How Long Does It Take for Maca to Increase Libido?

Most clinical trials that have found a libido benefit from maca root report improvements emerging around eight to twelve weeks of daily use, with some evidence that changes begin as early as eight weeks. That timeline comes from a handful of small but well-designed studies, and the honest caveat is that “a handful” is doing heavy lifting here. The research base is thin enough that no one can give you a precise week-by-week forecast, but the pattern across trials is consistent enough to set reasonable expectations.

What the Clinical Trials Actually Report

The most commonly cited timeline comes from a trial in healthy adult men that tracked sexual desire over twelve weeks. Researchers found that self-reported desire improved at both the eight-week and twelve-week marks compared to placebo, and that this effect was independent of changes in mood, anxiety, or hormone levels.¹ That last point matters and we will come back to it, but on the timeline question alone: the men did not report meaningful changes in the first few weeks. The effect showed up reliably only from week eight onward.

A separate trial in women experiencing sexual side effects from antidepressants ran for twelve weeks. In the overall group, differences between maca and placebo were modest, but among postmenopausal women, maca produced notably higher rates of improvement in orgasm. Premenopausal women on maca, meanwhile, saw gains in arousal rather than orgasm.² Again, the trial ran twelve weeks, and no interim analysis suggested that benefits materialized in the first month.

A dose-finding pilot study, also twelve weeks long, found that participants taking 3.0 grams per day showed significant improvements on validated sexual function questionnaires, while those taking 1.5 grams per day did not.³ Libido specifically (measured as a single questionnaire item about desire) did improve across all participants regardless of dose group, but the broader improvements in sexual function were dose-dependent. The takeaway on timing: none of these trials were designed to pinpoint the exact week effects begin, because they mostly measured outcomes at the end of the trial period. What we can say with confidence is that twelve weeks at an adequate dose is the tested window.

Why You Should Not Expect Results in Days or Even Two Weeks

If you have seen supplement marketing claiming you will feel a difference in a week, that is not backed by published evidence. A systematic review of maca and sexual function found that trial durations ranged from two to twelve weeks, with dosages between 1.5 and 3.5 grams daily.⁴ The two-week studies in that review were not focused on libido per se; the trials that specifically measured sexual desire and found positive results were the longer ones. No published trial has demonstrated a meaningful libido increase in under four weeks.

This is not unusual for a plant-based supplement. Maca is not a stimulant, and it does not act like a pharmaceutical designed for rapid onset. Whatever mechanism is responsible for its effects on desire appears to build gradually. People who try maca for a week, feel nothing, and conclude it does not work may simply be quitting before the window in which effects have been observed.

Dose Appears to Matter

The dose-finding study mentioned earlier is one of the few trials to directly compare different amounts. At 3.0 grams per day, participants saw statistically meaningful improvements in overall sexual function scores. At 1.5 grams per day, they did not.³ The systematic review confirmed that most positive trials used somewhere in the range of 1.5 to 3.5 grams daily, but noted that the optimal dose remains unknown.⁴

In practical terms, if you are taking a capsule that contains 500 milligrams and you are only taking one per day, you are well below the doses used in trials. Most supplement labels recommend two to three capsules daily, which puts you in the 1.5 to 3.0 gram range assuming the capsules contain straight maca powder rather than a concentrated extract. If the label says “extract” and lists a smaller amount, the concentration ratio should be stated, but not all brands are transparent about this. A product advertising “10:1 extract” at 500 milligrams is nominally equivalent to 5 grams of raw maca powder, but extraction methods vary, and “equivalent” claims on supplement labels are not rigorously standardized.

The bottom line on dose and timing together: the evidence that exists points to roughly 3 grams per day of maca root powder for at least eight weeks as the combination that has shown results. Going lower on dose or shorter on duration puts you in territory where the published trials did not find much.

It Does Not Work Through Testosterone

One of the more interesting findings about maca is that its effect on desire does not appear to be hormonal, at least not in the way most people assume. The trial in healthy men measured serum testosterone and estradiol throughout the study period and found no difference between the maca group and the placebo group at any time point. Statistical analysis confirmed that maca’s effect on sexual desire was independent of testosterone levels, depression scores, and anxiety scores.¹

This is counterintuitive. Libido in both men and women is influenced by testosterone, so a supplement that improves desire without touching testosterone is doing something unexpected. The actual mechanism remains unclear. Researchers have speculated that bioactive compounds in maca, including a class of compounds called macamides and macaenes, may act on the central nervous system in ways that influence sexual motivation without altering circulating hormone levels. But this is speculation grounded in animal studies and phytochemical analysis, not confirmed by human trials showing a specific pathway.

For you as a consumer, this has a practical implication: if a brand markets maca as a “natural testosterone booster” and claims that is how it improves your sex drive, the evidence contradicts that framing. The libido benefit, to whatever extent it exists, seems to operate through some other route entirely.

Different Results for Men and Women

The trials suggest that maca may affect men and women somewhat differently, and menopausal status matters for women. In the trial of women with antidepressant-related sexual difficulties, the standout subgroup was postmenopausal women. They had notably higher rates of improvement in orgasm compared to the placebo group, while premenopausal women saw improvement in arousal instead.² The subgroup sizes were very small (seven postmenopausal women on maca), so these numbers should be treated cautiously, but the pattern is at least suggestive.

In healthy men, the effect was more straightforward: desire increased on a self-report measure, and the effect was consistent enough to show up in statistical modeling even after controlling for mood.¹ But these were men without sexual complaints at baseline. Whether maca helps men who are specifically experiencing low libido as a primary concern is less clear from the available evidence.

The systematic review that pooled findings across multiple trials noted that positive results turned up in healthy menopausal women, healthy adult men, and men with erectile dysfunction, but a trial in healthy male cyclists found no effect.⁴ The cyclist result is a reminder that not every population responds, and fitness level, baseline sexual function, or other factors may influence whether maca makes a noticeable difference.

How Reliable Is the Evidence?

This is where honest assessment requires some uncomfortable candor. The total number of randomized controlled trials on maca and sexual function is small. The systematic review identified only four that met inclusion criteria, and even those had limitations including small sample sizes and varying outcome measures.⁴ Two of those four found a significant positive effect, one found improvement in erectile dysfunction scores, and one found nothing.

That is not a disaster for a herbal supplement. Many popular supplements have less rigorous evidence behind them. But it means you should calibrate your expectations accordingly. Maca is not a drug with Phase III trial data from thousands of participants. It is a traditional Peruvian root vegetable with a few small, methodologically decent trials suggesting it helps some people with desire and arousal over a two- to three-month window. The effect sizes, where reported, are real but modest. In the dose-finding study, average sexual function scores improved from about 23 to about 17 on a scale where lower is better, which translates to a meaningful but not dramatic shift.³

Placebo effects are also worth considering. Sexual desire is heavily influenced by expectation, mood, and context. If you start taking a supplement you believe will help, the act of taking it daily and anticipating improvement can itself shift your experience of desire. The placebo groups in maca trials did show some improvement, as is typical in sexual function research. The maca groups improved more, which is why the statistical tests came back positive, but the gap between maca and placebo was not enormous.

Safety and Side Effects

One genuinely encouraging aspect of the maca research is the safety profile. A comprehensive pharmacological review concluded that maca is generally safe, with rare adverse effects, and that both preclinical animal data and human tolerance data support this.⁵ The dose-finding trial noted that maca was well tolerated at both 1.5 and 3.0 grams per day.³

Reported side effects in trials are generally mild and infrequent. Some people notice digestive changes, which makes sense given that maca is a root vegetable rich in fiber and carbohydrates. If you are trying maca for the first time, starting at a lower dose and increasing over a week or two is a reasonable approach just to let your gut adjust, even though the lower dose alone may not produce a libido effect.

There are some populations that should be cautious. Maca belongs to the cruciferous vegetable family, the same group as broccoli and cabbage, and contains compounds called glucosinolates. People with thyroid conditions have occasionally been advised to be careful with high intakes of cruciferous vegetables, though the evidence that normal dietary amounts cause thyroid problems is weak. If you are on thyroid medication, it is worth mentioning maca to your doctor, especially at supplement-level doses.

Maca Color and Preparation Differences

Maca roots come in several colors, including yellow, red, and black, and supplement brands sometimes market specific colors for specific purposes. You will see claims that black maca is “best for men” or that red maca is “best for women” or for mood. Some preliminary research, mostly from animal studies, does suggest that different color varieties have somewhat different phytochemical profiles and may have different biological activities. But the human libido trials discussed above used maca root without specifying color variety in most cases, or used a mixture. There is currently no human trial that directly compares one maca color against another for sexual function outcomes.

The same gap applies to preparation method. Maca is traditionally consumed as a cooked root or dried powder. Modern supplements come as raw powder, gelatinized powder (which has had starch removed through heating), or various extracts. Gelatinized maca is often marketed as more digestible and more concentrated, but whether it is more effective for libido has not been tested head-to-head against raw powder in a trial. The systematic review noted that it remains unclear to what extent the therapeutic effects depend on the type of maca used or the specific amounts of its various constituents.⁴

If you are choosing a product, the safest bet based on available evidence is simply to match the trial conditions as closely as possible: about 3 grams per day of maca root powder, taken consistently for at least eight to twelve weeks. Whether you pick yellow, red, or black, raw or gelatinized, you are making a choice the science cannot currently inform with any confidence.

When Maca Is Probably Not the Answer

Low libido has many causes, and maca’s modest effects are unlikely to overcome all of them. If your loss of desire is driven by relationship conflict, chronic stress, depression, hormonal imbalances like clinically low testosterone or estrogen, sleep deprivation, or medication side effects beyond SSRIs, maca alone is not going to resolve the root issue. The trials that showed positive results for maca were conducted in people who were otherwise healthy, or whose sexual dysfunction was specifically attributed to antidepressant side effects.

The antidepressant angle is worth highlighting because it represents the most clinically relevant use case in the literature. SSRI-induced sexual dysfunction is extremely common, affects both desire and the ability to reach orgasm, and has few good treatment options. The fact that maca showed some benefit in this specific population, even modestly, is meaningful because the alternatives (switching medications, adding another drug, simply tolerating it) all come with their own trade-offs. If you are on an SSRI and experiencing sexual side effects, maca at 3 grams per day for a few months is a low-risk experiment worth discussing with whoever prescribes your medication.²

For people with no clear medical cause for low libido, the evidence is thinner. The trial in healthy men found an effect on desire, but these were men who were not complaining of low libido to begin with. Whether maca can restore desire that has faded for vague or multifactorial reasons is a question the current evidence does not clearly answer. It might, and the safety profile means trying it carries minimal downside, but you should go in with expectations set by the data rather than by marketing copy.

1
PubMed. Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men
2
PubMed Central. A Double-Blind Placebo-Controlled Trial of Maca Root as Treatment for Antidepressant-Induced Sexual Dysfunction in Women
3
CNS Neuroscience & Therapeutics. A Double‐Blind, Randomized, Pilot Dose‐Finding Study of Maca Root (L. Meyenii) for the Management of SSRI‐Induced Sexual Dysfunction
4
PubMed Central. Maca for improving sexual function: a systematic review
5
PubMed Central. Exploring the chemical and pharmacological variability of Lepidium meyenii: a comprehensive review of the effects of maca