Part 7: Free Testosterone

I just returned from a conference of The International Society for the Study of Women's Sexual Health (ISSWSH). One of the topics that will received lots of "air time" is testosterone levels and supplementation in women. And, so it should.

It's been pretty amazing to me that testosterone is so misunderstood by consumers and by medical professionals. I wish that I had a dollar for every time I've heard a female client who had inquired about testosterone tell me that her medical care professional had commented, "Do you want to grow a beard?" or "Your voice will deepen" or "You'll get acne."

The masculinization effects of testosterone supplementation are grossly overestimated when it is properly used (which is about one-tenth of a male dose). I have seen many women successfully supplement their testosterone levels and restore their sexual interest. But to do it well, it's important to get the right measurements.

Total testosterone (the blood test more commonly authorized) tells how much testosterone is in the bloodstream all together. Some of that testosterone is bound to molecules such as SHBG (sex hormone binding globuline). When it's bound, it does not create a physiologic sense of sexual desire. So, we want to know about the free testosterone instead.

Free testosterone is just that -- free. It is not bound and therefore does provide some of the momentum for sexual desire based on hormones. So, knowing the free testosterone can lead the way to assessing the possible benefit of supplementing with testosterone. Merely giving a woman some testosterone and seeing how she does without blood tests is not good science.

But there's a problem with measuring free testosterone. Most labs do not use equilibrium dialysis, the "gold standard" method for measuring it. So, there's another way to get a very accurate assessment of a woman's free testosterone.

Here it is. Do two blood tests: the total testosterone and the SHBG (sex hormone binding globulin). Then run those numbers through the free testosterone calculator here. The normal calculated free testosterone is 0.4 - 0.8 ng/dl (or 40 - 80 pg/dl). If a woman is low, she can consider supplementing.

Transdermal methods currently are deemed the best method for supplementing. So, gels can be prescribed at a one-tenth male dose as a good starting point. They can be applied to the hips and calves "Macarena style."

It is likely that once the trepidation about masculinizing women subsides, the FDA will allow the testosterone patch to receive approval. In May 2006, the European Medicines Agency, a European organization that is their equivalent of our FDA, just approved the testosterone patch made by Proctor and Gamble (the same one that had been heading to the U.S. market last year before a case of the nerves set in).

It's important to remember that a testosterone gel or patch will not solve all aspects of a woman's lack of sexual interest -- far from it! (That's why there were nine other reasons on this list!) But, a woman who once had adequately high testosterone and then experiences a change (for reasons that we are still exploring), may very well find testosterone supplementation to be exactly what she needs. And, women who may have had low free testosterone throughout their lives, might get a chance to learn what all the fuss is about.

Related Topics: Menopause and Perimenopause: Medications, Less Sexual Desire After the Pill?

Technorati Tags: sexuality, women's health, testosterone