Butylphthalide, particularly its synthetic form DL-3-n-butylphthalide (NBP), has been used in China as a treatment for ischemic stroke. Its use is supported by several preclinical and clinical studies, although most research has been conducted in China and large-scale international endorsement is lacking. Mechanistically, butylphthalide is believed to offer neuroprotection through multiple pathways, including improvement of microcirculation, reduction of neuronal apoptosis, anti-inflammatory effects, and inhibition of platelet aggregation. Preclinical animal studies have shown that NBP can decrease infarct size and improve neurological function after stroke.

Several randomized controlled trials and meta-analyses performed in Chinese populations have reported that NBP, when used alongside standard therapy, can improve neurological outcomes in patients with acute ischemic stroke. For example, a 2017 meta-analysis (Wu et al., Scientific Reports) concluded that NBP was associated with better functional recovery and reduced neurological deficits compared to placebo. However, these studies often have methodological limitations such as small sample sizes, short follow-up periods, and lack of blinding. As of 2024, butylphthalide is approved for stroke treatment in China but not in most Western countries, where regulatory agencies call for more rigorous evidence.

In summary, the use of butylphthalide for stroke is supported by scientific evidence, primarily from Chinese research, but the quality and generalizability of this evidence is moderate. The evidence rating is 3 out of 5.