Testosterone for Women? Yes.
Chew on this: Testosterone has long been characterized as the "male hormone" when, in fact, it's also the most abundant active hormone in women. Sure, men have higher circulating testosterone levels than women, but regardless, testosterone, not estrogen, is the predominant sex steroid in women throughout their entire lifespan, or so say scientists Rebecca Glaser and Constantine Dimitrakakis.
The two scientists, writing in "Maturitas," urge us to "look at how women's estrogen levels are measured – in mere picograms per milliliter, while their T levels are measured in nanograms per deciliter, a 10-fold higher unit of measurement."
Beyond estrogen, there are even higher, exponentially higher, amounts of pro-androgens circulating through their bodies, players like dehydroepiandrosterone sulfate (DHEA), dehydroepiandrosterone (DHEA), and androstenedione, each of which supply significant amounts of additional T.
Heck, even the gene for the androgen receptor that testosterone and other sex hormones latch onto is located on the X chromosome and not the Y, or male chromosome. Glaser and Dimitrakakis lamented the medical establishment's myopic stance by writing, "Despite any clear rationale, estrogen was assumed to be the hormone of 'hormone replacement therapy' in women."
They point out that this assumption occurred despite testosterone – as early as 1937 – being the treatment of choice when it came to treating female menopause.
So why is it that testosterone has been largely dismissed as a viable treatment for women facing pre- and postmenopause? Even me, a self-taught student of endocrinology, has long wondered how the hell the medical establishment freely offers women estrogen and progesterone replacement but wavers or dithers on doling out testosterone. How can you expect good results by only shoring up two of the three primary legs that support female hormonal health? It's nuts.
However, when you start to look at all the myths associated with testosterone – some of which have also hindered the acceptance of male testosterone replacement – you begin to understand WTF has been going on.
While some of the decidedly masculine circa 1970 female Olympic athletes from East Germany and the U.S.S.R. played a part in the origin of this myth, it was competitive female bodybuilding that did the most damage.
I personally know women that once had voices like sweet, sweet nightingales who later, after taking stupid amounts of anabolic/androgenic steroids (which are all synthetic derivatives of testosterone), ended up sounding like the guys who do voiceovers for Coors Beer and Ford trucks; women who had to start shaving their faces every day except maybe for weekends when they didn't have to go to work and could just putter around the garage.
So yeah, no wonder the medical establishment and their patients fear testosterone, but what they need to know is that all that scary stuff is dose dependent and that the doses used for T replacement in women actually "stimulate femininity" by increasing fertility and promoting ovulation. T was even used safely in the past to treat the nausea that often accompanies early pregnancy.
Still, side effects do sometimes occur, but Glaser and Dimitrakakis write that "true masculinization is not possible (with normal doses)." Even so, the benefits are often so great that some women often choose to treat the side effects rather than lower the dosage.
The authors also admit that, yes, pharmacologic and supra-pharmacologic doses of T are used to transform female-to-male transgender patients and that it may result in increased facial hair growth, hirsutism in general, and slight enlargement of the clitoris, but these effects are often largely reversible by simply lowering the dose.
Even so, an enlarged clitoris is not a medical problem, only a superficial cosmetic one that might invite embarrassment even though, in many cases, the additional length or girth can enhance sexual pleasure.
So no, when used in normal replacement doses, testosterone doesn't masculinize women; it largely does the opposite.
Sure, testosterone replacement therapy (TRT) in women often cranks up a once-flagging libido, but women have androgen receptors (AR) all over the place and not just in their brain and their reproductive parts. They're found in the heart, breast, blood vessels, lung, spinal cord, bladder, peripheral nerves, bone, bone marrow, synovium (soft tissue that lines joint capsules), adipose tissue, muscle, and of course, the uterus, ovaries, and vaginal tissues.
Just as in men, the testosterone levels of women start to decline with age, bringing about anxiety, irritability, depression, physical fatigue, bone loss, muscle loss, insomnia, changes in cognition, memory loss, breast pain, urinary complaints, and yes, sexual dysfunction as well as sexual indifference.
Clearly, testosterone plays a big part in women's health that goes way beyond just feeding the urge to put on some good "doing it" music when their partner comes home.
You can see how this myth started: Men have more testosterone than women, and men have more heart attacks than women. That's an example of what's called a causal fallacy.
It's like believing that every time you turn on "The Young and the Restless," it causes the neighbor's dog to start barking. It's more likely that the mailman comes around the same time that the soap opera starts rather than the dog having some preternatural connection to Devon, Abby, Chance, Lauren, Victoria, or Billy.
Back to men and their hearts: If T is involved in their heart attacks, it's more likely to do with low T levels as that condition has been associated with an increased risk of disease and mortality from all causes. Quite the contrary to what is commonly believed, there's overwhelming evidence that T is cardioprotective, helping men and women with their glucose metabolism and lipid profiles (two factors that play a role in heart disease).
Testosterone also expands blood vessels, making it easier for the blood to surge past any plaque or partial blockages. It also has immune-modulating effects that can inhibit the formation of those same blockages.
This isn't just conjecture, either. Clinical studies have shown T to improve the functional capacity, insulin resistance, and muscle strength in men and women with congestive heart failure.
Of course, a certain amount of T does aromatize (chemically convert) to estrogen, and this excess estrogen can cause adverse side effects in both heart patients and healthy individuals. These side effects would include swelling, anxiety, and weight gain. Furthermore, other medications often used to treat heart disease can increase aromatization, indirectly leading to side effects from T therapy.
The info that you can pocket, though, is that T is largely cardioprotective, and having normal or adequate levels can decrease the risk of cardiovascular disease.
T doesn't cause liver damage, but it's easy to see from where this belief came. Bodybuilders, pro athletes, and pathologically vain people often take staggering doses of oral, synthetic versions of testosterone (steroids), which are then processed by the liver and, over the long run, can cause a significant amount of damage that's probably not much different from taking a slab of liver and tossing it into a frying pan.
T itself, though, isn't taken orally; it's either injected, implanted (as a pellet), or absorbed through the skin as a cream or gel. Each of these methods allows testosterone to bypass the liver. The organ avoids the "fight" and hence walks away unscathed.
As Glaser and Dimitrakakis point out, "hair loss is a complicated, multifactorial, genetically determined process that is poorly understood." There is, however, little or no evidence that T or T therapy is a cause of hair loss in women. It's true that women with polycystic ovary disease and the accompanying insulin resistance have higher T levels and experience hair loss, but that, again, doesn't prove causation, and besides, hair loss is common in women and men with insulin resistance.
What happens is that insulin resistance (and obesity) increases levels of the 5-alpha-reductase enzyme, which can result in some testosterone being "reduced" to dihydrotestosterone, or DHT, which is the androgen involved in balding.
However, this isn't the case in healthy women, many (about a third) of whom start to experience hair loss with aging, which coincides with a decline in T levels. Remarkably, and contrary to what most people believe, including doctors, two-thirds of women who undergo TRT start to experience hair regrowth. And many of those who don't are more likely to be experiencing some contributing medical problem, like having hypo or hyperparathyroidism, being deficient in iron, or being obese.
As evidence of T's innocence in causing hair loss in women, none of 285 patients treated for up to 56 months with T therapy complained of hair loss.
Despite the propensity of men who commit acts of aggression to blame it on "testosterone aggression" or "roid rage" instead of their inherent emotional instability, this type of thing is either rare or nonexistent with the TRT, especially in women – the doses are just too small.
Besides, there's significant evidence "in a wide variety of species" that it's estrogen, not testosterone, that plays a major role in aggression. Of course, some testosterone does aromatize (enzymatically convert to estrogen) in both women and men, but again, the amount of estrogen resulting from conventional doses of TRT wouldn't lead to any noticeable changes in female Hulk-nicity, i.e., the "you wouldn't like me when I'm angry" factor.
Quite the contrary, studies have found that subcutaneous (under the skin) implantation of T pellets has led to decreased aggression, irritability, or anxiety in 90% of patients treated for T deficiency.
Okay, it's long been known that breast cancer is an estrogen-sensitive cancer, but clinical trials have found that T has a beneficial effect on breast tissue in that it decreases breast cancer cell proliferation and prevents breast cancer-cell stimulation.
It appears that the ratio of T to estrogen (E2), or the balance of these two hormones, deserves some of the credit in making T breast-protective. Furthermore, once you activate the androgen receptor (to which estrogen and testosterone latch onto), it "exerts a pro-apoptopic (causes cancer cells to die), anti-estrogenic, growth-inhibiting effect in normal and cancerous breast tissues."
I'd be remiss, though, in failing to mention that – as explained earlier – some testosterone can be aromatized into estrogen, which risks upsetting the hormonal apple cart if not monitored. Regardless, it still appears that T lowers the risk of breast cancer in women who have been treated with estrogen therapy.
T replacement for women isn't some new fangled thing. England and Australia have been treating women with T for almost 70 years. Testosterone implants have been safely used in women since 1938. There's long-term data on the safety and tolerability of T in women using doses up to 225 mg., which is a really high amount, especially for women.
All that being said, aromatase activity (which converts T into estrogen) increases with age, obesity, alcohol intake, breast cancer, insulin resistance, medications, recreational drugs, a sedentary lifestyle, and the unfettered intake of heavily processed foods. Combine that fact with the potential for even more production of estrogen through T replacement, and the risk of a hormonal imbalance increases.
That makes it important for physicians to monitor aromatase levels in women who are being treated with T so that the T to E ratio is maintained within safe boundaries and that patients' health is assured.
Unfortunately, testosterone is still regarded as a schedule 3 drug, which means the DEA, regardless of any exonerating evidence, thinks it has the potential to cause adverse effects. To be fair, it can when not administered or monitored properly, but so can cherry-flavored aspirin, Flintstones vitamins, or Tums.
While some modern-day doctors are certainly prescribing testosterone to their female patients, its schedule 3 classification likely makes other physicians understandably hinky about doing so.
The main barrier to its more widespread use, though, at least in the United States, is the mythology that's grown around the use of testosterone. Hopefully, this article and others like it can help chip away at that mythology.
- Rebecca Glaser et al. Testosterone Therapy in Women: Myths and Misconceptions. Maturitas. 2013;74:230-234.