From: http://www.webmd.com/content/pages/16/99337.htm
Before you go and get your testosterone levels tested, be sure you know the facts:
Laboratories vary in how they perform testosterone tests. To be sure
of the result, have all your testosterone tests done at the same
location at roughly the same time of day. (Hormones fluctuate
throughout the day, so testing at about the same time is best.)
Testosterone levels are most often measured with blood tests, but some
centers utilize saliva tests as well.
According to Henry Ritter, MD, a urologist from Atherton, Calif., the
most useful number to know is the "free testosterone" (or bioavailable
testosterone). The "total testosterone" reflects free and bound
testosterone. Bound testosterone is not available to boost libido
because it is linked to proteins, such as albumin and sex hormone
binding globulin, according to John E. Gould, MD, PhD, associate
clinical professor of urology at the University of California at
Davis. Gould also recommends getting the free testosterone number.
Different labs measure free testosterone differently. But ranges they
consider "normal" generally fall between 260 nanograms/deciliter to
1,000 ng/dL (or 2.6 nanograms/milliliter to 10 ng/mL). Since
physicians and laboratories have only recently begun to recognize the
importance of testing free testosterone, you may have to lobby to get
the test. If you are unable to get that reading and are forced to
stick with total testosterone, learn the range of normal for your lab.
Normal ranges for men usually are between 250 ng/dL to 1,200 ng/dL of
blood (2.5 ng/mL to 12 ng/mL).
Keep in mind that these ranges are created by testing many men without
much attention to their relative level of sexual function. Men whose
testosterone level is in the lowest 20% of the normal ranges above may
not feel much sex drive at all. In my clinical experience as a sex
therapist, men with total testosterone readings in the low 400s tend
not to have much sexual drive even if they are in fulfilling
relationships. Ritter says that even some men in the 600s do not feel
that much drive when other things are equal, and he prefers to see
numbers in the 700s. Throwing things into further confusion, says
Gould, is the fact that sometimes free testosterone will be low when
the total testosterone is high and vice versa.
One of the problems with all this measuring, Ritter says, is that very
few men have baseline measurements of their testosterone (free or
total) during the time their sex drive was normal. So there is no way
to know whether they have experienced a relative decrease. Also, there
are probably men who would test low but who would not complain at all
about the strength of their sexual drive. Clearly, determining the
best testosterone level for you is not an exact science since a key
component involves personal expectations about sexuality, a very
complex matter.
According to Gould and Ritter, testosterone does not affect sexual
function, only sexual drive. (And it is certainly not the only
component of sexual drive.) So look for other explanations and
solutions if erection difficulties or problems with the timing of
orgasm occur.
If you do find a low level of free testosterone in two separate
readings from the same laboratory, Ritter and Gould recommend getting
several other lab tests to determine if you're a good candidate for
testosterone supplements:
baseline liver function, or LFT
complete blood count, or CBC
prostate-specific antigen, or PSA
prolactin level
luteinizing hormone level, or LH
digital rectal exam
follicle stimulating hormone test, or FSH (optional)
Taking testosterone is dangerous only if you have certain medical
conditions. For starters, it's important to check your liver function
before, and at regular intervals during, a
testosterone-supplementation program. If there is a negative impact to
the liver, it can be reversed by discontinuing the testosterone, says
Gould.
According to Ritter, prostate cancer either in your own history or
your immediate family history rules out taking testosterone. An
enlarged prostate that isn't cancerous, however, is not a deal-breaker
-- a PSA test will let you know where you stand. The other tests help
rule out other hormone problems: An abnormal LH test or prolactin
level, says Gould, will alert your physician to check your pituitary
for a malfunction or tumor. FSH testing can help determine if your
sperm production is low.
Other potential risks: So far, no study provides solid evidence that
taking testosterone will cause hypertension or a substantial increase
in cholesterol levels. It may cause a slight rise in blood pressure or
"bad" cholesterol (low-density lipoprotein), but generally not to
levels that are significant or irreversible.
Currently, testosterone can be administered by injection, pill, or
skin patch. Most physicians favor either the injection or patch
because the pill has more potential for negative medical consequences.
Ritter states that about 10% of men who use pills develop a condition
known as chemical hepatitis and must discontinue. Gould says that
pills are generally "just hard on the liver."
With injections there are infrequent liver problems and they are
generally reversible. The two negatives: the annoyance of getting a
shot every two weeks to three weeks, and the "spike effect," which
gives a man a sudden boost of testosterone that usually wears off by
the time of the next injection.
The skin patch also causes liver problems only infrequently and has
the added advantage of eliminating the spike effect because the same
amount of testosterone is absorbed through the skin each day as a new
patch is applied. The patch approach is slightly more expensive than
injections, but involves no needles.
Men over 50 would be wise to have an annual prostate check anyway,
even if they do not decide to supplement testosterone.
If a man's relationship is fulfilling, but his sexual desire is low,
testosterone supplementation is a consideration. It won't, however,
turn a nonsexual relationship into a sexual one if there are issues in
the relationship that should be addressed. |
