Maca is an interesting little root. The Peruvian plant only grows in the most inhospitable parts of the Andes, yet it’s becoming popular worldwide as an aphrodisiac and fertility booster. It also has a decent nutritional profile — it’s a good source of vitamin C, iron, potassium, and copper, and it has a fair amount of B vitamins. Maca comes in several shades, and the darker roots are high in tough-to-find iodine.

Maca’s earthy butterscotch taste means it pairs nicely with chocolate and disappears into smoothies. There’s been a decent amount of research on maca for sex drive and libido, with interesting results. Here’s a closer look at what maca root does, along with a few thoughts on when and how to eat it.

Maca may boost sex drive…we’re just not sure why

Unlike powdered rhinoceros horn, dried tiger penis, and most other traditional aphrodisiacs, maca actually seems to work. There’s some evidence to back up claims of its sex-enhancing properties. Here’s what the science says about maca.

Scientific studies on maca root

In a double-blind 2002 study, researchers gave 57 men either 1.5g maca, 3g maca, or placebo. The men received the supplements daily for 12 weeks. After 8 weeks, men in the two maca groups reported heightened sexual desire.[1]

Another study looked at 20 depressed men on SSRIs – antidepressants that often decrease sex drive – and found that 3g of maca daily significantly increased self-reported libido, although 1.5g of maca did not.[2] A similar study looking at 45 women on antidepressants found maca had the same effect.[3]

A fourth study of 8 endurance athletes found that maca extract (the equivalent of 10g/day maca) increased self-reported sexual desire (though it did not improve endurance training).[4]

These studies were small and they relied on self-reporting. That said, they were also all double-blind, placebo-controlled, and randomized, and each one showed the same pattern of results: maca increased libido. Add in a 2001 study showing that both 1.5g and 3g of daily maca increased sperm count and sperm motility,[5] plus another one showing that it improved erectile dysfunction,[6] and it seems like there may be something to the claim that maca is an aphrodisiac.

What makes maca so interesting is that we still don’t understand why it increases sex drive. Sex drive usually links to sex hormones, though with maca that doesn’t seem to be the case. Researchers have measured testosterone and estrogen levels of people taking maca and found no changes, even when the participants reported increased libido.[7]“]

Maca root side effects

There aren’t many side effects when taking maca root, and you can easily avoid them if you know how to take maca root. Here are a couple potential side effects and how to avoid them.

Brain fog and sluggishness

Maca root gets moldy. Traditionally, Peruvians dry maca root and crush it into a powder. Dried maca powder is what you’ll typically find in health food stores as well. The trouble is that maca often grows mold during the drying process, and the resulting powder often contains aflatoxin, a potent carcinogen. Maca was on the drawing board as a Bulletproof product for a while, but it was difficult to find a pure source; even the highest quality maca root contained about 13 ppb aflatoxin. That’s not up to Bulletproof standards.

If you buy maca, get it from a high-end brand, and if you take it and you feel sick or foggy afterward, consider that your discomfort could be due to a moldy batch and not maca root itself.

How to avoid ingesting mold toxins in maca root

There are two options that will reduce your mold exposure when taking maca:

Buy whole maca root and soak it overnight to wash away some of the mold toxins. Opt for an extract or tincture instead of a powder. Extracts are made by soaking the fresh root in alcohol for a few weeks, and molds aren’t able to grow.

Another maca side effect: thyroid problems

While maca looks and tastes like a root, it’s actually a cruciferous vegetable, which is the same category as cauliflower, kale, cabbage, Brussels sprouts, and other members of the Brassica family. And like other cruciferous veggies, maca contains goitrogens, anti-nutrients that disrupt thyroid hormones. There are two ways to reduce goitrogens in maca root.

1. Cook whole maca

While goitrogens are bad news, they don’t stand up to heat well. That means you should always cook your maca (and your cauliflower, kale, cabbage, etc.). If you find maca root whole, you can bake or boil it and then make it into a mash, the way you would prepare potatoes.

2. Choose gelatanized maca powder

If you buy powdered maca, skip the raw variety and instead go for gelatinized maca. Despite its name, gelatinized maca isn’t gelatinous. It’s still a powder, and it will still mix into most dishes well; the gelatinization process just removes antinutrients, proteins, and starches. It seems to leave maca’s aphrodisiac properties intact.

How to use maca powder

Maca has a malty, nutty, slightly sweet flavor that pairs well with chocolate and vanilla, so it’s a great addition to smoothies or protein shakes. You could even spoon some into your morning coffee, although the high starch content may take you out of ketosis. However you take it, be sure your maca’s cooked, and get the high-quality stuff to avoid mold toxins as much as possible.

Maca powder dosage

To use maca powder, mix one teaspoon, which is roughly 5g, into your smoothie or protein shake.

You can also get powdered maca in capsule form, which will be measured for you. Capsule sizes differ, so follow the package directions.

Scientists gave test participants 3g of maca a day for three months with no adverse effects. Plus, only potatoes and maca are able to grow in the highlands of Peru, so the locals eat a serving or more almost every day. It’s generally safe as a food and as an herbal supplement.

Do you have a favorite brand of maca? Have you felt any effects from taking it?