Horsetail for Hair Health

Research suggests that horsetail may support hair health through several biological mechanisms, including inhibition of 5α-reductase, an enzyme involved in the hormonal pathway associated with hair follicle miniaturization, as well as antioxidant and anti-inflammatory activity. Studies indicate that extracts from Equisetum species demonstrate these properties in laboratory settings, with one 2017 study finding that an ethyl acetate extract of Equisetum debile showed particularly promising results for 5α-reductase inhibition and reduced inflammatory markers without detectable toxicity in dermal papilla cells. The available evidence consists primarily of in vitro laboratory studies and a narrative review rather than human clinical trials, which means findings have not yet been confirmed in rigorous controlled settings. Overall, the research is directionally supportive but preliminary, and authors across these studies consistently call for further clinical investigation before firm conclusions can be drawn about efficacy and safety in humans.