Ingredient deep-dive

Maca At 1,500 mg Did Nothing. At 3,000 mg It Did.

One double-blind trial ran two doses of maca against each other at the same time, in the same people, for the same twelve weeks. The higher arm improved and the lower arm did not. That is the closest thing this whole category has to a threshold, and it is worth more than a dozen single-dose studies.

By HoneyPower Team · Medically reviewed by Dr. Sevann Helo, MD · Revised September 30, 2026 · 8 min read · Ingredient deep-dive

The trial that ran two doses at once

the dose-finding study where 1.5 g did nothing and 3 g did is a double-blind, randomised, pilot dose-finding study. The subject was sexual dysfunction associated with SSRI antidepressants, and the design is what makes it valuable well beyond that context: it ran a 1,500 mg daily arm and a 3,000 mg daily arm alongside each other.

The higher arm produced a measurable improvement. The lower one did not.

Almost nothing else in this category does that. The normal pattern is a single dose against placebo, which tells you whether that dose worked and nothing about what would have happened at half of it. A trial that tests two doses in the same population at the same time hands a reader a threshold, and a threshold is directly usable when you are looking at a number printed on a panel.

Five studies and one number keeps recurring: three grams a day. The first row is the only one in the whole category built to find out what happens below it.

What the twelve-week desire trials found

the 12-week desire trial ran twelve weeks in adult healthy men at 1,500 and 3,000 mg a day and reported improved sexual desire. The detail worth carrying away is the timing: the effect appeared at around week eight rather than in the first fortnight.

the systematic review of four trials pooled four randomised trials and described the evidence as limited but suggestive, which remains a fair summary. Four small trials is a thin base, and the review authors said so.

a 175-person trial of the spray-dried extract is the largest of the modern studies, testing black and red maca extracts in 175 people living at altitude over twelve weeks, and reporting acceptable safety alongside modest effects on the measures it took.

The hormone paper nobody quotes

the companion hormone paper is the companion to the desire trial. The same research group measured serum reproductive hormones in the same participants over the same twelve weeks, and reported them unchanged.

This is the paper that gets left out of marketing copy, and leaving it out changes what the first paper means. Desire moved. Testosterone, luteinising hormone and the rest of the panel did not.

So maca is not a testosterone story, whatever a box implies by putting it in a formula alongside tribulus. Whatever it is doing, it is doing it by some route nobody has pinned down, and honest writing about it says that rather than borrowing a mechanism from a neighbouring ingredient.

The four-month study, and why it is separate

the four-month semen study ran longer than the others, at four months, and measured semen parameters in adult men at the same 1,500 and 3,000 mg doses. It reported improvements, and once again without a hormone change to explain them.

It is listed separately here because fertility and desire are different outcomes with different clinical meanings, and a page that blurs them is doing the reader no favours. A supplement is not a fertility treatment, and this study is not evidence that it is one. What it adds is a third independent measure moving in the same direction on the same plant.

Root powder, extract, and why the ratio decides everything

Every dose above is a dose of maca root material. That matters because the gap between a trial and a panel is often bridged, legitimately, by concentration.

A 10:1 extract is made by processing ten grams of raw material down to one gram of extract. If the ratio is honest and the constituents survive the process, 300 mg of a 10:1 extract is arguably standing in for 3,000 mg of root. That is a real argument and some labels are entitled to make it.

The condition is that the label has to print the ratio. Without it, a small number on a panel is just a small number, and the reader has no way to tell whether they are looking at a concentrated extract or a tenth of a working dose.

Only the fourth row is an argument a label can make. It has to print the ratio to make it.

Reading a maca row against 3,000 mg

Three grams a day is the number to carry. It is what worked in the dose-finding trial, it is the upper arm of the desire trials, and it is the upper arm of the semen study. It recurs because the same research group used it repeatedly and because it is the dose that kept producing results.

One and a half grams is the second most useful number, and it is useful precisely because it failed. A documented negative at a stated dose is rare in supplement research, and it sets a floor a reader can reason from.

Put a panel beside those two figures and most maca rows in this aisle sit well below both, with no extract ratio offered to close the distance. That is not a reason to avoid maca. It is a reason to be realistic about what a small unstandardised row is likely to be contributing.

Why eight weeks is the number to plan around

Every study above ran twelve weeks or longer, and the desire trial's effect appeared around week eight. Nothing here acts in days.

That has a practical consequence for anybody trying a formula containing maca. A judgement made at two weeks is a judgement about nothing, and a bottle abandoned at three weeks was never given the span its own research used. The distributor's stated typical wait for this product is 3–4 weeks, which is broadly consistent with the literature.

It also means a long refund window is worth more than it looks. A thirty-day guarantee expires before the research says the ingredient would have shown anything.

Four questions worth asking of any maca row

1. How much? Three grams a day worked and one and a half did not, in the one trial built to find out.
2. Root powder or extract? If extract, at what ratio. Without a ratio the comparison cannot be made.
3. Black, red or yellow? The 2016 study tested black and red separately. Most labels do not say.
4. Am I expecting a hormone change? Two studies measured hormones on maca and neither found one. Expect what the trials found rather than what the box suggests.

References