Spearmint (Mentha spicata) has been studied for its potential effects on estrogen levels, particularly because of its traditional use in managing conditions like hirsutism (excess hair growth) in women, which can be associated with elevated androgens (male hormones). Several small clinical studies, mainly involving women with polycystic ovary syndrome (PCOS), have investigated the effects of spearmint tea on hormonal profiles. These studies have shown that regular consumption of spearmint tea (usually twice daily for a few weeks) can lead to a significant reduction in free and total testosterone levels, with some reports of slight increases in luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The reduction in androgens is thought to occur due to anti-androgenic properties in spearmint, which may support a hormonal balance favoring estrogenic activity.

However, the direct effect of spearmint on increasing estrogen levels is less clear; most of the evidence points toward its role in lowering androgen levels rather than directly boosting estrogen. The available studies are relatively small and short-term, so while there is some scientific support for spearmint's use in modulating hormones related to the estrogen system (especially in androgen excess conditions), the overall strength of evidence remains moderate at best. More extensive, high-quality clinical trials are needed to confirm these effects and to fully understand the implications for broader estrogen support.