Tat-QFNP12 is a peptide that combines a transcriptional transactivator (Tat) transmembrane domain with an inhibitor targeting the interaction between N-Myc downstream regulated gene 2 (NDRG2) and protein phosphatase Mg2+/Mn2+ dependent 1A (PPM1A). This compound effectively mitigates blood-brain barrier endothelial tight junction disruption caused by elevated levels of matrix metalloproteinase-9 (MMP-9), alleviates cerebral edema, and promotes spontaneous activity along with symmetric limb movement in a mouse model of subarachnoid hemorrhage induced by endovascular puncture. These benefits are observed at a dosage of 20 mg/kg.