Maca Root for Erectile Dysfunction

Only one trial has tested maca root specifically in men with erectile dysfunction. In it, 50 men with mild ED took 2,400 mg of maca dry extract or placebo for 12 weeks. Erection scores on the IIEF-5 questionnaire rose in both groups, more on maca (1.6 points versus 0.5, P < 0.001), and the authors described the effect as small [1]. A 2018 meta-analysis of herbal ED treatments called the result very preliminary [2], and a 2026 meta-analysis of 14 trials concluded the evidence for maca remains insufficient [3].

A second trial, in 80 men with symptoms of late-onset hypogonadism but normal testosterone, found erectile-function scores improved more on maca than on placebo over 12 weeks [4]. That is the whole controlled evidence base for erections. Proven treatments exist: in a network meta-analysis of 179 randomised trials (50,620 men), every PDE5 inhibitor beat placebo, and the authors named low-dose sildenafil and tadalafil as the first options [5]. In addition, the American Urological Association asks clinicians to discuss every suitable option with each man [6].

Maca (Lepidium meyenii) is a root of the brassica family, grown in the Peruvian Andes and used there for centuries as food and traditional medicine. Over the last twenty years it has been marketed worldwide as 'Peruvian ginseng' for libido and fertility. Its distinctive compounds, macamides and glucosinolates, are credited with its effects, but a 2018 review found this cannot be confirmed for lack of data [7].

Maca does not seem to work by raising testosterone. In a 12-week trial in healthy men aged 21-56, maca at 1,500 or 3,000 mg a day improved self-rated sexual desire from week 8, while serum testosterone and oestradiol did not differ from placebo [8]. Desire and erections are different problems, though, and better libido does not show better erections; see maca for low libido.

The most direct mechanistic evidence comes from animals. In mice, a combined extract of maca root and Chinese chive seed increased ejaculation frequency and raised nitric oxide and cGMP in penile tissue, changes the authors suggested may explain the effect [9]. That was a two-plant mixture given to mice at 200 mg/kg, and it does not show the same happens in men.

In people, Memorial Sloan Kettering's review notes that maca does not change LH, FSH, prolactin, testosterone or oestradiol in men [10]. No human study has shown how maca might affect erectile function, so the small trial results stand without a confirmed mechanism behind them.

The ED trial gave 2,400 mg of maca dry extract a day for 12 weeks [1]. In the trial in men with ageing-related symptoms, the abstract describes 1,000 mg of gelatinised maca taken as two pills three times a day before food, also for 12 weeks, without making the daily total clear [4]. Trials of sexual desire and of antidepressant-related sexual problems used 1.5-3.0 g a day; in a small dose-finding study, only 3.0 g, not 1.5 g, improved sexual-function scores [8][11].

Products are not interchangeable. A review warned that mass production, including cultivation outside the Andes, can change the plant's chemistry and so the quality and effects of maca products [7]. Colour types also differ: in one trial, black maca extract contained more macamides and red maca more GABA [12].

In 50 Caucasian men with mild ED, randomised double-blind to 2,400 mg of maca dry extract or placebo for 12 weeks, IIEF-5 scores rose significantly in both groups (P < 0.05 for both) but more on maca: 1.6 ± 1.1 versus 0.5 ± 0.6 points (P < 0.001). Maca also improved psychological well-being scores more than placebo (+9 versus +6, P < 0.05), and only the maca group improved on physical and social well-being scores [1].

The authors concluded there was a small but significant effect on how men perceived their general and sexual well-being [1]. All outcomes were self-reported questionnaires, the placebo group improved too, and the trial has not been repeated in men with ED.

A double-blind trial in 80 men with symptoms of late-onset hypogonadism but normal testosterone (eugonadal) compared gelatinised maca (41 men) with placebo (39 men) for 12 weeks. Ageing-male symptom (AMS), erectile function (IIEF) and prostate symptom (IPSS) scores all improved significantly more on maca (P < 0.05) [4].

The abstract does not report how large the IIEF change was, and the men were not selected because they had ED, so this is supportive rather than direct evidence for erectile dysfunction.

A 2010 systematic review found four placebo-controlled trials of maca for sexual function, the ED trial among them, and judged the evidence limited: too few trials, too few participants and too low in quality for firm conclusions [14]. In 2018, a meta-analysis of 24 herbal ED trials (2,080 men) found encouraging evidence only for ginseng and called the single maca trial of 50 men very preliminary [2]. A 2026 meta-analysis of 14 trials (1,227 men) found saffron and ginseng effective but evidence for maca and Tribulus insufficient [3].

A 2024 network meta-analysis of 15 nutraceutical trials (1,000 men) concluded that most nutraceuticals were ineffective, with only L-arginine and a carnitine mixture showing some usefulness, mainly alongside PDE5 inhibitors [15]. A broad review of plants used for ED lists maca among the most used but describes clinical results for such plants as mixed [16]. If you want a better-studied option, see Korean ginseng for ED and L-arginine for ED.

In a pilot dose-finding trial in 20 people with sexual dysfunction caused by SSRI antidepressants (17 of them women), 3.0 g a day improved sexual-function scores and 1.5 g did not; there was no placebo group [11]. A later 12-week placebo-controlled trial in 45 women found somewhat higher remission rates on 3.0 g a day, mainly in postmenopausal women [17]. Neither tested erections in men with ED.

Maca appears well tolerated in the short term. In a 12-week placebo-controlled trial, 175 adults took 3 g a day of red or black maca extract with good acceptability and no serious adverse effects [12], and both antidepressant trials reported it was well tolerated [11][17]. In the 19 of 24 herbal ED trials that recorded adverse events, mostly of products other than maca, rates did not differ significantly from placebo [2].

Memorial Sloan Kettering lists subjective reports of altered menstrual cycles, moodiness, cramps, gastritis and insomnia, and notes maca may interfere with testosterone blood tests; one case report described a woman with prolonged bleeding and raised testosterone readings after taking maca powder [10]. MSKCC also advises women who are pregnant or breastfeeding to talk to a clinician first, as maca may not be safe for them [10]. None of the trials on this page lasted beyond 12 weeks, so long-term safety is unknown.

Product quality is a separate risk. In 2019 the FDA found sildenafil, the active ingredient in Viagra, undeclared in a product sold as maca, and warned that hidden sildenafil may interact with nitrate medicines such as nitroglycerin and lower blood pressure to dangerous levels. The FDA notes that products with hidden drug ingredients are typically promoted for sexual enhancement [18].

Few interactions are documented. Memorial Sloan Kettering advises people with hormone-sensitive cancers, such as breast or uterine cancer, to talk to their clinician because maca may affect treatment, and warns that it can distort testosterone test results [10]. Maca was taken alongside SSRI antidepressants in two trials without reported problems [11][17]. Neither trial that measured erections combined maca with a PDE5 inhibitor, so nothing is known about that combination [1][4]. The most serious risk comes from adulterated products: hidden sildenafil found in a product sold as maca can interact dangerously with nitrates [18].