What Testosterone Is For

Testosterone isn't only about sex drive, although a low libido is one of the more noticeable signs of having a low testosterone level. Testosterone also contributes to muscle strength, bone strength and density, sense of well being, red blood cell mass, adequate sperm count, sexual performance and penis growth during puberty.

Who Has Low Testosterone Levels?

Depending on at what point testosterone levels are described as undesirably low, between 4 and more than 40 million men in North America alone suffer from this problem. 1% of men between ages 20 and 40 have it. That number rises to 7% for those ages 40-60, 20% for ages 60-80, and 35% for men older than 80. In other words, it decreases by 1-2% per year after age 40. Only about 5% of these men seek treatment.

While medical science has determined that while a man’s total (protein-bound) testosterone levels remain relatively stable over time, his bio-available (free) levels gradually decline at an alarming rate of two percent each year beginning at age thirty. This means that a man in his sixties is functioning with only about forty percent of the testosterone he had in his twenties.


Some of the causes of testosterone deficiency are: aging (testosterone levels begin decreasing at the age of about 40); certain chronic illnesses; certain drugs, including chemotherapy drugs; congenital absence of testes; congenital deficiency of GnRH (gonadotropin releasing hormone); excessive consumption of alcohol; excessive training; illness; Klinefelter's syndrome (a genetic disorder, easily diagnosed with a blood test); mumps; physical inactivity; pituitary tumour, surgery or radiation to the head; smoking; stress; trauma to or surgery of the testes; undecended or retractile testes; varicocele; vasectomy (in rare cases); and the use of both prescription and "recreational" drugs. 

Symptoms & Effects

Some of the symptoms of having low testosterone levels, or hypogonadism are: a loss of muscle tone (or a difficulty in gaining this), weight gain particularly around the abdomen, general weak- and tiredness, having difficulty recovering from exercise, a lowered sex drive or sexual dysfunction (erectile dysfunction in particular), depression, irritability and apathy, difficulty coping with stress, sleep disorders, reduced muscle mass and strength and decreased bone density

The symptoms of low testosterone are not always useful in diagnosis, however. All of the symptoms are sometimes caused by other things. If you are suffering from a majority of these symptoms, however, testosterone deficiency is certainly something you should consider.

Men with hypogonadism are at great risk of suffering from heart attacks. Having a low blood insulin level helps to prevent such attacks, and it is the men with the highest testosterone levels who have the highest insulin levels, although the correlation between these facts is not known. 

Because low testosterone decreases bone mass, men who suffer from it may develop osteoporosis, leading to an increased risk of bone fractures, particularly in the hip and spine.

Some men with hypogonadism have enlargement of the breast area, known as gynecomastia

Hypogonadism during childhood results in lack of puberty and/or infertility.  

As men age from 50 to 70, their testosterone levels drop more than 40%, causing them to become fatter, and less sexual, muscular and assertive, and have smaller, weaker bones.  Most men after the age of 70 have low testosterone, decrease in muscle strength and decreased bone mass. This observation has lead some physicians to wonder if low testosterone level may, in part, be responsible for the process of aging and whether testosterone replacement can serve as anti-aging hormone therapy. At present, there is a lot of controversy on this issue. Testosterone therapy in older persons, in particular, may promote growth of prostate cancer and may also reduce HDL (good) cholesterol and therefore, may put these people at risk for heart disease


An endocrinologist is the specialist you need to consult for the proper diagnosis of low testosterone and its underlying cause. However, St Louis University has put together the following self-screening questionnaire of ten basic questions to help men identify symptoms of low testosterone. 
  1. Do you have a decrease in libido (sex drive)?
  2. Do you have a lack of energy?
  3. Do you have a decrease in strength and/or endurance?
  4. Have you lost height?
  5. Have you noticed a decreased "enjoyment of life?"
  6. Are you sad and/or grumpy?
  7. Are your erections less strong?
  8. Have you noticed a recent deterioration in your ability to play sports?
  9. Are you falling asleep after dinner?
  10. Has there been a recent deterioration in your work performance?
If you answer "yes" to question one or seven, or you answered "yes" to three or more of the other questions, you may be a candidate for TRT. If this is the case you should see your doctor with the questionnaire and ask to have your testosterone (free and total) levels tested. 

Although all the symptoms listed above tend to indicate a low blood testosterone level, there is only one way to know whether a man has low testosterone: repeated blood tests. These should be done in the morning, when testosterone levels are usually highest, and they should look for free testosterone as well as total testosterone. If the ratio of free to total testosterone is low, prolactin, which can suggest a rare brain tumor, should also be checked.

There is also a home testosterone level testing kit which tests the levels present in your saliva. Salivary testing is less invasive than blood testing, and some researchers claim it is more accurate in testing bio-available testosterone and a number of other key male hormones than the blood tests.

Treatments The treatment of low testosterone levels is to increase the testosterone in the blood. Testosterone is delivered to the body in a variety of ways. Whatever the form, it's important to check blood levels to adjust the dose; there's no simple formula. 

Testosterone can be delivered by an adhesive patch which has been impregnated with testosterone being applied to the forearm or inner thigh. This patch needs to be applied daily, and testosterone levels regularly checked. Some men who use this method develop a skin irritation.  
It can be delivered by a gel which is applied to the inner thighs or scrotum. Again the gel must be applied daily and the testosterone levels monitored carefully. 
Testosterone replacement has traditionally been done with intramuscular injections, usually every two weeks. Intramuscular injections can be inconvenient and also cause peak and trough levels of testosterone. Testosterone injections can make older men with low blood levels of testosterone more interested in making love. The only reported significant side effect is an increase in the concentration of red blood cells that could cause clots.  
There are also testosterone replacement implants and pills available, but I have been unable to discover much about them, apart from the fact that the pills are not allowed to be used in North America.