Low Testosterone (Low T) 101: A Primer

Testosterone is the main sex hormone in males and plays a critical role in the development of male reproductive tissues, sex drive, voice deepening, increased bone and muscle size, the growth of body hair (e.g. especially on the face), and aggression, among other functions.

The main sex hormone in females is estrogen, which plays a critical role in the development of the female reproductive tissues, sex drive, breast enlargement, hip widening, and the development of rounded and softer facial features (compared to men), among other functions. Essentially, testosterone is what makes a man a man and estrogen is what makes a woman a woman.

Some may be surprised to know that men and women each produce testosterone and estrogen. Men naturally have higher levels of testosterone whereas women naturally have higher levels of estrogen. Sometimes, however, the natural levels of hormones in the body go awry and this can lead to significant clinical problems.

One common example of a hormonal imbalance in men is low testosterone, sometimes referred to as “low T.” When one considers what normal levels of testosterone in the body do, it is not surprising to learn that low testosterone in men can lead to loss of body hair, decreased sex drive, infertility, decreased bone and muscle mass, and erectile dysfunction (ED).

As noted by WebMD, low testosterone can also result in other problems such as decreased energy, difficulty concentrating, and mood changes (e.g., depression). Some of these symptoms can be directly related to the effects of low testosterone but they can also be related to indirect effects of low testosterone due to difficulty psychologically coping with manifestations of the condition. For example, a man may become depressed because he is having difficulty conceiving a child and/or also losing his hair.

There are many possible reasons for low testosterone including genetics, obesity, testicular injury, medication side effects, and diabetes mellitus, among other factors. If you suspect that you have low testosterone, or if your doctor does, it can easily be tested with a simple blood test.

Once low testosterone is detected, the next step is to decide if treatment is needed and if so, how to treat it. Treatment is most likely to be needed if low testosterone is causing clinically significant symptoms. Treatment often involves testosterone supplementation therapy (a type of hormone replacement therapy). One such treatment is testosterone cypionate (review here) which comes in an injectable form. Other testosterone supplements come in different forms such as skin patches, gel rubs, or tablets that dissolve on the gums.

As with any treatment, side effects of testosterone treatment can occur, which is why ongoing communication with a physician is very important. If you believe that you have symptoms of low testosterone then be sure to talk to your physician about getting tested and explore your treatment options if it is determined that you have low T.