The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[183] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887–1976) and A. Wettstein, published their synthesis of testosterone.[184] These independent partial syntheses of testosterone from a cholesterol base earned both Butenandt and Ruzicka the joint 1939 Nobel Prize in Chemistry.[182][185] Testosterone was identified as 17β-hydroxyandrost-4-en-3-one (C19H28O2), a solid polycyclic alcohol with a hydroxyl group at the 17th carbon atom. This also made it obvious that additional modifications on the synthesized testosterone could be made, i.e., esterification and alkylation.
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).
Tailor the above recommendations to your personal needs and lifestyle. If you’re a vegetarian drop the bacon and steak, but keep the whey protein and eggs. If you have an injury that prevents you from heavy weightlifting, move as much as you can in the way that you can. There are no studies out there which can tell you exactly what will happen if you do X and Y, but not Z. And I certainly can’t tell you either. Don’t be afraid of self-education – that’s how I learned all this – and embrace the idea of conducting your own experiment and being your own test subject. Incorporate as many of the recommendations above as you’re comfortable with, consult your doctor, and track your results.
Testosterone levels generally peak during adolescence and early adulthood. As you get older, your testosterone level gradually declines — typically about 1 percent a year after age 30 or 40. It is important to determine in older men if a low testosterone level is simply due to the decline of normal aging or if it is due to a disease (hypogonadism).