Although testosterone is principally a male hormone, it is found at significant levels in the female. There has been less research done on the effects of testosterone in women, but this is presently being corrected.

Meanwhile, it is known that testosterone levels tend to decrease with age in women, as is the case for the other hormones as well. Which suggests that if a woman seeks to replace her declining female hormones, she would be well advised to undertake testosterone replacement also.

It is a near certainty that testosterone, along with the female hormones, plays a significant role in the female libido. In a woman's monthly cycle, her testosterone levels, as well as her progesterone levels, are at a high point after ovulation. Which is when many women experience their strongest sexual desire.

Another indication of testosterone's link with the female hormones is seen in another area, bone formation. We saw that when progesterone was included with estrogen in replacement therapy, not only was osteoporosis retarded, but it was reversed. So too is the case when testosterone is added to estrogen in those circumstances.

As further research is completed there will, no doubt, be much more information forthcoming concerning the function of testosterone in both men and women.