Peppermint vs Spearmint: Which One Has Evidence for What?

Peppermint and spearmint are both mints, but the evidence does not point to the same uses.

Peppermint

The stronger human evidence is for enteric-coated peppermint oil in short-term IBS symptom relief. That evidence does not automatically apply to peppermint tea.

Spearmint

A small randomized trial found reductions in free and total testosterone in women with hirsutism associated with PCOS. That is early evidence, not proof that spearmint treats PCOS.

Bottom line

If the question is IBS symptoms, peppermint oil has the stronger clinical signal. If the question is androgen-related PCOS research, spearmint is the herb that has been studied. Neither should be marketed as a cure.