Mangostin, a xanthone compound derived from the mangosteen fruit (Garcinia mangostana), has been investigated for various biological activities, including antiviral effects. The primary scientific interest in using mangostin to support or treat herpes stems from in vitro studies. Research indicates that α-mangostin can inhibit the replication of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) in cultured cells. For instance, a 2014 study published in Phytotherapy Research demonstrated that α-mangostin inhibited HSV-1 and HSV-2 replication by blocking viral attachment and penetration into host cells. Additional laboratory studies have supported these findings by showing dose-dependent reductions in viral activity in cell cultures treated with mangostin extracts.

However, there is no clinical trial evidence in humans supporting the efficacy of mangostin for the treatment of herpes infections. The available data are limited to laboratory (cell-based) research, and no large-scale animal or human studies have confirmed these effects in vivo. Thus, while the use of mangostin for herpes has some scientific basis at the preclinical level, it cannot currently be recommended as a proven or established therapy. The evidence rating is therefore low, reflecting the early stage of research and lack of real-world clinical validation.