K... this testosterone thing...

Testosterone is one of the androgenic hormones responsible for anabolism in the body (Kraemer & Ratamess). It is testosterone that is responsible for masculine traits (i.e. excess hair (especially facial), deepening of voice, increase in muscle mass). Both males and females produce testosterone, as it is necessary for hormonal balance and body function (Marieb, 2004). However, males have much HIGHER levels of testosterone than females, with the ‘normal’ range of total testosterone (in the bloodstream) being 0.95-4.3 pg/dl, compared to the 0.7-3.6 pg/dl of females. However, it is not so much the total amount of testosterone that an individual has that determines their potential/ability for muscle growth, since most of the testosterone in the body is bound to either sex hormone binding globulin (SHBG) or other non-specific proteins such as albumin (Wheeler, 1995), but their levels of FREE testosterone (i.e. the amount of testosterone that is NOT bound in the body). In males 0.3-5% (with an average of 2%) of their total testosterone if free, with their free testosterone normal values being 270-1100 ng/dl, compared to only 6-86 ng/dl of free testosterone available to females.

Just as many people have the misconception that weight training or lifting heavy weights will suddenly cause a woman to exhibit masculine traits, so many people also hold the inaccurate belief that non-hormonal anabolic products – like testosterone boosters – should not be used by women, for fear that they will cause androgenic side effects. However, increasing a woman’s testosterone levels through using natural and herbal supplementation is unlikely to cause such effects, as women have much lower free testosterone levels than men (6-86 ng/dl, compared to the 270-1100 ng/dl of bioavailable testosterone in men), and it is free testosterone that determines such effects; and even if a woman’s total testosterone is increased, it is not significant enough to change her hormonal balance to be comparative to that of a man physiologically.