Osthol is a natural coumarin compound primarily found in the plant Cnidium monnieri and some other medicinal herbs. Its use in supporting or treating fungal infections is supported by some preliminary scientific evidence, although it has not reached the level of robust clinical validation. Several in vitro studies have demonstrated that osthol exhibits antifungal activity against a range of pathogenic fungi, including Candida albicans and Aspergillus species. The proposed mechanisms include disruption of fungal cell membranes and inhibition of fungal growth, but the exact molecular targets are still under investigation.

While these laboratory findings are promising, there are currently no well-controlled human clinical trials that confirm osthol’s efficacy or safety for treating fungal infections in humans. Most of the available research is limited to cell-based assays and sometimes animal models. As such, the overall quality and amount of evidence remain low, which is reflected in the moderate rating. Osthol’s application for fungal infections is therefore justified by early scientific inquiry rather than traditional use or comprehensive clinical studies. Healthcare professionals do not yet recommend osthol as a primary or adjunctive antifungal therapy outside of experimental settings.