Additionally, all studies examining the effect of maca on testosterone concentrations have previously been reviewed by Gonzales et al. (70) and were determined to not affect serum concentrations of testosterone. Overall, 9 out of 32 studies demonstrated significant increases in testosterone concentrations. The main findings of this review indicate that some herbs, particularly fenugreek seed extracts and ashwagandha extracts, have positive effects on testosterone concentrations in men. There were no statistically-significant increases in testosterone concentrations after 12 wk of supplementation in any of the trials. It has been shown to improve libido and sexual function independent of hormone changes. However, scientists need to study maca more extensively before recommending it for treating any health condition or symptom. However, various research studies have found noticeable positive effects after 12 weeks of maca use. However, a 2018 study examined a case of a woman whose blood lead concentration increased after she consumed a maca supplement. Limited evidence from animal research suggests that maca may have benefits for BPH, brain health, and skin health. Human research investigating the potential health benefits of maca is limited. While yellow maca is great for energy, red maca might lean more towards improving mood and balancing hormones. It was then that she stumbled upon maca root powder. From aiding memory to balancing hormone levels and even strengthening endurance, there’s a lot this root can potentially do. Originating from the high plateaus of the Peruvian Andes, Maca root has been consumed for centuries by indigenous people for its reputed health benefits. While this is just an anecdote, it does highlight the fact that Maca’s benefits might extend beyond just testosterone-related effects. This outcome was similar to that of an 8-wk study in 143 men (33–79 y) with erectile dysfunction, using a slightly higher dose (2 g/d) of tissue-cultured mountain (Asian) ginseng (root) extract (49), as well as another study using a longer intervention (12 wk, 3 g/d, Korean red ginseng; details of extract preparation not provided) in 60 men (26–70 y) with mild-to-moderate erectile dysfunction (37). Six studies used a randomized, double-blind, placebo-controlled study design (36–38, 47, 49, 56), and 1 study used a randomized, controlled crossover study design (65). All studies used berry or root extracts of Asian ginseng (Panax ginseng), with the root reported as Korean red ginseng, a processed form (67). Therefore, the aim of this systematic review was to summarize and critically evaluate randomized controlled trials conducted to assess the efficacy of single herbal ingredients on testosterone concentrations, in addition to their fractions or binding proteins, in men. Also, the studies on fenugreek used 4 different extracts, with dosages ranging from 250 mg/d up to 600 mg/d. For example, the studies on ashwagandha used dosages ranging from 240 to 675 mg/d, with varying standardization and extraction processes and different sample types. The heterogeneity of herbal extracts, various dosages used, and differences in sample types (serum, plasma, and saliva samples) make comparing studies and conducting a meta-analysis difficult. Only 6 out of 32 studies were assessed as having a low risk of bias due to their strong methodological study designs. This means that testosterone may have a greater physiological effect in the body when concentrations of these biomarkers are elevated.
