A 46 XY fetus is destined to become a male because the Y chromosome carries testicular determining gene which initiates transformation of the undifferentiated gonad into testes (Töhönen 2003). The testes subsequently produce both Mullerian Inhibiting Factor (to induce degeneration of the Mullerian system, the internal female ductal apparatus) and testosterone (to stimulate growth and development of the Wolffian system – epididymus, vas deferens, seminal vesicle and, after conversion to dihydrotestosterone (DHT) by the enzyme 5-α-reducase, the prostate gland). DHT is also the primary androgen to cause androgenization of the external genitalia.
Dr. Anthony's Notes: Creatine is damn effective. Period. It's research proven to benefit testosterone, energy levels, muscle preservation, and your brain function. Although creatine can be found naturally in a good high-protein diet, taking 5g daily is a great idea for most guys – especially those over 35. Remember to take your creatine AWAY from caffeine – the two substances inhibit each other's absorption. Verdict: this is one of the natural testosterone supplements that work. Best Food Sources: wild game (including venison, elk, buffalo, and bison), grass-fed beef, organic chicken, organic turkey, and wild-caught fish. How To Take Creatine Monohydrate: 5g daily away from caffeine.
Testosterone has two major effects on bones: (a) through conversion to estradiol by way of the enzyme, aromatase, testosterone inhibits osteoclastic activity and hence bone resorption; and (b) through conversion to DHT via 5-α-reductase, it stimulates osteoblastic activity and so enhances the laying down of bone (Tivesten et al 2004; Davey and Morris 2005). Hypogonadal men are at risk for the development of osteopenia or osteoporosis and hence for subsequent fracture (Fink et al 2006). About one-third of all osteoporotic hip fractures occur in men and the risk of any osteoporotic fracture in men over 50 is as high as 25 percent (Seeman 1997; Adler 2006). Although treatment with testosterone in hypogonadal men increases bone mineral density (Katznelson et al 1996), it has not yet been established that this results in a reduction in fracture rate.
A large number of trials have demonstrated a positive effect of testosterone treatment on bone mineral density (Katznelson et al 1996; Behre et al 1997; Leifke et al 1998; Snyder et al 2000; Zacharin et al 2003; Wang, Cunningham et al 2004; Aminorroaya et al 2005; Benito et al 2005) and bone architecture (Benito et al 2005). These effects are often more impressive in longer trials, which have shown that adequate replacement will lead to near normal bone density but that the full effects may take two years or more (Snyder et al 2000; Wang, Cunningham et al 2004; Aminorroaya et al 2005). Three randomized placebo-controlled trials of testosterone treatment in aging males have been conducted (Snyder et al 1999; Kenny et al 2001; Amory et al 2004). One of these studies concerned men with a mean age of 71 years with two serum testosterone levels less than 12.1nmol/l. After 36 months of intramuscular testosterone treatment or placebo, there were significant increases in vertebral and hip bone mineral density. In this study, there was also a significant decrease in the bone resorption marker urinary deoxypyridinoline with testosterone treatment (Amory et al 2004). The second study contained men with low bioavailable testosterone levels and an average age of 76 years. Testosterone treatment in the form of transdermal patches was given for 1 year. During this trial there was a significant preservation of hip bone mineral density with testosterone treatment but testosterone had no effect on bone mineral density at other sites including the vertebrae. There were no significant alterations in bone turnover markers during testosterone treatment (Kenny et al 2001). The remaining study contained men of average age 73 years. Men were eligible for the study if their serum total testosterone levels were less than 16.5 nmol/L, meaning that the study contained men who would usually be considered eugonadal. The beneficial effects of testosterone on bone density were confined to the men who had lower serum testosterone levels at baseline and were seen only in the vertebrae. There were no significant changes in bone turnover markers. Testosterone in the trial was given via scrotal patches for a 36 month duration (Snyder et al 1999). A recent meta-analysis of the effects on bone density of testosterone treatment in men included data from these studies and two other randomized controlled trials. The findings were that testosterone produces a significant increase of 2.7% in the bone mineral density at the lumber spine but no overall change at the hip (Isidori et al 2005). These results from randomized controlled trials in aging men show much smaller benefits of testosterone treatment on bone density than have been seen in other trials. This could be due to the trials including patients who are not hypogonadal and being too short to allow for the maximal effects of testosterone. The meta-analysis also assessed the data concerning changes of bone formation and resorption markers during testosterone treatment. There was a significant decrease in bone resorption markers but no change in markers of bone formation suggesting that reduction of bone resorption may be the primary mode of action of testosterone in improving bone density (Isidori et al 2005).
Conflicting results have been obtained concerning the importance of testosterone in maintaining cardiovascular health. Nevertheless, maintaining normal testosterone levels in elderly men has been shown to improve many parameters that are thought to reduce cardiovascular disease risk, such as increased lean body mass, decreased visceral fat mass, decreased total cholesterol, and glycemic control.
However, some of these signs and symptoms can be caused by factors other than low testosterone, including medication side effects, thyroid problems, depression and excessive alcohol use. There are also conditions, such as obstructive sleep apnea, that might affect testosterone levels. Once these conditions are identified and treated, testosterone typically will return to a normal level.
Testosterone insufficiency has been associated with HIV infection in men (Dobs et al 1988). Early reports suggested that testosterone therapy may have an ameliorating effect on both depression and decreased energy in HIV infected men, even if testosterone levels were not reduced (Rabkin et al 1999; Grinspoon et al 2000; Rabkin et al 2000). Both depression and fatigue, however, are common features of HIV-positive men and may be associated with factors other than reduced levels of testosterone. The disease itself may induce depression and fatigue may be a consequence of the disease, per se, or of some of the medications used to control HIV.
Saw palmetto: Uses, dosage, and side effects Saw palmetto is an extract from the berries of a type of palm tree. The berries have traditionally been used to ease urinary and reproductive problems. The extract is now used in herbal remedies to stabilize testosterone. Learn about its use, its effectiveness, the science behind the claims, and any side effects. Read now