Dr. Rachel StoneMaca (Lepidium meyenii) is a cruciferous root vegetable native to the high Andes of Peru, traditionally used for energy, fertility, and hormonal balance. It’s one of the few adaptogenic plants grown in its native soil at 4,000+ metres altitude, where it’s been cultivated for over 3,000 years. Here’s what modern research shows about its benefits — and its limits.
What Is Maca?
Maca is not a mushroom or herb — it’s a root vegetable related to broccoli and cabbage. Its active compounds include glucosinolates (the same anti-cancer compounds in cruciferous vegetables), macamides and macaenes (fatty acids unique to maca), alkaloids, minerals, and sterols. Critically, maca does not contain hormones and does not directly raise or lower oestrogen, testosterone, or other sex hormones. Its hormonal effects appear to be indirect, through the hypothalamic-pituitary-gonadal (HPG) axis.
1. Sexual Function and Libido
This is maca’s most studied and best-evidenced benefit. Multiple RCTs have found maca supplementation improves sexual desire and function in both men and women without directly altering sex hormone levels — suggesting a central (brain/hypothalamic) rather than hormonal mechanism.
A 2002 RCT in healthy men (1,500–3,000mg maca daily for 12 weeks) found significant increases in sexual desire at 8 weeks with no changes in testosterone or oestrogen. A 2008 small RCT found maca supplementation significantly improved sexual dysfunction in SSRI-induced sexual dysfunction patients — a particularly difficult-to-treat population. A 2015 systematic review of 4 RCTs concluded there is “limited evidence that maca improves sexual dysfunction or sexual desire.”
2. Menopause Symptoms
Multiple studies have found maca reduces menopause symptoms — particularly hot flushes, night sweats, and mood disturbances. A 2006 pilot study in postmenopausal women found maca reduced total menopause symptom scores and reduced blood pressure compared to baseline. A 2008 RCT found maca significantly reduced psychological symptoms of menopause (anxiety, depression, sexual dysfunction) without altering oestrogen or FSH levels.
The mechanism remains somewhat unclear — maca appears to support the hypothalamic-pituitary axis regulation of hormones rather than acting as a phytoestrogen, which makes it potentially safer for women with oestrogen-sensitive conditions than phytoestrogen-containing herbs.
3. Male Fertility and Sperm Quality
Several studies have found maca improves sperm parameters in men. A 2001 study found maca supplementation (1,500 or 3,000mg daily for 4 months) significantly increased sperm count, sperm motility, and seminal volume compared to placebo. A 2009 study in men with mild erectile dysfunction found maca significantly improved erectile function and overall sexual well-being scores. These effects occurred without changes in testosterone or FSH, again suggesting a hypothalamic mechanism.
4. Energy and Physical Performance
Maca’s traditional use as an energy food for Andean warriors is supported by some modern research. A 2009 study in cyclists found maca supplementation (2g daily for 14 days) improved 40km cycling time trial performance and sexual desire compared to placebo. The energy effect may relate to maca’s glucosinolate and macamide content, which support mitochondrial function.
5. Mood and Cognitive Function
Maca has documented mood-improving effects in postmenopausal women, reducing anxiety, depression, and cognitive fog. A 2015 study found black maca supplementation specifically improved learning and memory in animal models — an effect attributed to its glucosinolate content and effects on the acetylcholine system. Human cognitive data is limited but consistent with animal findings.
6. Bone Health
Maca is rich in calcium, iron, zinc, and manganese — minerals critical for bone density. Animal studies show maca supplementation prevents bone loss in ovariectomised (oestrogen-deficient) rats, with effects attributed to its mineral content and potential effects on osteoblast activity. Human bone data is limited.
Maca Colours — Does It Matter?
| Colour | Best Evidence For |
|---|---|
| Yellow/cream maca | General energy, libido (most common; most research) |
| Red maca | Bone health, prostate health (animal studies) |
| Black maca | Sperm quality, cognitive function, physical performance |
How to Take Maca
Clinical trials typically use 1,500–3,000mg daily of gelatinised maca powder (gelatinisation improves digestibility and bioavailability by removing raw starch). Raw maca can cause digestive discomfort in some people — gelatinised is preferable. It can be stirred into smoothies, oatmeal, or coffee. Maca has a malty, slightly earthy flavour that is generally well-tolerated.
Frequently Asked Questions
Maca root’s best-evidenced benefits are: improved sexual desire and function in both men and women (without directly altering sex hormones), reduced menopause symptoms (hot flushes, mood, anxiety), improved sperm quality and male fertility, modest energy and physical performance improvement, and mood support. It appears to work through the hypothalamic-pituitary axis rather than through hormone production, making it a potentially safer hormonal support option.
No — maca does not directly raise testosterone. Multiple RCTs confirming maca’s libido and sexual function benefits found no changes in serum testosterone, oestrogen, LH, or FSH. The sexual and hormonal effects appear to be mediated through central nervous system mechanisms (hypothalamic modulation) rather than direct hormone production. This is both a benefit (safer profile) and a distinction from supplements that directly raise testosterone.
The 2002 libido RCT found effects on sexual desire at 8 weeks with no effect at 4 weeks — suggesting maca requires consistent use for 6–12 weeks before meaningful effects develop. Menopause symptom trials typically show improvements at 6–8 weeks. Energy effects may be more rapid — the cycling performance study used only 14 days of supplementation. Consistent daily use is more important than dose escalation.
Maca does not contain phytoestrogens and does not directly raise oestrogen — making it potentially safer than soy or red clover for women with oestrogen-sensitive conditions. However, its indirect effects on the hypothalamic-pituitary axis mean it could theoretically influence hormone balance. Women with ER-positive breast cancer, endometriosis, or fibroids should consult a healthcare provider before use due to limited safety data in these populations.
This article is for informational purposes only and does not constitute medical advice. Consult a healthcare provider before use, particularly if you have hormone-sensitive conditions.
Sarah Mitchell
Elena Voss
James Hargreaves
