Maca powder: good for your libido, not for your testosterone

Maca powder raises your libido, but not your testosterone. In two Peruvian trials from 2002 and 2003, sexual desire rose from week 8. Testosterone and estradiol did not move a millimetre (Gonzales 2002, PMID 12472620). That is the whole story in two sentences.

What strikes me as a training partner? Almost every page about maca powder calls it a hormone booster. The researchers who first tested it in people found exactly the opposite.

Below is what maca does do and at which dose that was measured. And which blood values to look at if low libido is your complaint.

What is maca powder?

Maca (Lepidium meyenii) is a root vegetable from the Peruvian Andes. It grows at around 4,000 metres and has been eaten there for centuries. The powder is the dried, ground root.

You buy it as yellow, red or black maca powder, and as capsules. It is a food, not a concentrated herbal extract. That makes the dosing generous: the trials used 1,500 to 3,000 mg a day.

The taste is earthy and slightly sweet. Plenty of athletes stir it into porridge or a shake. That is fine, as long as you know what to expect from it.

Which is less than the packaging promises.

What does maca powder do?

The effect of maca powder on libido has been measured in people, and it was real. In the Gonzales trial, men aged 21 to 56 took maca or a placebo for twelve weeks. The dose was 1,500 or 3,000 mg a day. From week 8, the maca group reported more sexual desire (Gonzales 2002, PMID 12472620).

Both doses worked equally well. More maca did not mean a bigger effect. Desire rose independently of mood and anxiety, which the researchers measured separately.

What maca did not do: touch your hormones. Testosterone and estradiol stayed flat. In the follow-up study a year later, LH, FSH and prolactin stayed flat too. So did 17-OH progesterone (Gonzales 2003, PMID 12525260).

A supplement that raises your desire without touching your hormones. That is rare, and it is exactly why maca stays interesting.

What are the effects of maca?

Beyond libido the evidence is thin. There are small studies on sperm quality, mood and endurance, most with fewer than 30 participants. None has been repeated in a large group.

EFSA has not authorised a single health claim for maca. A seller is therefore not allowed to claim that maca raises your testosterone or improves your performance. If they do, you know enough about that seller.

The Dutch Voedingscentrum puts it plainly. People who eat a healthy, varied diet do not need supplements as a rule. Maca falls under that too.

What does maca do in women?

In women, maca has mostly been studied around menopause and for low libido caused by antidepressants. The studies are small and the results vary. In women too, hormone values did not change in those trials.

So for a woman who trains, the same applies as for a man. Maca is a libido supplement, not a hormone supplement.

What are the negative effects of maca?

Maca was well tolerated in the trials. The most reported complaints are bloating and wind, especially with raw powder. Gelatinised powder, which has been heated, causes less of that.

Because maca does not touch your hormones, there is no reason to fear rising estradiol or prolactin. The biggest negative effect is an empty wallet, if you bought it to raise testosterone.

If you take thyroid medication, check with your GP. Maca contains goitrogens, substances that could in theory slow iodine uptake. At normal amounts that has not been shown in practice.

Low libido: what to measure before you start on maca

Low libido has a measurable cause more often than people think. Imagine you are 34, train four times a week, and your desire has been gone for months. Maca might bring the desire back, but it hides the cause.

So my line as a training partner: I would want to know where I stand first. Only then take something. These values tell you the most.

Total testosterone, free testosterone and SHBG come together in the hormone panel. The other values are measured separately via the biomarker pages. If you only want the baseline number, the testosterone test is enough.

Have blood drawn in the morning, between 7 and 10. Fasting is usually not needed for testosterone. Testosterone peaks then, and most labs base their reference values on that moment. An afternoon reading gives a lower number that says little.

If your testosterone is low, maca will not fix that. Read how free testosterone and SHBG relate, and what a low number does and does not mean.

What you can do with this

My line: maca is one of the few supplements with an honestly measured effect. That effect is libido. Expect nothing from your hormones and you will not be disappointed.

If you want to know whether it works for you, measure your values before you start. Measure again after 8 to 12 weeks, at the same time of day. If your desire changes but your testosterone does not, you saw exactly what the trials saw.

Other supplements assessed the same way are in testosterone supplements: what works and what your blood shows. Tribulus often sits next to maca on the shelf. It is covered in tribulus terrestris: what it does.

If a value is off, discuss it with your GP and mention which supplements you take. Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

References

• Gonzales GF, Córdova A, Vega K, et al. Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men. Andrologia. 2002 (PMID 12472620).
• Gonzales GF, Córdova A, Vega K, et al. Effect of Lepidium meyenii (Maca), a root with aphrodisiac and fertility-enhancing properties, on serum reproductive hormone levels in adult healthy men. J Endocrinol. 2003 (PMID 12525260).
• Pilz S, Frisch S, Koertke H, et al. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011 (PMID 21154195).
• Travison TG, Vesper HW, Orwoll E, et al. Harmonized reference ranges for circulating testosterone levels in men of four cohort studies in the United States and Europe. J Clin Endocrinol Metab. 2017 (PMID 28324103).
• Voedingscentrum. Voedingssupplementen. voedingscentrum.nl.
• EFSA. EU Register of nutrition and health claims. ec.europa.eu/food/safety/labelling_nutrition/claims/register.