The brain is also affected by this sexual differentiation; the enzyme aromatase converts testosterone into estradiol that is responsible for masculinization of the brain in male mice. In humans, masculinization of the fetal brain appears, by observation of gender preference in patients with congenital diseases of androgen formation or androgen receptor function, to be associated with functional androgen receptors.
There have been a number of smaller studies on men receiving testosterone-replacement therapy, and if you look at the results cumulatively, the rate of prostate cancer in these men was about 1% per year. If you look at men who show up for prostate cancer screening, same sort of age population, the rate tends to be about the same. You have to be cautious in comparing studies and combining the results, but there’s no signal in these results that testosterone-replacement therapy creates an unexpectedly high rate of prostate cancer.
Currently available testosterone preparations in common use include intramuscular injections, subcutaneous pellets, buccal tablets, transdermal gels and patches (see Table 2). Oral testosterone is not widely used. Unmodified testosterone taken orally is largely subject to first-pass metabolism by the liver. Oral doses 100 fold greater than physiological testosterone production can be given to achieve adequate serum levels. Methyl testosterone esters have been associated with hepatotoxicity. There has been some use of testosterone undecanoate, which is an esterified derivative of testosterone that is absorbed via the lymphatic system and bypasses the liver. Unfortunately, it produces unpredictable testosterone levels and increases testosterone levels for only a short period after each oral dose (Schurmeyer et al 1983).
If you're completely inactive, or if you're completely burned out from overly intense training, neither one is going to help your T-levels. And when it comes to nutrition, eating enough—and getting adequate dietary fats—are both essential for healthy testosterone levels, and for general health. In "All About Testosterone," Chris Lockwood, Ph.D., notes that extreme low-calorie dieting and fasting will hinder testosterone levels from staying at their peak, along with better-known villains like chronic stress.
One preliminary study by researchers from Tikrit University showed high statistically significant increase of serum hormones (p< 0.01) in infertile men . After 30 week treatment serum testosterone has increased by 17,7%, serum luteinizing hormone by 43,2% and serum follicle-stimulating hormone by 17,6%; dosage of ginger used was not disclosed . It is suggested that improved testosterone production is because ginger was shown to be effective in decreasing SDF (sperm DNA Fragmentation) in infertile men . SDF is negatively correlated with testosterone levels .
In effect, older men with low testosterone and age-associated memory impairment (AAMI) did not benefit from short-term treatment with testosterone, as reported in the current issue of the Journal of the American Medical Association (JAMA),1 by Susan M. Resnick, PhD, a senior investigator at the National Institute on Aging in Baltimore, Maryland, and colleagues.
Vitamin D3. Vitamin D3 actually isn’t a vitamin, it’s a hormone — a really important hormone that provides a whole host of health benefits. Our bodies can naturally make vitamin D from the sun, but recent studies have shown that many Westerners are vitamin D3 deprived because we’re spending less and less time outdoors. When we do decide to venture outside, we slather our bodies with sunscreen, which prevents the sun reaching our skin to kick-off vitamin D3 production. If you’re not getting enough sun, you may have a vitamin D3 deficiency, which may contribute to low T levels. If you think you need more vitamin D3, supplement it with a pill. Studies have shown that men who take this supplement see a boost in their testosterone levels. Because I have a darker complexion — which makes me prone to Vitamin D3 deficiency — I took 4,000 IU of vitamin D3 in the morning.
Longjack, also known as Tongkat ali and pasak bumi, is a shrub hailing from Southeast Asia purporting to improve libido. It’s gaining traction in the scientific community for potentially increasing testosterone levels, and researchers at South Africa’s University of the Western Cape found that longjack improved testosterone levels and muscular strength in physically active seniors (a population with typically low testosterone).
Proprietary blends are a growing problem in the supplement industry. This is where mix many ingredients together and list it on the label as a blend. The problem with this is you have no idea how much of each of those ingredients you are getting. Complete transparency is best so the customer knows what they are getting and it also helps limit side-effects.
The science backs up the soldier’s self discovery, in fact, exposure to radiation (whether it’s from an army radar or the cell phone in your pocket, or the wifi router in your house) has been shown to lower sperm quality, fertility and testosterone. This is true not only for military personnel (88, 89,90) but all males living in a modern world (91).