Testosterone Therapy - Side Effects
Testosterone therapy, or hormone replacement therapy (HRT) as it is sometimes
called, does have occasional side effects that should be discussed with your
doctor. It is interesting because most of the fears that guys have when
considering testosterone therapy are very rare and some of the more common
things would never even cross their mind. For example, most
guys are concerned that their testosterone production will completely shut off
and/or that they will have significant testicular shrinkage. In fact, these are usually not an issue since
most men continue to produce some testosterone even when on testosterone
therapy. Good doctors test your testosterone levels after you've gone on
HRT and will make sure that your testosterone levels are not overly high.
Generally, exogenous testosterone can be considered "supplemental" and not in
the "replacement" category.
Furthermore, most of us have heard steroid horror stories of man boobs and tiny testicles and we assume that
testosterone therapy will do the same. Of course, nothing could be further
than the truth. Many steroid users have a "if a little is good, then a lot
must be better" mentality and push themselves way beyond the normal
physiological hormonal ranges. This often simultaneously pushes their testosterone
and estrogen sky high, shrinking their testicles and increasing breast/chest
tissue, respectively. (Man boobs are a rare but reported side
effect of testosterone therapy, but it is more likely a cause of low
testosterone rather than high.  )
NOTE: If you decide to try testosterone therapy, make sure that you get a
doctor that will test your liver function, PSA, total testosterone and free
every three months. Once you've stabilized, i.e. you've got the right dose, and
all tests look okay, then you can possibly go to six months depending on what
your doctor says
So are there any legitimate concerns regarding testosterone therapy? Well,
certainly, although none of them are common. Let's list some of the ones
that should be considered, however, and discussed with your doctor:
1. Fertility. Going on testosterone will very likely affect
fertility negatively. I get letters quite often from younger guys asking
if they should go on HRT. Of course, I tell them to talk to their doc
about fertility, because there somewhat of a rebound effect if you try to go off
of testosterone therapy.
So adding testosterone can affect LH (leutenizing hormone) and FSH (follicle
stimulating hormone) levels. LH governs testosterone production in the testes
and FSH is responsible for spermatogenesis, i.e. creation of the sperm. (See my
link on Fertility for more information.)
But even you older guys that are in a serious relationship with a Younger Woman
may need to consider this as well.
Apnea. If you have
sleep apnea, some studies show low testosterone can worsen that
condition.  Again, though, sleep apnea is very correlated to weight.
Some dropping some weight, which can boost testosterone directly, may solve your
apnea, but work with your doctor in this situation. (By the way, not all experts
feel the apnea-HRT connection is valid.)
3. Acne. Some guys get the joy of going through a
second puberty when on testosterone. Again, this is uncommon but a
possibility in sensitive individuals. See my link on Acne for details
4. Hair Loss. Some have reported hair loss as a side effect,
although this does not seem to be common and is difficult to prove. Some of the testosterone delivery
systems, such as scrotal patches, deliver higher levels of DHT, the primary
culprit in typical male pattern baldness.
5. Soy Allergy. Some of the topical preparations are actually
manufactured from soy and thus should be avoided by those with a soy allergy.
6. Severe Health Considerations. There was a recent small
study on 219 senior men with poor health (diabetes, obesity, high blood
pressure, etc.) and poor mobility that showed a significant increase in
cardiovascular events when compared with the placebo group. The study was
halted and researchers basically said that no conclusion could be drawn due to
the small study size. However, you should discuss this study with your
doctor, especially if you are an older, sedentary male with a significant health
Liver Problems. One last thing: almost all testosterones given in
testosterone therapy are very well-tolerated by the liver, but you want a doctor
that will test your liver function just to play it ultra safe. Liver issues are
associated almost exclusively with the old-line oral testosterones that were
difficult to metabolize.
8. Enlarged Prostate. One uncommon side effect occasionally
reported with HRT (Hormone Replacement Therapy) is BPH (enlarged prostate).
9. Thickened Blood. A recent meta-analysis found that testosterone therapy
significantly increased hemoglobin and hematocrit, which makes blood more thick
and likely to clot. 
10. Lowered HDL. The same study above found that that testosterone
therapy was associated with a small decrease in HDL as well. 
NEWS FLASH: A recent Newsweek [Nov 9, 2009, p. 56f]
article covered how some guys on HRT are either ignorant or being negligent. They are applying the gel to their
chest, shoulders and/or arms and then are in direct skin-to-skin contact with their children (or
This is very serious indeed: a young child can be developmentally affected
by repeated exposure to significant amounts of testosterone, including potentially the brain. In a young boy, for example, the lines
on the scrotal sac can be altered and pubic hair thickened and grown.
was just talking with a pediatric endocrinologist about this and it is
imperative that guys wash their hands and keep any areas of application covered. He had only noticed
problems in guys who were careless and/or ignorant of the risks involved. There
have been enough reports of this problems that the FDA is currently forcing a
generic version of Testim to undergo "hand washing studies" to make sure that it
is as safe in this regard as the original. Furthermore, even the original
products may have to carry a "black box" warning label. Keep your family
If you are interested, you should also read my
Overview of HRT and common Methods of
Testosterone Delivery (such as gels and injections). These links should
give you a lot of good talking
points with your doctor.
Clin Endocrin (Ox),1988;28:461-470
4) J Clin Endocrinol Metab, Jun 2010; 95:2560-2575, "Adverse Effects of
Testosterone Therapy in Adult Men: A Systematic Review and Meta-Analysis"