Maca Side Effects and Safety: What You Need to Know
Maca (Lepidium meyenii) is a root vegetable native to the Peruvian Andes that has been cultivated and consumed as food for thousands of years. As a supplement, it is often marketed for energy, libido, and hormonal support. But what does the evidence say about maca safety, and are there meaningful risks to be aware of?
Common and Rare Side Effects
Maca is generally well tolerated in healthy adults when used at typical supplemental doses. The most commonly reported issues are mild gastrointestinal discomfort — bloating, nausea, or loose stools — particularly when starting with higher amounts or taking maca on an empty stomach. Gelatinised maca (pre-cooked) is easier on the digestive system than raw maca powder for most people.
Some users report changes in mood, sleep, or energy levels during the first few weeks of use. These effects are usually transient and resolve as the body adjusts.
There are anecdotal reports of maca increasing thyroid volume due to its glucosinolate content (plant compounds also found in broccoli and cabbage), which theoretically could be a concern for people with thyroid disease who also have low iodine intake. The clinical significance of this in humans at typical supplement doses is not established by strong evidence.
Upper Safe Limits
Maca does not have a formally established tolerable upper intake level from a regulatory body. Most clinical trials studying maca safety in adults have used doses in the range of 1.5 to 3 g of dried maca root per day for periods of six to twelve weeks without serious adverse events (Gonzales et al., 2002). Long-term safety data beyond a few months are limited.
Because maca has been consumed as a food staple in the Andes for centuries, it is generally considered to have a favourable safety profile at food-equivalent quantities.
Drug and Nutrient Interactions
Formal pharmacokinetic studies of maca interactions with medications are very limited. Based on its proposed mechanisms:
- Hormone-sensitive conditions: Maca is often claimed to influence sex hormone levels, though the evidence is mixed. Gonzales et al. (2003) found in a randomised trial that maca supplementation did not alter serum testosterone or oestradiol levels in men, suggesting the popular "hormonal" claims require more scrutiny (Gonzales et al., 2003).
- Anticoagulants: No direct interaction data are available; caution is prudent given the general principle of monitoring supplements alongside blood thinners.
- Thyroid medications: Theoretically, glucosinolates at very high intake could interfere with thyroid function; practical risk at standard supplement doses appears low.
If you are taking prescription medications, discuss maca use with your physician.
Who Should Be Cautious or Avoid Maca
- Pregnant and breastfeeding women: Safety data in pregnancy are absent; maca has been consumed as food in Peru but systematic studies are lacking.
- People with hormone-sensitive cancers (e.g., breast, uterine, prostate): Until the hormonal effects of maca are better characterised, caution is warranted.
- Thyroid disease with borderline iodine status: If dietary iodine is very low, high-dose maca (particularly raw) may theoretically be goitrogenic.
- Children: No safety data exist for paediatric use.
Quality and Contamination Concerns
Maca products on the market range from whole-root powder to extracts standardised to specific compounds. Key quality issues:
- Adulteration and origin: Cheaper products may blend Peruvian maca with other root powders. Genuine Peruvian origin and supply-chain documentation matter.
- Heavy metals: Root vegetables can accumulate heavy metals from soil. Choose brands that perform third-party heavy-metal testing.
- Gelatinised vs. raw: Gelatinisation (heating) removes starch, reduces goitrogens, and improves digestibility without meaningfully altering the active compounds.
At maxfit.ee you will find options including NOW Maca 500mg 250 veg. caps., Ostrovit Maca 90tab, BIOTECHUSA Maca 60 caps, and ICONFIT Maca 90caps — browse the maca category for the full selection.
FAQ
Does maca raise testosterone levels?
Despite popular belief, clinical trials have not consistently demonstrated that maca raises serum testosterone. Gonzales et al. (2003) found that men taking maca for 12 weeks showed improved sexual desire without detectable changes in testosterone or oestradiol. The mechanism appears to operate independently of classical sex hormone pathways.
How long does it take for maca to work?
Most research showing effects on sexual function and subjective energy used supplementation periods of four to twelve weeks. Short-term use of a few days is unlikely to produce noticeable changes.
Can I take maca every day?
Short-term daily use at doses around 1.5 to 3 g appears safe based on available trials (Gonzales et al., 2002). Very long-term continuous use has not been adequately studied; cycling (e.g., five weeks on, one week off) is a common practice among users, though not evidence-mandated.
References
Gonzales, G. F., Cordova, A., Vega, K., Chung, A., Villena, A., Gonez, C., & Castillo, S. (2002). Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men. Andrologia, 34(6), 367-372. https://pubmed.ncbi.nlm.nih.gov/12472620/
Gonzales, G. F., Cordova, A., Gonzales, C., Chung, A., Vega, K., & Villena, A. (2003). Lepidium meyenii (Maca) improved semen parameters in adult men. Asian Journal of Andrology, 5(4), 349-352. https://pubmed.ncbi.nlm.nih.gov/14695987/
Zavatta, G., & Clarke, B. L. (2021). Nonclassical actions of calcium-sensing receptor: how to survive in a changing environment? Endocrine Reviews, 42(3), 322-342.
