As blood levels of testosterone increase, this feeds back to suppress the production of gonadotrophin-releasing hormone from the hypothalamus which, in turn, suppresses production of luteinising hormone by the pituitary gland. Levels of testosterone begin to fall as a result, so negative feedback decreases and the hypothalamus resumes secretion of gonadotrophin-releasing hormone. 
In addition to its role as a natural hormone, testosterone is used as a medication, for instance in the treatment of low testosterone levels in men and breast cancer in women.[10] Since testosterone levels decrease as men age, testosterone is sometimes used in older men to counteract this deficiency. It is also used illicitly to enhance physique and performance, for instance in athletes.

Dr. Adriane Fugh-Berman, associate professor of pharmacology and director of the industry watchdog group at Georgetown University School of Medicine, calls this kind of direct-to-consumer pharmaceutical advertising "evil." She likened the efforts to sell TRT to earlier campaigns to push hormone replacement therapy for post-menopausal women. "They stole the playbook," she said. "This hormone is being thrown around like sugar water."
Alcohol should be avoided when trying to increase testosterone levels. Healthy normal men, consuming reasonable amounts of alcoholic drink, experience a 20% drop in their serum levels of testosterone. In chronic alcoholics with extensive liver damage those levels can be reduced by as much as 50% and they can become feminized (loose facial and pubic hair, become impotent, and fat deposits behind the nipples that give the appearance of breasts).
We required all of our testosterone boosters to have magnesium, but gave preference to magnesium aspartate, citrate, lactate, and chloride. These forms have been found to be more easily absorbed than magnesium oxide and sulfate. (On the other hand, it didn’t count if the supplement had magnesium stearate, which is used to make pills not stick together.)
In addition to conjugation and the 17-ketosteroid pathway, testosterone can also be hydroxylated and oxidized in the liver by cytochrome P450 enzymes, including CYP3A4, CYP3A5, CYP2C9, CYP2C19, and CYP2D6.[155] 6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations.[155] The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism.[155] In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites.[155][156] Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.[155]
As you cut these dietary troublemakers from your meals, you need to replace them with healthy substitutes like vegetables and healthy fats (including natural saturated fats!). Your body prefers the carbohydrates in micronutrient-dense vegetables rather than grains and sugars because it slows the conversion to simple sugars like glucose, and decreases your insulin level. When you cut grains and sugar from your meals, you typically will need to radically increase the amount of vegetables you eat, as well as make sure you are also consuming protein and healthy fats regularly.
Vitamn D is a fat-soluble vitamin naturally found in a variety of foods, but it is also produced in your skin. Exposure to the sun’s ultraviolet rays causes your skin to synthesize vitamin D. This vitamin is best known for its interactions with calcium. Vitamin D promotes proper absorption of calcium in your stomach and intestines and regulates calcium and phosphate levels to ensure that your bones undergo normal mineralization. Vitamin D deficiencies have been linked to thin, brittle or misshapen bones as well as rickets in children. Having enough vitamin D and calcium protects adults from osteoporosis.
Sharma, R., Oni, O. A., Gupta, K., Chen, G., Sharma, M., Dawn, B., … & Barua, R. S. (2015, August 6). Normalization of testosterone level is associated with reduced incidence of myocardial infarction. European Heart Journal, 36(40), 2706-2715. Retrieved from