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Limited evidenceBrain & cognition

Spearmint Extract

Standardized spearmint extract (the rosmarinic-acid-rich Neumentix ingredient) has produced small, statistically significant attention improvements in a handful of trials — all funded by the ingredient's manufacturer. Promising but not independently confirmed, and unrelated to the separate spearmint-tea-for-PCOS literature.

What the science says

  • Improves sustained attention and working memory Limited evidence

    In a 90-day placebo-controlled trial of 142 healthy adults, 900 mg/day of spearmint extract standardized to about 14.5% rosmarinic acid improved sustained attention performance versus placebo, with effects appearing on some but not all tasks in the battery. A separate trial in older adults with subjective memory complaints reported roughly 10-15% better working memory scores at the same dose. Every published trial to date shares one commercial sponsor and one proprietary extract, which is the main reason this rating is not higher.

  • Reduces reactive agility decline and improves executive function after physical stress Limited evidence

    In a controlled trial in soldiers, spearmint extract containing rosmarinic acid attenuated declines in reactive agility and executive function measured after a demanding tactical operation. Sample size was small and the outcome battery was exploratory.

  • Lowers free testosterone in women with PCOS or hirsutism Limited evidence

    This claim comes from spearmint tea (two cups daily for 30 days), not the standardized cognitive extract, and while small trials show significant reductions in free testosterone, hirsutism scores did not measurably improve over 30 days — too short for hair-growth cycles. Do not assume a 900 mg attention-focused capsule reproduces a tea-based hormonal effect.

  • Relieves knee osteoarthritis pain Limited evidence

    A high-rosmarinic-acid spearmint tea has been tested in knee osteoarthritis with modest reported improvements in stiffness and physical disability over 16 weeks in small samples. Independent replication is absent.

Dosage & safety

Studied doseCognitive trials used 900 mg/day of dried spearmint extract standardized to at least 14.5% rosmarinic acid (roughly 130 mg rosmarinic acid), taken for 30-90 days; acute effects have been reported within 2 hours of a single 900 mg dose. Hormonal spearmint studies used two cups of spearmint tea daily. Ordinary spearmint leaf capsules are not equivalent to the standardized extract.
SafetyWell tolerated in trials, with adverse event rates similar to placebo; occasional GI upset. Spearmint relaxes the lower esophageal sphincter like peppermint and can aggravate reflux. The antiandrogenic signal from spearmint tea means men concerned about testosterone should be aware of it, and it should be avoided in pregnancy at medicinal doses. No doping restrictions. Note that spearmint is not peppermint — do not substitute peppermint oil products for these results.

Scientific references

Where to buy

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