6., 7. JK, Udani, George AA, Musthapa M, Pakdaman MN, and Abas A. "Effects of a Proprietary Freeze-Dried Water Extract of Eurycoma Longifolia (Physta) and Polygonum minus on Sexual Performance and Well-Being in Men: A Randomized, Double-Blind, Placebo-Controlled Study." National Center for Biotechnology Information. U.S. National Library of Medicine, 12 Jan. 2014.
A meta-analysis of nine randomized controlled trials [31] evaluated effects of ginger on net changes in blood glucose and lipid concentrations (total cholesterol, triglyceride, low-density lipoprotein cholesterol, high density lipoprotein cholesterol).  In a total of 609 adults with T2DM or hyperlipidemia, ginger supplementation led to significant reductions in plasma levels of total cholesterol, triglycerides, and blood glucose, but non-significant reduction in LDL-c levels.
Testosterone levels generally peak during adolescence and early adulthood. As you get older, your testosterone level gradually declines — typically about 1 percent a year after age 30 or 40. It is important to determine in older men if a low testosterone level is simply due to the decline of normal aging or if it is due to a disease (hypogonadism).