Men who produce more testosterone are more likely to engage in extramarital sex. Testosterone levels do not rely on physical presence of a partner; testosterone levels of men engaging in same-city and long-distance relationships are similar. Physical presence may be required for women who are in relationships for the testosterone–partner interaction, where same-city partnered women have lower testosterone levels than long-distance partnered women.
The University of Connecticut recently published findings stating that those who supplemented with whey protein produced less cortisol, a stress hormone, than those who did not supplement. Cortisol lowers production of sex hormones and is also responsible for belly fat formation. Ricotta is an excellent source of natural whey protein and amino acids, both of which are essential to muscle growth and avoiding the spare tire.
Both testosterone and 5α-DHT are metabolized mainly in the liver. Approximately 50% of testosterone is metabolized via conjugation into testosterone glucuronide and to a lesser extent testosterone sulfate by glucuronosyltransferases and sulfotransferases, respectively. An additional 40% of testosterone is metabolized in equal proportions into the 17-ketosteroids androsterone and etiocholanolone via the combined actions of 5α- and 5β-reductases, 3α-hydroxysteroid dehydrogenase, and 17β-HSD, in that order. Androsterone and etiocholanolone are then glucuronidated and to a lesser extent sulfated similarly to testosterone. The conjugates of testosterone and its hepatic metabolites are released from the liver into circulation and excreted in the urine and bile. Only a small fraction (2%) of testosterone is excreted unchanged in the urine.
Studies have demonstrated reduced testosterone levels in men with heart failure as well as other endocrine changes (Tappler and Katz 1979; Kontoleon et al 2003). Treatment of cardiac failure with chronic mechanical circulatory support normalizes many of these changes, including testosterone levels (Noirhomme et al 1999). More recently, two double-blind randomized controlled trials of testosterone treatment for men with low or low-normal serum testosterone levels and heart failure have shown improvements in exercise capacity and symptoms (Pugh et al 2004; Malkin et al 2006). The mechanism of these benefits is currently unclear, although a study of the acute effects of buccal testosterone given to men with chronic cardiac failure under invasive monitoring showed that testosterone increased cardiac index and reduced systemic vascular resistance (Pugh et al 2003). Testosterone may prove useful in the management of cardiac failure but further research is needed.
Cognitive abilities differ between males and females and these differences are present from childhood. In broad terms, girls have stronger verbal skills than boys who tend to have stronger skills related to spatial ability (Linn and Petersen 1985). It is thought that the actions of sex hormones have a role in these differences. Reviewing different cognitive strengths of male versus female humans is not within the scope of this article but the idea that cognition could be altered by testosterone deserves attention.
Zinc is involved in virtually every aspect of male reproduction, including testosterone metabolism. Several studies support the use of zinc for treating low sperm counts, especially when accompanied by low testosterone levels. In these studies, zinc has shown an ability to raise both sperm counts and testosterone levels. Many men may be suffering from low testosterone simply because of a zinc deficiency. Taking 30–45 mg of zinc per day is recommended; balance with 2–3 mg of copper for best results.
Intracoronary artery infusion of testosterone causes significant coronary artery dilatation and not constriction as previously thought (Webb et al 1999). When degree of coronary obstruction is assessed by angiography, there is a direct relationship between degree of coronary artery narrowing and reduced testosterone levels (Phillips et al 1994). Men with low testosterone levels have been observed to have: premature atherosclerosis, increased visceral adipose tissue, hyperinsulinemia, and other risk factors for myocardial infarction (Phillips 2005). Insulin resistance has been shown to be associated with a decrease in Leydig cell secretion of testosterone (Pitteloud et al 2005). Muller and colleagues suggest that low endogenous total testosterone and SHBG levels increase the risk of metabolic syndrome in aging and aged men. They demonstrated that low levels of testosterone are related to lower insulin sensitivity and higher fasting insulin levels (Muller et al 2005). These authors speculate that testosterone might play a protective role in the development of metabolic syndrome, insulin resistance, diabetes mellitus and cardiovascular disease in aging men.
This summary is intended for general informational purposes only, and should not be interpreted as specific medical advice. The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of purity, strength, or safety of the products. As a result, effects may vary. You should read product labels. In addition, if you are taking medications, herbs, or other supplements you should consult with a qualified healthcare provider before taking a supplement as supplements may interact with other medications, herbs, and nutritional products. If you have a medical condition, including if you are pregnant or nursing, you should speak to your physician before taking a supplement. Consult a healthcare provider if you experience side effects.
Pellets. Your doctor will place the testosterone pellets under the skin of your upper hip or buttocks. Your doctor will give a shot of local anesthesia to numb your skin, then make a small cut and place the pellets inside the fatty tissues underneath your skin. This medication dissolves slowly and is released over about 3-6 months, depending on the number of pellets.
"A lot of the symptoms are mirrored by other medical problems," Hedges says. "And for a long time, we were not attributing them to low testosterone, but to diabetes, depression, high blood pressure, and coronary artery disease. But awareness and appreciation of low testosterone has risen. We recognize now that low testosterone may be at the root of problems."