Testosterone and Your Thyroid
STEP 3. Many men start yawning almost immediately when you bring up anything to do with the thyroid, but
that really should not be the case. The thyroid is somewhat like the floor pedals
(accelerator/brake) on your car, since the thyroid either
slows down or speeds up hormones and metabolism. For example, low thyroid function (hypothyroidism) is associated with
lower testosterone and elevated thyrooid function (hyperthyroidism) with increased testosterone.
Now on this page I am going to concentrate on hypothyroidism for the simple reason that the symptoms are so common on the Peak Testosterone Forum.
A very high percentage of men coming to the forum have the classic symptoms of low thyroid function such as fatigue, poor libido, depression
and erectile dysfunction. (For more information on the latter, see my link on
Erectile Dysfunction and the Thyroid.) From my
perspective, it is almost an epidemic and I want to cover some of the basics below.
However, let's start by looking at the evidence that hypothyroidism actually
1. Decreased LH (Leutinizing Hormone). Researchers have found that
hypothyroid men have a "subnormal response of luteinizing hormone (LH) to
gonadotropin-releasing hormone (GnRH) administration."  Of course, GnRH is
produced by the hypothalamus, which then triggers LH. LH, in turn,
stimulates the testes to produce testosterone. This means that
hypothyrodism sabotages the first step in the testosterone production assembly
2. Decreased Free Testosterone Levels. The same study and others
have noted that hypothyroid
men tend to have lower free testosterone concentrations. 
3. Treating Hypothyroidism Often Increases Testosterone. A further sign of
hypothyroidism's causal effect on low testosterone is the fact that treating men
with thyroid medications can actually boost their testosterone back to normal.
 One study found that giving hypothryroid hypogonadal men thyroxine (T4)
almost doubled their free testosterone levels! 
4. More Than Doubling Total Testosterone. Normally one will not get a
huge boost in testosterone from fixing his hypothyroidism. However, huge
gains are possible as evidence by a case study of one man with both severe
hypothyroidism and hypogonadism.  This individual was able to increase his
total testosterone by 150% just my standard thyroid treatment. His
testosterone was still pretty low - in the low 400's - but it was an impressive
STEP 2: TESTOSTERONE and HYPOTHYROIDISM
a) Assess Your Symptoms. Start by taking a quick look at these
symptoms. Do any of them apply to you?
- Low libido
- Erectile Dysfunction
- Elevated cholesterol
- Dry skin
- Inability to concentrate and remember
- Low blood pressure
- Missing Outer Eyebrows
- Feeling cold
- Weight Gain
Of course, these symptoms can have many other root causes. However, when
you see that you have several of them, it could point to hypothyroidism.
Also, notice that there are some symptoms that overlap with hypogonadism (low
testosterone) and this can undoubtedly be partially explained by the fact that
hypothyroidism can cause low testosterone as mentioned above.
So how do you determine if you have low thyroid function? Well, this is
where it gets interesting. At least here in the U.S., endocrinologists are
more often than not extraordinarily conservative. As an example, they are
the most reluctant to treat men for low testosterone. They do this by
creating a very rigid definition of what constitues hypogonadism based on a very
low testosterone threshold.
It is no different with hypothyroidism. Again, from what I have seen,
endocrinologists are very reluctant to treat men (and women) for hypothyroidism
as well. Not all endocrinologists (and PCPs) are like this, but certainly a
percentage. What has emerged from the discontent over this are alternative health
protocols based on treating
subclinical hypothyroidism? Basically, it refers to low
thyroid function that responds to treatment even though it is technically not
clinical hypothyroidsim by the "old school" definition. Many practitioners
- "new school" endocrinologists, naturopaths, anti-aging doctors, etc. - have
broadened their protocols for hypothyroidism and we will discuss how they do
some of this monitoring and testing below.
Testing for Subclinical Hypothyroidism
Let's look at some of the ways that are currently being used to find low thyroid function that
are "out of the box":
1. TSH Between 3 and 5. TSH is the signaling hormone released from
the pituitary that signals the thyroid to start producing more thyroid hormones.
In some kinds of hypothyroidism (and in a manner analagous to rising LH in
primary hypogonadism), TSH begins to rise. The old school definition was a
TSH > 5.0 to define hypothyroidism. However, a recent study showed that
this should be revised down to 3.0. (From what I have read, the "ideal"
TSH is roughly between 1 and 2.) On a practical level, this means that
many patients with a TSH between 3 and 5 would receive treatment from a
different physician who was using the more recent, updated number. For a
more detailed explanation, see this article.
2. Thyroid Antibodies. What many men do not know is that the most common form of hypothyroidism actually is autoimmune in
nature and is called Hashimoto's Thyroiditis. Basically, the body's own immune system attacks the thyroid and slowly destroys it over the years.
This can usually be identified by a couple of simple thyroid antibody tests. The two most critical tests are Thyroid Peroxidase Antibodies (TPOAb) Thyroglobulin Antibodies (TgAb).
For thresholds see this Medscape article.
3. Elevated rT3 (Reverse T3). Most men know that the two primary thyroid hormones are T4 and T3. TSH actually triggers the production
of these in the thyroid at a ratio of 17::1, i.e. 17 T4 molecules for every one T3 molecule.
A significant amount of T4, however, is converted into T3 in various body tissues.
And, to further complicate matters, the liver converts about 20% of your T4 into
something called Reverse T3 (rT3). rT3 is part of the body's feedback
mechanism, but in some people it becomes elevated. And, as its name
implies, rT3 reverses normal thyroid function, i.e. can make you hypothyroid.
Again, someone with fairly normal TSH numbers but high rT3 can experience
hypothyroid symptoms. Fortunately, you can test rT3 and see if this a problem
4. Free T3 and Free T4. The thyroid hormones are similar to
testosterone and estradiol in the sense that they have a bound and unbound form.
If you have low or lowish free T3 and/or free T4 values, this can indicate
hypothyroidism. And it makes sense as it is showing a low output of
hormones from the thyroid.
There are other tests as well, but these have been quite common on The Peak
Testosterone Forum and seem to be in wide use.
In my opinion, this is a good thing and I am sure many men have been helped by it.
Just as in the case with low testosterone, there are a number of approaches that have been used to overcome hypothyroid issues. Here are a few of them:
1. Go Natural. Instead of just running off and taking thyroid medication, you may want to consider the fact that in some cases low thyroid issues
can be reversed by
relatively simple lifestyle changes alone. This may be part of these reason that "going natural" can sometimes increase testosterone levels and improve
erectile function. Here are a few examples:
--Lower Stress. Excess cortisol actually inhibits the conversion of T4 to
T3, and result in smaller amounts of T3 and larger amounts of rT3. In other words, stress and the elevated cortisol levels that often accompany it can
literally turn you hypothryoid. Instead of going on thyroid hormones, why not eliminate the stress? I have many suggestions that I discuss
in my Summary Page on Stress and Cortisol.
--Dieting. If you cut your calores too much, you can make yourself hypothyroid. Your body compensates for the loss of calories by dropping T3 output,
something I discuss in my link on Why Crash Dieting Just Does Not Work. So, if you're cutting calories and
are hypothyroid, it may be that you will normalize after you restore baseline calorie levels. Discuss with your physician.
--The Two I's: Inflammation and Infection. As mentioned, Hashimoto's is definitely an autoimmune disease which is usually a result of elevated inflammation
levels. And, as discussed in this article, inflammation can also induce hypothyroidism in other key ways as well. The bottom line is that I think it would be
prudent to check your CRP (C-Reactive Protein) levels and make sure they are less than 1.0 along with any other key markers. For more information on the subject,
see my link on Natural Ways to Lower Inflammation. Keep in mind that latent infections can raise inflammation, including things like
gum disease and Super Bugs. So get a thorough checkup and keep digging.
2. T4 Only or T3 Only or Both. One thing that will you notice with thyroid medications is that "it is more art than science." Basically, some
patients do well on T4 only. Some do well on T3 only. And some do well on both. It sometimes takes some experimentation.
3. Dessicated Thyroid. Some patients do much beter with "dessicated thyroid" products which are basically dried pork and beef thyroids. These will
have a combination of T3, T4 and rT3 along with a couple of other thyroid hormones. This wide range of hormones is considered by some to be more "natura" and probably
accounts for the reason that dessicated thyroid works well in some patients and poorly in still others.
1) Thyroid, 2004, 14 Suppl 1:S17-25, "The interrelationships between thyroid
dysfunction and hypogonadism in men and boys"
2) Horm Res, 1990, 34:215–218, "Reproductive Endocrine Functions in Men with
Primary Hypothyroidism: Effect of Thyroxine Replacement"
3) Clinical Endocrinology, Feb 2000, 52(2):197–201, "Testicular dysfunction in
men with primary hypothyroidism; reversal of hypogonadotrophic hypogonadism with
4) Cleveland Clinic Journal of Medicine October 2012 vol. 79 10 717-725, "Male
hypogonadism: More than just a low testosterone"