Spearmint leaf (Mentha spicata) has been traditionally used for various medicinal purposes, but recent scientific studies specifically highlight its potential impact on the estrogen body system, particularly in women with polycystic ovary syndrome (PCOS). Several small clinical trials and animal studies have suggested that spearmint tea consumption may help reduce androgen (male hormone) levels and increase luteinizing hormone (LH), which can indirectly influence estrogen levels and support hormonal balance.

For example, a randomized controlled trial published in Phytotherapy Research (2007) found that women with hirsutism who drank spearmint tea twice daily for five days had significantly reduced free testosterone levels, although estrogen levels did not increase significantly over the short study period. Another study in 2010 noted similar anti-androgenic effects and a trend toward increased LH and follicle-stimulating hormone (FSH), which may potentially support estrogen function over longer durations.

However, evidence is limited by small sample sizes and short durations, and there are no large-scale or long-term studies conclusively demonstrating a direct increase in estrogen levels or robust support of the estrogen system. Thus, while there is emerging scientific validation for spearmint's hormonal effects, especially in PCOS, the overall evidence is moderate and more research is necessary.