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.
The participants were seen every 4 weeks. Blood was taken to measure hormone levels, and questionnaires were given to assess physical function, health status, vitality, and sexual function. Body fat and muscle measurements were also taken at the beginning and end of the 16 weeks. The study was funded in part by NIH’s National Institute on Aging (NIA) and National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Results appeared in the September 12, 2013, issue of the New England Journal of Medicine.
The normal development of the prostate gland is dependent on the action of testosterone via the androgen receptor, and abnormal biosynthesis of the hormone or inactivating mutations of the androgen receptor are associated with a rudimentary prostate gland. Testosterone also requires conversion to dihydrotestosterone in the prostate gland for full activity. In view of this link between testosterone and prostate development, it is important to consider the impact that testosterone replacement may have on the prevalence and morbidity associated with benign prostatic hypertrophy (BPH) and prostate cancer, which are the common conditions related to pathological growth of the prostate gland.
‘Testosterone boosting’ products - found online, or in health food or body-building shops, these products claim to boost testosterone levels if you buy them. The majority of these products will not have the effect you want and are not worth spending money on. Any of these products that do have a real effect may have a form of prescription medication in which is both dangerous and illegal.
"I went from 230 pounds down to 192. When my son got married, I went for the suit fitting, and I was a size 48. When I went back to do the final fitting, I was a 44! I want to keep getting it for the weight loss; I lost 4 inches around my belly, and I want to get rid of the rest of the weight around my belly. I’m 57, and my wife says I look like I’m back in my 30s. I have more energy for sure, and I’m going to participate in one of those Savage races where they have the obstacle courses with one of our kids."
Caffeine. Use caffeine moderately. Too much of the jittery juice increases cortisol, which decreases testosterone. Moreover, consuming caffeine late in the day hurts sleep, which lowers testosterone production. But one recent study indicates that caffeine consumed before working out may boost testosterone levels and help you exercise more efficiently. During my experiment I popped a piece of caffeinated gum five minutes before my workouts. Each piece had 100 mg of caffeine, about the same amount in a cup of coffee. That was usually it for my caffeine intake that day.