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]
Carbs play a big part in determining your Testosterone levels. Let's start with what to avoid. First, research shows that a large serving of sugar (75g of glucose), decreased Testosterone levels by as much as 25%! (25 & 26). I know this is a pretty extreme dosage, but you may want to avoid massive servings of sugar! Also, men who have Metabolic syndrome have lower Testosterone levels (27). Metabolic syndrome is often brought about by chronic high blood sugar which leads to insulin resistance.
A: According to the NIH, normal values for testosterone levels in men can range from 300 to 1,200ng/dL. There can be many different causes of low testosterone including age, diseases, accidents, and medications. Symptoms of low testosterone may include: loss of sex drive, erectile dysfunction, depressed mood, and difficulty concentrating. Low testosterone levels may also bring around body changes including: hair loss, decrease in blood cells possibly leading to anemia, fragile bones, and a decrease in muscle mass. There are different testosterone replacement therapies including patches, such as Androderm; gels, such as Androgel and Testim; and injections, such as testosterone cypionate. Only your health care provider can decide if and what kind of testosterone replacement therapy is appropriate for you. Testosterone replacement therapy is not right for everyone. Patient with certain prostate issues or breast cancer should not take testosterone. For more specific information, consult with your doctor for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD
In many of the studies we found, those who saw the most improvement in health, testosterone, or muscle gain were those with existing nutrient or vitamin deficiencies. This means that some gains may be due more to dietary changes and generally restoring nutrient and vitamin levels than any one magic ingredient, but also that making sure your diet includes healthy amounts of nutrients should be your first step.

Among the changes which occur with aging are those that affect several aspects of the endocrine system which reduces its secretions to varying degrees in different individuals. These reductions in secretions are identified by a poor but widely recognized appellation, the “pauses”: menopause (decreased ovarian function), adrenopause (decreased adrenal function, especially with regard to dehydroepiandrosterone secretion), somatopause (decreased growth hormone production), andropause (decreased hypothalamic-pituitary testicular function with diminished testosterone availability and impaired spermatogenesis) (Lamberts 1997).


If in a 46 XY individual testosterone is either not produced in adequate concentrations as in gonadal dysgenesis (MacLaughlin and Donahue 2004), or in the absence of the enzyme 17 alpha-hydroxylase so that testosterone is not produced (Ergun-Longmire et al 2006), or testosterone androgen receptors are absent as in the androgen insensitivity syndrome (Hughes and Deeb 2006), phenotypic females will result.
Many clinical studies have looked at the effect of testosterone treatment on body composition in hypogonadal men or men with borderline low testosterone levels. Some of these studies specifically examine these changes in older men (Tenover 1992; Morley et al 1993; Urban et al 1995; Sih et al 1997; Snyder et al 1999; Kenny et al 2001; Ferrando et al 2002; Steidle et al 2003; Page et al 2005). The data from studies, on patients from all age groups, are consistent in showing an increase in fat free mass and decrease in fat mass or visceral adiposity with testosterone treatment. A recent meta-analysis of 16 randomized controlled trials of testosterone treatment effects on body composition confirms this pattern (Isidori et al 2005). There have been less consistent results with regard to the effects of testosterone treatment of muscle strength. Some studies have shown an increase in muscle strength (Ferrando et al 2002; Page et al 2005) with testosterone whilst others have not (Snyder et al 1999). Within the same trial some muscle group strengths may improve whilst others do not (Ly et al 2001). It is likely that the differences are partly due to the methodological variations in assessing strength, but it also possible that testosterone has different effects on the various muscle groups. The meta-analysis found trends toward significant improvements in dominant knee and hand grip strength only (Isidori et al 2005).
Inaccurate or misinterpreted test results can either falsely diagnose or miss a case of testosterone deficiency. Your testosterone level should be measured between 7 am and 10 am, when it's at its peak. Confirm a low reading with a second test on a different day. It may require multiple measurements and careful interpretation to establish bioavailable testosterone, or the amount of the hormone that is able to have effects on the body. Consider getting a second opinion from an endocrinologist.
Low testosterone levels may contribute to decreased sex drive, erectile dysfunction, fragile bones, and other health issues. Having low testosterone levels may also indicate an underlying medical condition. See your doctor if you suspect you have low testosterone. A simple blood test is all it takes to check if your testosterone falls within the normal range.
Testosterone was first used as a clinical drug as early as 1937, but with little understanding of its mechanisms. The hormone is now widely prescribed to men whose bodies naturally produce low levels. But the levels at which testosterone deficiency become medically relevant still aren’t well understood. Normal testosterone production varies widely in men, so it’s difficult to know what levels have medical significance. The hormone’s mechanisms of action are also unclear.
Natural remedies for treating erectile dysfunction Erectile dysfunction has many causes, can affect any male, and is often distressing? Some people advocate several different natural remedies, mostly herbs and other plants. Here, we look at their merits and side effects, plus lifestyle changes, and alternative therapies that may bring relief for erectile dysfunction. Read now
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