L-arginine and maca

L-arginine and maca are sold together on an energy- and vitality-adjacent shelf, but they're two very different things: an amino acid and a root vegetable. They're studied in completely separate literatures, and no dedicated trial testing the combination was found for this page.

Two different kinds of ingredient

L-arginine is an amino acid the body uses to build protein and make nitric oxide, among other things (see what is L-arginine). Maca (Lepidium meyenii) is a cruciferous root vegetable native to the Peruvian Andes, related to broccoli and radishes, and it's typically sold as a dried, ground powder or in capsules made from that powder. Beyond both being marketed on a general "vitality" theme, they don't share a mechanism, a food category or a research base.

What each one's own research measured

A 12-week, double-blind, placebo-controlled trial gave healthy men aged 21-56 either 1,500 mg/day or 3,000 mg/day of maca, or placebo. Starting at 8 weeks, the maca groups reported higher sexual-desire scores than placebo, an effect that showed up independently of changes in mood scores and without a measured change in testosterone or estradiol in either group. A separate, smaller open-label study with no placebo arm gave nine healthy men the same 1,500-3,000 mg/day dose range for 4 months and found increases in semen volume, sperm count and sperm motility, again without a measured hormone change.

L-arginine's own trial base covers different ground. A 2022 dose-response meta-analysis of 22 randomized trials found L-arginine supplementation associated with a mean decrease in blood pressure, with an identified effective dose starting around 4 g/day — see L-arginine benefits for that finding and its limits, and exercise and erectile-function-score research at other doses. None of it overlaps with the desire or semen-parameter outcomes maca's trials measured.

No study has tested L-arginine and maca together, at any dose, in any population.

Questions people ask

Can I take L-arginine and maca together?

No trial has tested the combination, so there's no research describing an added or combined effect. Each ingredient has its own separate dosing and safety profile — see L-arginine dosage for arginine's — and checking with a doctor before combining any two supplements is a reasonable step if you take medication.

Is maca better than L-arginine?

They're not interchangeable, so "better" depends on which outcome you mean. Maca's trials measured self-reported sexual desire and semen parameters in healthy men; L-arginine's measured blood pressure, exercise performance and erectile-function scores. This page doesn't rank the two against each other, since they've never been compared head-to-head in a trial.

Related reading: what is L-arginine, L-arginine benefits: what the research does and doesn't show, and L-arginine dosage.