Maca: The Andean Root for Libido, Energy, and Mood

At an altitude of over 4,000 meters in the Peruvian Andes, where almost no edible plant survives the cold, radiation, and thin air, a small turnip-shaped tuber has been growing for thousands of years. The Incas called it 'food of the warriors' and believed it granted strength, fertility, and endurance. Today, centuries later, that same tuber has become one of the best-selling dietary supplements in the world under one simple name: Maca.

The marketing promises a lot: explosive libido, energy of a 20-year-old, and perfect hormonal balance. But what does science really say? Unlike most anti-aging supplements, maca has reasonable evidence from humans, not just mice, and that is exactly why we rated it yellow and not red. The big surprise you will discover later: maca's effect on libido and mood likely does not work through sex hormones at all.

What is Maca?

Maca (scientific name Lepidium meyenii, and sometimes Lepidium peruvianum) is a plant from the Brassicaceae family, the same family as broccoli, cabbage, and radish. The edible part is the tuber, which is ground into powder. Here is what is important to know about it:

• Origin: Grows only in the highlands of the Peruvian and Bolivian Andes, under extreme conditions of altitude and cold.
• Different colors: There is yellow maca (the most common), red, and black. The color is not just cosmetic; studies indicate differences in effect: black maca has been studied more for memory and sperm, red for prostate health.
• Composition: Rich in protein, fiber, minerals (iron, zinc, calcium), and unique molecules called macamides and glucosinolates, which are considered the active components.
• Classification: Sometimes classified as an 'adaptogen,' a plant that helps the body cope with stress, but this is a marketing label that is not well scientifically established.
• Form of use: Sold as powder, capsules, or in a 'gelatinized' form where the starch is broken down to improve absorption and digestion.

The Surprising Mechanism: Not Through Testosterone

The critical point, and what differentiates maca from supplements that claim to raise testosterone: Maca does not increase blood levels of testosterone or estrogen. Studies that measured sex hormones before and after taking maca found no change in levels of estradiol, testosterone, FSH, or LH.

So how does it affect libido and mood? Current scientific hypotheses point to several non-hormonal pathways:

• Central nervous system: The unique macamides in maca may affect the neurotransmitter system, including dopaminergic pathways related to desire and motivation.
• Reducing anxiety and depression: Improvement in mood and sense of well-being directly translates to an increase in sexual interest, independent of hormones.
• Cellular energy and endurance: A rich nutritional composition that supports mitochondrial function and overall vitality.
• Antioxidants: Glucosinolates and polyphenols provide antioxidant activity that protects cells from oxidative stress.

The practical implication: Those looking to hormonally raise testosterone will not find it in maca. But those looking for improvement in desire, energy, and mood may actually benefit, and precisely because the mechanism is non-hormonal, its safety profile is better than hormonal supplements.

Current Evidence

Study 1: Systematic Review of Maca and Sexual Function from 2010

The most important review in the field was published in the journal BMC Complementary and Alternative Medicine in 2010 by Shin et al. The researchers scanned 17 databases and identified 4 randomized placebo-controlled trials that tested maca for improving sexual function. The results: Two studies showed a significant positive effect on sexual desire in healthy men and on sexual function in menopausal women. Another study showed a significant improvement in men with erectile dysfunction. One study showed no effect in cyclists. The researchers' conclusion: Limited but encouraging evidence, with a need for larger studies.

Study 2: Maca, Anxiety, and Depression in Menopause from 2008

A study published in the journal Menopause in 2008 tested 14 postmenopausal women in a randomized, double-blind, placebo-controlled crossover design. The women took 3.5 grams of maca per day for 6 weeks versus placebo. The result: A significant decrease in symptoms of anxiety and depression, and an improvement in measures of sexual function, according to the Greene Climacteric Scale. The crucial finding: Blood tests showed zero change in levels of estradiol, FSH, and LH, meaning the effect was independent of estrogenic or androgenic activity. This is one of the most important studies demonstrating the non-hormonal mechanism.

Study 3: Maca, Depression, and Blood Pressure from 2015

A randomized double-blind study published in the journal Climacteric tested 29 Chinese postmenopausal women who took 3.3 grams of maca per day versus placebo, each for 6 weeks in a crossover design. The results: A decrease in depressive symptoms and an improvement in diastolic blood pressure. The study reinforced the link between maca and mood improvement in a different ethnic population, although the researchers noted it was a small pilot study.

What About Energy and Fertility?

Beyond libido and mood, maca has also been studied in other contexts. In the field of male fertility, several small studies showed an increase in semen volume, sperm count, and sperm motility in healthy men taking maca, though again, without a change in sex hormones. In the field of energy and endurance, the evidence is weaker: the study on cyclists showed no improvement in performance, so the feeling of 'energy' that users report is likely more related to improved mood and sleep than to a direct improvement in physical fitness. This is an important distinction: maca is not a stimulant like caffeine; it works gently and over time.

Should You Start Taking Maca?

This is where sobriety comes in. Despite the positive evidence, there are several caveats to be aware of:

• Small sample sizes: The main studies included only 14 to 29 participants. This is far from the scale of thousands of participants needed for full certainty.
• Moderate methodological quality: The systematic review itself noted that the quality of the studies is limited, and that larger, higher-quality studies are needed.
• Effect on the thyroid: Maca contains glucosinolates, which in very large amounts may interfere with thyroid function. Anyone suffering from hypothyroidism should consult a doctor.
• Hormone-sensitive cancers: Although maca is not hormonal, those with a history of breast or prostate cancer should exercise caution and seek medical advice before use.
• Cost and time: The effect is not immediate; most studies measured it after at least 6 weeks. Expect a cost of 50 to 120 shekels per month for a quality supplement.

On the other hand, maca's safety profile is among the best in the supplement world. At a dosage of 1.5 to 3 grams per day, almost no significant side effects have been reported, and it is an edible tuber that has been eaten in Peru for thousands of years.

What to Take Away from the Research?

1. If you are looking to improve libido or mood, maca is a reasonable experiment. At a dosage of 1.5 to 3 grams per day, with realistic expectations and not magic, and after 6 to 8 weeks of consistent use.
2. Do not expect an increase in testosterone. If that is your goal, maca is not the right tool. It works through a completely different, non-hormonal mechanism.
3. Choose a quality form: Gelatinized maca is better absorbed and less taxing on digestion. Black for memory and sperm, red for prostate.
4. Start with a low dose: Start with 1.5 grams and increase gradually to check personal response.
5. Consult if you have a thyroid issue or hormonal sensitivity: This is the main medical caveat.

You can purchase quality maca at a reasonable price through purchase maca on iHerb. And if you want to check which supplements are exactly right for your goals, it is worth going through our personal supplement selector.

The Broader Perspective

Maca is an excellent example of a supplement that sits in the middle, neither magic nor a scam. The evidence is real but limited, the effect is moderate but consistent, and the safety profile is excellent. This is exactly what justifies the yellow rating: not a supplement everyone must take, but also not one to avoid.

The most important lesson from maca is actually about the mechanism: It improves libido and mood without touching sex hormones at all. This is a reminder that our bodies are much more complex than testosterone or estrogen, and that plant molecules can act through pathways we still do not fully understand. Instead of chasing the next 'testosterone booster,' perhaps it is worth remembering that sometimes a small tuber from the Andes, growing where nothing else survives, knows how to do the job gently.

References:
Brooks NA et al., Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women are not related to estrogen or androgen content, Menopause, 2008
Shin BC et al., Maca (L. meyenii) for improving sexual function: a systematic review, BMC Complementary and Alternative Medicine, 2010
Stojanovska L et al., Maca reduces blood pressure and depression in a pilot study in postmenopausal women, Climacteric, 2015