Testosterone for Women

A women in her late twenties, came to see me complaining about her difficulty in losing weight. After taking a medical history, it was very difficult to tell what the basis of her problem was. She was working out daily, with a balance of aerobic exercise and weight training under the guidance of a qualified personal trainer. Her diet was a basic low carbohydrate/ high protein diet. Even more perplexing, she had been taking a caffeine/ephedrine thermogenic stack and had previously experimented with some diet drugs as well. Something was obviously wrong. I did blood tests to check all of her hormone levels. When the results came back, all of her hormones were in the normal range except for, you guessed it, testosterone! She had very low free testosterone level. It was equal to that seen in a postmenopausal women. This was an obvious source of her fat loss problem .

While the role of testosterone in maintaining muscle mass and losing body fat may be obvious to bodybuilders and athletes, it is a basic hormonal fact that is often absent in the medical community. It is known that many women begin to gain fat rapidly about ten to fifteen years before the menopause and also after. The connection between low to absent testosterone production and the deterioration of a healthy body composition is rarely made. Most women are often only given estrogens and progestins as hormone replacement therapy, but not testosterone. I have found in my medical practice that giving women estrogen and progesterone and not testosterone makes it almost impossible for them to lose weight/fat. With the scourge of increasing obesity in the USA, one would expect the medical community to pay closer attention to these issues. Yet the connection between sex hormones, and body composition is highly controversial.

Why is there such a controversy? Why is a hormone commonly used by farmers to fatten up livestock given to postmenopausal women at risk for obesity? Many doctors point to a recent study showing that when postmenopausal women given estrogen actually gained less weight than those not given estrogen. In this study 875 women were either put on .625 mg of oral estrogen a day or a placebo for three years. So does this mean that estrogen is actually a good fat-loss agent? Hardly! In this study, in spite of the publicity it was given, the authors note that when you control for lifestyle factors such as physical activity the effects of estrogen replacement therapy were insignificant.

From my clinical experience I have found that on the average when a young woman goes on birth control pills a 3-5 pound gain in fat mass can be expected, and at menopause with oral estrogens 4-8 pounds of fat mass gain can be anticipated - especially when oral estrogens are used. A recent controlled study showed that oral estrogens caused a gain in fat mass and loss in muscle, with a decrease in IGF-1 levels. This study is more consistent with my clinical observations.

So why isn’t testosterone more commonly given for weight loss in women? The medical community actually commonly believes testosterone causes obesity. This is due to a number of studies linking upper body obesity /abdominal obesity in women to elevated testosterone levels. Once again, this is a case of blaming one hormone as a "villain". In these women, they do in fact have higher than normal testosterone levels but their whole hormonal system is out of balance. Not only do they have high testosterone levels, but they also have poor insulin sensitivity as well as high insulin levels. Often these women have a metabolic problem of insulin resistance—which is associated with obesity. There is no serious evidence that testosterone replacement therapy for women will result in greater body fat – in fact the opposite is true.

With the social stigma against testosterone and anabolic steroids in general, and it is difficult enough to get a study approved on testosterone in men. Imagine how difficult it is to get a human use committee to approve a study on testosterone in women! However, there is one study that helped to illuminate the potential for androgens to help women lose fat. Lovejoy et al, in 1996, compared the effects of nandrolone decanoate and the anti-androgen drug spironolactone on body composition in obese, postmenopausal women. The dose given the nandrolone group was low – 30 mg every other week. All women in the study were put on a calorie restricted diet (500 calories below lean mass maintenance), and were told not to change their exercise habits. After nine months, the women receiving nandrolone lost an average of 3.6 percent of their bodyfat while the placebo group lost only 1.8 percent and the spirolactone (an anti-androgen) only .5 percent. Nandrolone doubled the rate of fat loss over the placebo and the anti-androgen group barely lost any fat at all – the role of androgens in fat loss is clearly demonstrated. Even more impressive, the nandrolone group actually gained an average of roughly four pounds of lean mass in spite of the calorie restriction while the placebo and anti-androgen groups lost over two pounds of lean mass. Nandrolone also did not produce insulin resistance as androgens have been previously believed to do.

Lovejoy’s group were impressed by the ability of nandrolone to produce increased muscle mass in spite of overall weight loss. Keep in mind that dose was fairly small and only given every other week, and that these women were put only somewhat extreme calorie restricted diets without being put on a weight training program. Imagine the improvement in body composition had these women been put on a balanced exercise program and were given a high protein diet in addition to their nandrolone!

Despite the positive result, the authors cautioned against using nandrolone decanoate as a weight loss therapy. There was a mild abnormality of blood lipids and a slight increase in abdominal fat in the nandrolone group. While these side effects were minor, I believe that if testosterone was used in this study instead of nandrolone, these effects would be smaller or non-existent. I also think that daily use of a testosterone gel would be more effective than a bi-monthly shot, since the gel would keep testosterone at a more physiological and consistent level whereas injections lead to huge up and down fluctuations.

It is clear to me, both from my clinical practice and from research, that testosterone is vital for women to preserve their lean mass and to prevent obesity. Not only will testosterone help mobilize body fat and negate some of the fat storing effects of estrogen, it is also extremely effective in building lean mass in women - even at small doses. Hormone replacement therapy that only includes estrogen and progesterone but leaves out testosterone is a curse of many a women’s fat loss program. This is not only a concern for postmenopausal women. Young women should think twice about using birth control pills. Birth control pills elevate estrogen and progesterone levels while drastically lowering testosterone levels. This is reason why many women experience large gains in fat as well as a decreased libido when using birth control pills.