There is no gelatin in gelatinized maca; rather; the starch in gelatinized maca powder has undergone a chemical transformation referred to as gelatinization. Regular maca powder has to be extensively processed to become gelatinized maca. Maca powder is mixed with water, exposed to high-pressure conditions, and then dried and pulverized. Gelatinized starches are more easily digestible, and scientists theorize that this increases maca’s bioavailability.^{[10] [11]} However, it is unknown whether different maca preparations have different therapeutic effects.

Potentially bioactive ingredients that are unique to maca include macaridine, macaenes (fatty acids), macamides, and maca alkaloids. Maca contains glucosinolates, such as glucoalyssin, glucosinalbin, glucobrassicanapin, glucobrassicin, glucoaubrietin and benzyl glucosinolate. Maca also contains sterols, such as beta-sitosterol, campesterol, and stigmasterol. The amounts of these ingredients vary between different growers, different colors, and different batches of maca. Although mechanisms of action are largely unknown, some theorize that these ingredients may play a role in maca’s purported effects on fertility (reproductive health), sexual drive, hormonal balance, and immune function.^[12][13]

Although there are no known drug interactions with maca, a comprehensive drug interaction study has not been conducted. In vitro evidence suggests that aqueous and ethanolic maca extracts have some estrogenic activity.^[7] However, it is unclear if this estrogenic activity translates to humans. Some clinical research suggests that gelatinized maca increases estradiol levels compared to placebo, while other clinical research shows no effect on hormone levels.^{[8] [4]} Therefore, it’s unknown whether maca might interfere with hormonal drug therapy. Maca does not seem to have the potential to affect drug metabolism through the liver. An in vitro screening study did not find that maca extracts are likely to inhibit or induce cytochrome P450 enzymes in the liver, but further research is needed to confirm these findings.^[9]

Because of the potential estrogenic properties of maca, there are safety concerns regarding its use by individuals with a history of estrogen-dependent cancers, such as some types of breast cancer.^[7] While direct research on maca's effects in individuals with a history of breast cancer is limited, in vitro studies conducted on breast cancer cell lines have had mixed findings.

For instance, one in vitro study found that maca extract had no effect on MCF-7 (breast cancer) cell lines. However, it was also observed that macamides (a class of amide alkaloids found in maca) showed inhibitory effects similar to those of cisplatin (a chemotherapy drug) on five cancer cell lines, including MCF-7. Additionally, other studies have reported strong anticancer effects of benzyl isothiocyanate (BITC; a breakdown product of maca glucosinolates) in human breast cancer cells and in mice.^[14][15][16]

Conversely, a 2022 study found that although maca root extract exhibited toxicity towards triple-negative breast cancer (TNBC) cell lines (which is potentially beneficial in reducing tumor cell viability), it also increased the migratory capacity of cancer cells and caused gene expression changes that might promote cancer progression.^[17]

Given these mixed findings, until more conclusive evidence is available, it may be prudent for individuals with a history of estrogen-dependent cancers or people concerned about breast cancer to approach maca supplementation with caution.