Maca is a root vegetable from the Peruvian Andes, sold as a supplement primarily for its effects on libido, energy, and hormonal balance. Most clinical research centers on sexual desire, fertility support, and relief from menopause symptoms. Notably, maca appears to produce many of these effects without directly raising or lowering sex hormone levels in the blood, which makes its mechanism unusual among supplements marketed for hormonal health.
How Maca Affects the Body
One of the most surprising things about maca is what it doesn’t do: it doesn’t significantly change circulating levels of testosterone or estrogen in most studies. A controlled trial in healthy men found that maca improved sexual desire over 8 to 12 weeks, but serum testosterone and estrogen levels were no different between the maca group and the placebo group. Statistical analysis confirmed the libido improvement was independent of any hormone shift or changes in mood.
Researchers have proposed that maca’s active compounds interact with the signaling chain between the brain and the hormone-producing glands (the hypothalamus, pituitary, and adrenal or ovarian glands). In postmenopausal women, one study found that maca stimulated estradiol production while simultaneously lowering levels of stress hormones like cortisol and ACTH, along with certain thyroid and reproductive signaling hormones. But in men, those same hormonal shifts don’t appear. The working theory is that maca acts more like a modulator, nudging the body’s hormonal communication rather than flooding it with a specific hormone. This hypothesis hasn’t been fully confirmed.
Effects on Libido and Sexual Function
Libido improvement is the most consistently reported benefit of maca supplementation. In a randomized, double-blind pilot study of people experiencing sexual dysfunction from antidepressant medications, maca produced a statistically significant improvement in libido scores. Participants started with an average libido rating of about 4.9 out of 6 on a standardized scale (where higher means worse function) and improved to 3.6 after supplementation. That’s a meaningful shift on a scale where each point represents a noticeable change in day-to-day desire.
The effect showed up regardless of dose (both low and high doses improved scores), and both men and women in the study experienced similar degrees of improvement, though the sample sizes were small. In the separate trial of healthy men mentioned above, increased sexual desire became apparent by the 8-week mark and persisted through 12 weeks. Importantly, this wasn’t explained by mood changes: the men’s depression and anxiety scores stayed the same while their reported desire went up.
Menopause Symptom Relief
For women in early postmenopause, maca has shown broad benefits across the cluster of symptoms that make this transition difficult. In a double-blind, placebo-controlled crossover study, maca treatment produced highly significant reductions in both the frequency and severity of hot flashes and night sweats. Beyond those hallmark symptoms, the same study reported significant improvement in nervousness, mood swings, interrupted sleep, fatigue, stress, headaches, depression, and decreased libido.
The study also found that maca increased markers associated with bone density, which is relevant because bone loss accelerates after menopause. Estradiol levels rose during maca treatment while stress-related hormones dropped, suggesting the root helps shift the hormonal environment in a direction that eases the menopausal transition. Body mass index also decreased during the treatment period.
Sperm Quality in Men
A clinical trial in adult men found that maca supplementation improved several measures of sperm quality: total volume, sperm count per ejaculation, the number of motile (actively swimming) sperm, and overall sperm motility. These improvements occurred without any change in testosterone, estrogen, or the pituitary hormones that typically regulate sperm production, which again points to maca working through a different pathway than direct hormone manipulation. The improvements were also not dose-dependent, meaning a lower dose produced similar results to a higher one.
Mood and Blood Pressure
A pilot study in postmenopausal women found that maca supplementation led to significant decreases in both diastolic blood pressure and depression scores, measured using validated quality-of-life scales. A separate Australian study similarly reported improvements in anxiety and depressive symptoms. These mood benefits may partly explain why maca has a reputation as an “energy” or “vitality” supplement, since reduced anxiety and improved mood often translate into feeling more energetic day to day. That said, these studies were small, and the mood effects weren’t large enough to position maca as a standalone treatment for clinical depression or anxiety.
Yellow, Red, and Black Varieties
Maca root comes in three color types, and they aren’t interchangeable. Yellow maca is the most common and least expensive variety. It has a milder effect profile and is often recommended as a starting point. Red maca is rarer, more stimulating, and contains higher concentrations of beneficial plant compounds. Black maca is the rarest and most expensive. Research on male fertility has primarily used black maca, while red maca has been more studied for prostate health and bone density, though all three colors share a core set of active compounds.
Raw vs. Gelatinized Forms
You’ll find maca sold as either raw powder or gelatinized powder (and in capsules made from either). The difference matters mainly for your stomach. Raw maca retains all its natural starch, which can cause gas, bloating, or loose stools in some people, especially at higher doses. Gelatinized maca has been pre-cooked under heat and pressure to break down most of that starch while preserving the active compounds (macamides, macaenes, and other plant chemicals responsible for its effects). If you’ve tried maca before and had digestive issues, the gelatinized form is the more practical choice.
Dosage and How Long It Takes to Work
Most clinical trials have used doses ranging from 1.5 to 3 grams per day, typically taken as a powder or in capsule form. The libido studies showed measurable changes starting around 6 to 8 weeks, with effects continuing to build through 12 weeks. This is not a supplement that works overnight. If you’re trying maca for sexual desire, mood, or menopause symptoms, plan on at least two months of consistent daily use before evaluating whether it’s helping. Starting at the lower end of the dose range and increasing gradually can help you gauge tolerance, particularly if you’re using raw powder.