Maca Root, Libido, and Energy

This result is worth highlighting, since it contradicts the most popular explanation circulating online about maca — that it works "hormonally," by raising testosterone. The study by Gonzales and colleagues, one of the few specifically designed to test this, showed the opposite: the effect on sexual desire appeared without any measurable change in testosterone or estradiol levels. This means that if maca genuinely does affect libido, it does so through a non-hormonal mechanism that has not yet been fully explained.

Maca supplement marketing almost always combines two claims in one sentence: "improves libido and boosts energy." Yet these are two entirely different levels of evidence. While real, randomized studies with a specific numerical result exist for sexual desire, the clinical evidence for "energy" — in the sense of general arousal, reduced perceived fatigue, or improved physical performance — is far more modest, largely limited to sports-performance studies that failed to confirm the effect convincingly, plus traditional use and subjective accounts rather than dedicated, well-designed studies on fatigue.

This doesn't mean maca definitely has no effect on perceived energy in anyone — but it does mean the "energy" claim today rests mainly on tradition, marketing, and isolated, unconfirmed observations, rather than on the same quality of evidence as the libido claim. It should honestly be labeled a hypothesis, not a confirmed effect.

Maca contains a group of compounds unique to this species called macamides and macaenes — fatty acid amides not naturally found in any other commonly consumed plant. Most of the described effects are attributed to them, though the exact mechanism by which they act on the central nervous system or sexual desire has not yet been fully explained at the molecular level in humans.

Since the Gonzales et al. study ruled out a hormonal mechanism (no changes in testosterone or estradiol), and the effect didn't result from a mood change either, what remains are hypotheses about a direct effect on brain structures involved in regulating sexual desire, or on vascular endothelial function and blood flow — similar mechanisms are sometimes studied in the context of erectile dysfunction. None of these hypotheses currently holds the status of a confirmed mechanism — this is an area of active preclinical research, mostly in animal models, which should not be confused with evidence of an effect in humans.

Maca is sold in several forms differing in processing method and root color. Most of the clinical studies cited here, including Gonzales', used so-called gelatinized maca — a form pre-treated with heat to remove starch, which is meant to improve digestibility and absorption compared with raw, dried whole-root powder.

Maca belongs to a small group of "libido" supplements that have real, randomized clinical trials behind them, rather than tradition and marketing alone — this sets it apart from many competing products in the same category. At the same time, it's worth separating this specific, relatively well-documented promise from the far more weakly supported "energy" claim, which is almost automatically tacked on in marketing materials despite the available data not directly confirming it.

Anyone considering maca supplementation should have realistic expectations: any effect, if it appears, is likely to be moderate and require several weeks of regular use, rather than immediate and dramatic. It's also worth remembering that the scale of available research is still small — this doesn't disqualify maca as a supplement, but it does justify keeping proportion between what the data show and what the label promises.