One randomized, double-blind, placebo-controlled study was conducted examining the effects of a garcinia extract (standardized to contain 60% hydroxycitric acid; details of extraction process not provided) on testosterone concentrations (43). One randomized, double-blind, placebo-controlled study was conducted examining the effects of a rhodiola extract (standardized to 3% rosavins) on testosterone concentrations (46). Participants supplemented with 2.4 g of maca (pulverized, dehydrated maca root) daily did not increase testosterone concentrations compared with the placebo group. This product also claims to make use of potent ingredients that help promote antioxidant activity in the prostate which helps the prostate in a big way. In some advanced cases prostate cancer results and this adversely affects a man’s quality of life. In this condition, the prostate tends to enlarge and place pressure on the bladder. One randomized, double-blind, placebo-controlled study was conducted examining the effects of a longjack extract (Physta®, manufactured by Biotropics; freeze-dried water extract) on testosterone concentrations (45). One randomized, double-blind, placebo-controlled study was conducted examining the effects of reishi extract (dried and chipped with 30% ethanol) on testosterone concentrations (55). Twelve weeks of daily supplementation with 1667 mg of garcinia, equivalent to 1000 mg of hydroxycitric acid, in 25 overweight or obese men aged between 20 and 65 y did not significantly increase testosterone concentrations compared with men in the placebo group. 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. This meta-analysis included 4 studies (42, 58, 63, 64) but did not include 2 of the studies included in this review because it was conducted in late 2018 and excluded studies with a duration 69) conducted a systematic review on all tribulus studies examining various forms of testosterone in animals and humans and concluded that the evidence indicated that it is ineffective at increasing testosterone concentrations in humans. Overall, 9 out of 32 studies demonstrated significant increases in testosterone concentrations. Four studies (39, 48, 54, 61) examined the effects of Tribulus terrestris on testosterone concentrations. The 1 study that showed no effect of an ashwagandha extract, Shoden®, on testosterone concentrations in men was conducted by Lopresti et al. (51). Four studies were conducted examining the effects of ashwagandha on testosterone concentrations (35, 50, 51, 62). This may lead to a decreased sensitivity of the prostate to androgens, which can improve symptoms of benign prostate hyperplasia. This may be due to the presence of polysaccharide fractions in the root. These include reducing inflammation, relieving allergies, increasing free testosterone, and regulating blood sugar and pressure. The initial search identified 4384 unique studies, of which 32 randomized controlled trials were identified as eligible following assessment using the selection criteria (Figure 1) (35–66). FT or BT (the combination of FT and albumin-bound, "weakly-bound" testosterone) have been suggested as more effective measures for diagnosing AD, particularly as men age (32). The inclusion of the testosterone fractions and binding proteins were deemed important since only ∼2% is "free" testosterone, with the remaining testosterone "bound" to proteins (predominantly SHBG, ∼40–45%) (31–33) and controversy existing regarding the relative importance of "bound" and "unbound" testosterone (34). Testosterone, its fractions, and binding proteins were all examined in this systematic review. Risk of bias of the included studies was assessed using the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials (30). NOW Foods Prostate Support is a nutritional supplement containing a combination of herbs, vitamins, and minerals that are thought to enhance prostate health. Two essential trace minerals for testosterone regulation, immune health, and prostate function. Long used in traditional African medicine and validated by modern research, pygeum supports bladder emptying, reduces prostate inflammation, and may enhance sexual function-making it a multi-benefit botanical for men's health. ProstaVive uses a purified, filler-free version that avoids the diluted extracts found in cheaper supplements.
