Complications & Side Effects Of Testosterone Replacement Therapy


OK, so you’ve been diagnosed with symptomatic testosterone deficiency.  Perhaps you’ve tried the hypothalamus-pituitary-testes stimulation treatment pathway, but you are unlucky and are still hypogonadal.  What’s next?  Testosterone replacement therapy and you expect that you will feel years younger than you did prior to therapy.   Even feeling your own chronological age is a win, but all victories come with a price.  

Suppressing The Hypothalamic-Pituitary-Testes Axis

The first thing to know is that all testosterone therapies suppress the hypothalamic-pituitary-testes axis, and it may not recover to pre-therapy functional levels even if you stop taking testosterone, so your basal testosterone blood levels may be even lower if you ever stop therapy.  

With the axis suppressed, there is significantly reduced LH and FSH stimulation to the testes and some of their functions essentially go dormant. When that happens, they can lose volume and shrink by as much as 40-50%.  While I’ve heard cyclists say that it just means that they are harder to land on when going over a bump, and I’ve heard law enforcement officers just refer to them as smaller targets, this can be a big issue for some men.  The shrinkage can be reduced by administering a hormone called human chorionic gonadotropin (HCG).  HCG is actually made by the placentas of pregnant women and helps support the uterine environment during pregnancy.  If injected in men, it mimics the action of LH and FSH, hopefully maintaining testicular size.  

Reduced Testicular Stimulation

The second effect of the reduced testicular stimulation is the possibility of reducing the sperm count and the quality of the sperm down to the point that it can cause infertility in some men.  Note: this is a terrible method of birth control as it is unpredictable and likely ineffective for most men.  Giving HCG in larger and/or more frequent doses than for shrinkage may preserve fertility. Combining it with Clomid is being evaluated, but we will talk about this later. 

Liver Damage

Testosterone is metabolized in the liver, so like so many medications, recreational drugs, alcohol, and ingested toxins, testosterone can cause some liver damage.  Some testosterone preparations can be taken by mouth, but not all, so be cautious when discussing your therapeutic regimen with your doctor.  

Blood Flow & Heart Problems

Testosterone stimulates the bone marrow, where your blood is made, resulting in overproduction of you red blood cells.  When this happens, your hematocrit, the percentage of your blood that is cellular, rises.  The blood gets more viscous and slows down in the smaller blood vessels.  This raises the risk for blood clots that can migrate to the lungs as pulmonary emboli and cause shortness of breath and chest pain which can be life threatening.  It could also increase the risk for slow-flow strokes in the brain.  

There are conflicting reports regarding testosterone therapy and heart attack risk.   A small number of men will develop swelling in the feet or development of breast tissue.

Prostate Issues

Testosterone can stimulate prostate tissues and cause them to grow faster than they would otherwise.  If this happens, you could start having difficulty peeing and could need medications or even a prostate resection.  There is also concern that, even though it has not been shown to cause prostate cancer, raising the testosterone level in a man with a prostate cancer could cause it to grow faster and maybe spread earlier.  


Finally, as we raise the testosterone levels in the body, there is more available to the aromatase enzymes in the fat cells leading to more conversion to estradiol and abnormally high estradiol levels.  We talked about estradiol in a prior video, so please check it out if you are worried.  


Our next video discusses how we can try to preserve fertility in men who are on testosterone.  In the meantime, you can get started with our complementary self-assessment.  You can watch all of our videos and posts on Facebook and Instagram.  Thanks for your time and attention.  Bye for now.

Share Post:

Stay Connected

More Updates