigma opioid receptors and is capable of crossing the blood–brain barrier, making it a valuable tool in neuropharmacology and CNS-related research. Owing to its multifaceted biological activities, this compound is widely applied in cell-based assays, mechanistic studies of mitosis and apoptosis, and preclinical models investigating microtubule-targeting agents, with experimental concentrations and dosing regimens varying according to specific study designs and objectives.