Maca: what it actually does, how much to take, and whether it is worth it

Maca gets sold as a bundle of everything at once: energy, libido, hormone balance, better training. The real picture is narrower — a couple of effects are decently studied, the rest is guesswork. Here is what the evidence shows, how much to take, and who it actually pays off for.

What maca is

Maca (Lepidium meyenii) is a root vegetable in the cruciferous family, grown between 3500 and 4500 metres of altitude in Peru. It has been eaten there for centuries as ordinary food, boiled or dried, in amounts of a few dozen grams per day. What you buy as a supplement is the dried, milled root — food in powder form, not an isolated active compound. Yellow, red and black varieties exist; red has been studied most for the prostate, black for sperm and memory, but the differences between them are nowhere near as firmly established as the labels suggest.

What the evidence shows

Libido — the strongest part of the story

This is the one area where results repeat across independent attempts. In several small randomised trials, 1500 to 3000 mg per day for 8 to 12 weeks raised self-reported sexual desire in men compared with placebo. The effect is moderate and measured by questionnaire, not by lab work. The important detail: it happened with no change in testosterone, estradiol or LH. So maca does not raise testosterone — it does something else, most likely through the central nervous system.

The second finding that repeated: in women on SSRI antidepressants who lost libido as a side effect, roughly 3000 mg per day for 12 weeks helped a portion of participants. Sample sizes were 30 to 50 people, so treat that as worth a try, not as treatment.

Sperm and fertility

A handful of small studies using 1500 to 3000 mg per day for 12 weeks found increases in sperm count and motility in healthy men. The trend is consistent, but the samples are small and most of the work comes from the same research group. If fertility is a real problem, a semen analysis and a urologist come before powder.

Menopause

Results are split. Some trials at 2000 to 3500 mg per day report fewer hot flushes and better mood; others find nothing beyond placebo. Hormones again do not move. A 12-week trial is reasonable if symptoms bother you, but do not expect anything close to hormone therapy.

Strength, muscle and endurance

This is the weakest area. There is one frequently cited study on eight cyclists showing a slightly faster 40 km time after 14 days — eight subjects, no replication, not a basis for a decision. There is no data showing maca improves 1RM, hypertrophy or recovery. If you want a supplement that measurably changes the gym, creatine monohydrate at 3 to 5 g per day and caffeine at 3 mg per kilogram of bodyweight about 45 minutes pre-training have evidence an order of magnitude stronger.

Energy and mood

Maca is not a stimulant: no caffeine, no rise in heart rate. The energy people report is subjective and often captured by the same questionnaires that measure mood. Not worthless, but do not compare it to coffee.

Dose, form and duration

Doses run into the thousands of milligrams, so it is easiest to count in grams:

• Amount: 1.5 to 3 g per day. Above 3 g there is no evidence of extra benefit.
• Timing: once daily with a meal, or two doses of 1.5 g. Time of day has not been shown to matter; food makes it easier on the gut.
• Form: gelatinised (heat-treated) powder digests more easily than raw. 500 mg capsules mean 3 to 6 capsules a day and cost more per gram than powder.
• Duration: the trials that found anything ran 8 to 12 weeks. If nothing has happened after 12 weeks, that is your answer.
• 10:1 extracts: there is no standardised active compound to convert the dose against, so comparisons with plain powder are unreliable. Stick to powder and grams.

How to test it on yourself

Start five things at once and you will never know which one worked. Add maca alone and keep everything else stable for 12 weeks: the same schedule (say 3 to 4 sessions per week), the same main lifts at 3 to 4 sets of 5 to 8 reps, the same bedtime give or take 30 minutes. Once a week write down two scores from 1 to 10 — libido and general energy — plus your working weights on two main lifts. At the end, compare the first three weeks with the last three. That is as close to a personal experiment as you get without a lab.

Side effects and when to see a doctor

Maca is generally well tolerated; the most common complaints are bloating, gas, and trouble falling asleep if taken late in the evening. Some situations, though, call for something other than powder first:

• Thyroid: maca is a cruciferous plant and contains glucosinolates. With existing thyroid disease or low iodine intake, check with a doctor before running 3 g a day for months.
• A sudden drop in libido alongside fatigue, strength loss and poor sleep needs bloodwork (morning testosterone, TSH, iron, glucose), not a supplement.
• Erectile dysfunction is often the first sign of a vascular problem. If it happens regularly, a cardiovascular check takes priority.
• Pregnancy and breastfeeding: no safety data at supplement doses — skip it.
• Hormone-sensitive conditions and treatments, including breast or prostate cancer therapy — ask beforehand, not after.

So is it worth it

Yes, but narrowly. If libido is your specific goal and you are willing to give it 12 weeks at 1.5 to 3 g per day, the chance of noticing something is real and the risk is low. If the goal is more weight on the bar, higher testosterone or alertness, your money does more in food, sleep and creatine. Maca is cheap, safe and modest; the problem only starts when people buy it expecting something else entirely.

The short version

• Dose: 1.5 to 3 g per day with food for 8 to 12 weeks; above 3 g there is no evidence.
• Strongest evidence: libido in men and women, including SSRI-related loss of desire.
• It does not change testosterone or estrogen, and there is no evidence for strength, muscle or recovery.
• Test it alone for 12 weeks with weekly notes; no effect means stop.
• See a doctor for: thyroid disease, sudden libido loss with fatigue, erectile dysfunction, pregnancy.