Spearmint tea may be used as a treatment for hirsutism in women. Its antiandrogenic properties reduce the level of free testosterone in the blood, while leaving total testosterone and DHEA unaffected.^[10] However, administration of spearmint tea to rats causes dose-dependent, temporary or permanent negative effects on the reproductive system of the male rat and leads to lipid peroxidation that results in histopathologies in the kidney, liver, and uterine tissues;^[11] more research into the toxic effects of the tea in humans is warranted. It can also be used to treat a variety of digestive ailments.^[12]

Spearmint has been studied for antifungal activity; its essential oil was found to have some antifungal activity, although less thanoregano.^[13] Its essential oil did not show any evidence of mutagenicity in the Ames test.^[13] It can have a calming effect when used for insomnia or massages.^[12] Spearmint has also been described as having excellent antioxidant activity, comparable to the syntheticBHT.^[14] Due both to its antioxidant activity and its common use to season lamb in Indian cuisine, it has been studied as an additive to radiation-processed lamb meat, and was found effective in delaying oxidation of fats and reducing formation of harmful substances, which can be detected using thiobarbituric acid as a reagent.^[14]