Spearmint does lower testosterone, at least in women. Multiple clinical trials show that drinking spearmint tea twice daily reduces free testosterone by roughly 24–30% within five days to one month. The effect is most studied in women with polycystic ovary syndrome (PCOS) and excess hair growth, and no human trials have tested spearmint’s hormonal effects in men.
What the Clinical Trials Show
The earliest trial, conducted in Turkey, had 21 women with excess body hair drink one cup of spearmint tea twice daily for just five days. Free testosterone dropped by about 30%. Total testosterone and another androgen precursor (DHEAS) stayed the same, suggesting that spearmint doesn’t shut down androgen production entirely but changes how testosterone circulates in the body.
A longer, more rigorous trial followed. Forty-two women with PCOS were randomized to drink spearmint tea or chamomile tea (as a placebo) twice daily for 30 days. By the end of the month, the spearmint group had significant reductions in both free testosterone (24%) and total testosterone (29%). The chamomile group saw no change. Women in the spearmint group also reported subjectively thinner body hair, though objective scoring of hair density didn’t show a measurable difference in that short window.
A more recent double-blind trial took a slightly different approach, giving women capsules containing 50 mg of dried spearmint leaves combined with 50 mg of dried green tea leaves daily for three months. After that period, hirsutism scores dropped by 25–50% compared to placebo. Testosterone levels declined by about 15% in women with PCOS and 12% in women without it. The lower percentage compared to the tea-only trials may reflect the different preparation, the addition of green tea, or longer observation smoothing out early hormonal shifts.
How Spearmint Affects Hormones
Spearmint appears to work through at least two pathways. First, it speeds up the rate at which the body breaks down androgens by activating a specific liver enzyme involved in hormone metabolism. This clears free testosterone from the bloodstream faster than usual. Second, as free testosterone drops, estrogen levels rise slightly. Higher estrogen prompts the liver to produce more of a protein called sex hormone-binding globulin (SHBG), which binds to testosterone and makes it inactive. That’s why some studies find total testosterone levels unchanged: the testosterone is still there, but a larger share is bound up and unable to act on tissues like hair follicles and skin.
The trials also consistently show increases in luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol after spearmint consumption. In women with PCOS, where these hormones are often out of balance, those shifts are meaningful because they suggest a broader recalibration of reproductive hormones rather than a simple suppression of one.
What About Men?
There are no published human trials measuring spearmint’s effect on testosterone in men. The concern comes primarily from animal research. Rat studies have shown that high doses of spearmint extract can damage testicular tissue, reduce testosterone levels, and alter LH and FSH. One widely cited observation suggests that daily consumption of four cups of spearmint tea could diminish libido in men, though this comes from animal-extrapolated data rather than a controlled human study.
For men who enjoy the occasional cup of spearmint tea, the existing evidence doesn’t indicate a hormonal risk at normal intake. The doses that caused problems in animal studies were substantially higher, relative to body weight, than what a person would get from one or two cups a day. That said, men specifically trying to avoid any anti-androgenic effect may want to keep intake moderate until human data exists.
Dosage Used in Studies
Every major trial used the same basic protocol: one cup of spearmint tea, steeped from dried leaves, consumed twice per day. The shortest study lasted five days and still produced measurable hormonal changes. The 30-day trial showed larger, more consistent reductions. The three-month capsule study used a lower dose (50 mg dried leaves per day, combined with green tea) and still achieved results, though the testosterone reduction was more modest.
No study has directly compared tea to capsules head-to-head, so it’s unclear whether one form is meaningfully better than the other. The tea-based studies used higher quantities of spearmint overall and generally showed steeper testosterone drops, but the studies differed in too many other ways to draw a firm conclusion about form alone.
How Long Before You See Results
Hormonal changes begin quickly. Blood levels of free testosterone shift within five days of twice-daily tea consumption. However, the physical effects people care about most, particularly reduced unwanted hair growth, take much longer. Hair has its own growth cycle, and even with lower testosterone driving new growth, existing hairs need time to shed naturally. Researchers behind the 30-day trial noted that a much longer study would be needed to see visible changes in hirsutism, and the three-month capsule trial was the first to show meaningful reductions in hair scoring.
If you’re using spearmint for hormonal hair concerns, expect to commit to at least two to three months of consistent daily intake before gauging whether it’s working for you.
Safety Considerations
At the doses used in clinical trials (two cups of tea per day for up to 30 days), no adverse effects were reported in women. The safety picture gets murkier at higher doses and longer durations. Animal studies using concentrated spearmint extract have found tissue changes in the kidneys, liver, and uterus, and rare cases of contact allergic reactions to spearmint leaves have been documented.
The biggest practical concern is for men or for anyone consuming very high amounts. The anti-androgenic properties that make spearmint appealing for women with PCOS are the same properties that could, in theory, cause unwanted hormonal suppression in people who don’t want lower testosterone. High-dose, long-term use without monitoring is where the risk appears to concentrate based on available animal data.