Male hormones


Whilst not being an expert on testosterone treatment for men, I have read a bunch of studies in order to write this post. I have a post on female hormones, and then I must have one about you men as well. Of course 😉 This is not meant to be a comprehensive overview of all things testosterone. More as a wake up call to you men with thyroid issues. Low T is a common and natural result of having low or high thyroid levels. Nothing to be embarrassed about!  In North-America, I believe there is a lot of focus on sex hormone levels. So for you living there, this post might be of little interest. But in  many countries, it’s not like that.  

There is a strong connection between thyroid and testosterone levels. For both high and low thyroid levels. It does normalize in most men after thyroid levels are again normal. But not for everybody. An then you have the age related 1 to 2% decrease a year after age 30. 

We thyroid sick already have less energy. Which will lead to lower libido. Even when our thyroid levels are optimal, we are often not as energetic as we were before getting sick.  So for us, it’s extra important to be optimal on all parameters. 

What are the symptoms of Low T? 

There are things one needs to be aware of before starting on T therapy. As far as I can see from the various studies I have looked at, they no longer think there is an increased risk of cancer in the prostate. There are conflicting findings on cardiovascular health, both negative and positive effects. If one is predisposed, or already suffer from one of these conditions, it’s another matter of course.  

You don't need Viagra, you need testosterone 😛

I find that in many areas , men’s health issues are prioritized. But not so when it comes to sex hormone replacement. Even when men’s hormone levels start going down way before women’s!   

Yet, it’s a common, normal thing for women to take hormone replacements, but not as common for men. i don’t know why. If men have a harder time with the fact of  declining levels in free testosterone, the testosterone the body can actually utilize.  The decreasing levels of free T is not only due to a decrease in hormone. It’s also due to an increase in the protein that binds T, SHBG. That means that more T is bound, and less is free to be used by the cells. 

One can only change what one acknowledges. There is no shame in being a human. We all get lower hormone levels. And we thyroid sick have two parameters influencing our hormones, our disease and age. 

But it’s not like all older men need T therapy. The Baltimore Longitudinal Study of Aging found that 20% of men over 60 suffered from hypogonadism, 30% of those over 70 and 50% of those over 80. 

Low testosterone and hypo thyroid

It’s a fact, that low thyroid levels makes for low testosterone levels in many men. This is a very thorough article from 2004 by  A.W. Meikle, on not just thyroid levels and testosterone, but growth hormone as well.  The interrelationship between thyroid dysfunction and hypogonadism in men and boys. In this study one sees a clear cut relationship between hypo and Low T: 


As you can see, the free testosterone levels are lower in those with an untreated thyroid condition than those being treated. In figur 2, the untreated have  only 45 pg/ml. Everything under 50 is too low.  The reference range is 50-224 pg/ml. Here the testosterone increases to 90 pg/ml after 30 days on thyroid medication. But what you also see, is that SHBG increases with both T4 and T3 medicine. And that is not very good, as SHBG binds the testosterone so there will be less free T for the cells to use.  

It’s not like all studies say exactly the same. But there is no doubt that low thyroid levels affect sexuality and one’s sex life in a negative direction, for both men and women. And we all know this, we don’t need any studies telling us. This meta study, a study looking at many studies, from 2020, is very good, Effect of Thyroid hormone Derangements on Sexual Function in Men and Women

It concludes, that both high and low thyroid levels lead to sexual issues in men, including erectile dysfunction. And that these issues are only partially resolved when starting on medication. It could be that this is related to dosing, on whether  one is optimal on one’s levels or not. So many hypothyroid are under dosed. In Figure 1, you see that the testosterone level, I assume bound T, increases with the amount of thyroid medicine.  One study also says, that there is a connection between the FT4 level and the severity of the sexual problems. Which makes sense, of course. But I doubt that the men in the control group all were euthyroid, that is, healthy on their thyroid levels. When I look at the study, Erectile dysfunction in patients with hyper – and hypothyroidism , I see that many of the men in the control group also had a pretty high TSH. As well as a host of ailments, and taking more drugs than the hypo group. The men in all experimental groups take statins and beta blockers.

Even with this unhealthy control group, the untreated hypothyroid have much more serious erectile dysfunction. But on the follow up 1 year later, when the thyroid sick have been given treatment for their hypo thyroidism, one see no differences between the groups. 

That is good news. It was only erectile function that was studied. We don’t know if the thyroid sick had equally high libido. I believe many of us just don’t have the energy.

Hyperthyroid and low T

Also in the case of hyperthyroid, one sees low testosterone levels. One sees sexual dysfunction in hyperthyroid men with between 48 to 77%. And this is the case also in women. 

Hyper thyroid men also have erectile dysfunction.  You will find a lot of info in this comprehensive article, The impact of thyroid Disease on Sexual Dysfunction in men and women.

Thyroid antibodies

The presence of thyroid antibodies or level of antibodies do not seem to affect sexual function in neither hypo-nor hyper thyroid men. It does affect it in women. 


All thyroid sick men should have their T level tested

When one is aware, that both high and low  thyroid levels lead to low testosterone, why do not all thyroid sick, men and women, get offered a testosterone test? And  offered T if levels are too low? And covered costs? When we know how important a good sex life is, and how important sex is for keeping a relationship? Why don’t doctors focus on this?  It’s maybe a lesser problem in some countries. I have the impression, that one is much better at hormone replacement in North- America. But I see that, only 1,67% of men in the US are on T therapy. Of course, that is all men. The number would be much higher if we said men over 50. But still, remember how many men over 60 are too low on T, see over. Here in Scandinavia we are  not in the forefront when it comes to hormone replacement, I am sorry to say.

Low T symptoms


  • No morning erection
  • Decreased libido, erectile dysfunction, issues with orgasm, less sensitivity in penis, infertility and smaller testicles
  • Less body hair, decreased need of shaving
  • Male breasts
  • Osteoporosis
  • Low energy level
  • Reduced muscle mass and strength
  • Depression
  • Slight anemia
  • Hot flashes

Some of these symptoms overlap with hypo thyroid. But if you have optimal thyroid levels, you can see what those are here. Having optimal thyroid levels is number 1. But if and when you do, and you still feel tired and without zest; have testosterone tested!

Bioidentical vs synthetic testosterone

It’s not really correct calling it bioidentical vs synthetic, because both kinds of testosterone are made from the same plants, either wild yam or soy. One puts them through a chemical process, and gets diosgenin. From this substance, one can make all kinds of sex hormones, including testosterone.

What is called “synthetic”, has an ester added to the molecule. This is done mainly to slow down the uptake. Testosterone is very fast acting, and peaks as well. One can administer testosterone in depot injections, but then it has to have esters added.  You can find very detailed information here,  The site comes up as unsafe, but that does not matter as long as you are not buying anything. It’s a site for transsexuals, but it’s the best I have found. For one thing, it’s very detailed and well informed. Secondly, it does not say which form is better. There are many sites that are very adamant as to what form is better. But the case is, there are no studies comparing the two. So I find it kind of stupid to be categorical. I am normally always in favor of bioidentical hormones. But  I believe the bioidentical one gets in gel or plasters, are much more expensive. With the gel, there is apparently a big  loss of product, only 10% seems to be absorbed. 

Effects on your health

The skeleton

T therapy increases bone density and muscle strength.  Hurrah! Low T increases fat deposits around hips and thighs. Not good.

The prostate

T therapy affects the prostate. It can grow with up to 12%. But studies have shown, that LUTS (Lower urinary tract symptoms) and urine retention do not get worse .Risk of testosterone replacement teraphy in men . In one study one found, that both LUTS symptoms improved after one year of T therapy. 

TT and prostate cancer

Earlier, it was an established fact, that taking testosterone will worsen the prognosis of prostate cancer. So prostate cancer was contra indicated for any kind of T therapy. As well as for other risk groups and afroamerican men. The latter have a prostate specific  anti gene 〈(PSA) >3 ng/mL〉.

Testosterone and the red blood cells

Testosterone increases hemoglobulin with as much as 5 to 7%. That can be beneficial for elderly men who are slightly anemic. But it can also be a problem, and lead to Polycytemia vera, that is, an increase in red blood cells which leads to thicker blood. This is the case for about 20% of men on T therapy. It can in theory increase the risk of stroke and blood clots. But this is a theoretical risk, one has not seen an increase in stroke and blood clots in men on TT. 

But because of this risk, all men starting on TT should have their red blood cells (RBC) counted before starting. As well as along the way. And if the hemochromatosis number exceeds 54%, TT should be stopped till the number normalizes. You find this info in the link over.


There are very conflicting results when it comes to testosterone and  the cardiovascular system. There were 2 studies surfacing in 2014 that indicated, T had some negative effects on the cardiovascular system. These studies have later been criticized because several of the participants were on statins, and clearly had some issues prior to the study. Studies on mice have shown beneficial effect on the heart when taking T. Testosterone does influence many risk factors positively. 


Changes in cardiovascular risk factors with testosterone replacement therapy in men with low endogenous testosterone levels. In men with low testosterone levels, testosterone therapy has been associated with a reduction in fat mass, total cholesterol, glucose concentration, serum concentrations of inflammatory markers and with an increase in time to onset of symptomatic angina with exercise (vasodilatation), muscle mass, and exercise capacity in men with symptomatic heart failure. Figure inspired from reviews of Morgentaler et al.,20 Herring et al.,11 and Oskui et al.9

This figure is taken from this very thorough review on testosterone and the heart, Testosterone, a hormone preventing cardiovascular disease or a therapy increasing cardiovascular events?  

It’s beyond the scope of this post too go to much into detail, so I suggest you have a look at that if you feel you need more info. I get the impression from what I have read, that one is not so concerned for men without prior cardio vascular disease. But if you do have such issues, discuss it with your doctor. 

Other effects of T therapy

TT and obstructive sleep apnea

Here too, studies show very differing results. But it’s worth keeping in mind, and in particular, if you have it prior to starting. 

If you have poor renal function or blood circulation, TT might not be the best option. Some men get edema.

When taking testosterone, one own’s hormone production decreases, and thereby sperm production. Follicle stimulating hormone (FSH) goes down, and FSH is what drives sperm production. This must be kept in mind with younger men. One can reduce the risk by taking a hormone, hCG-humane chorionic gonadotropin, in stead of testosterone. 

With most men, sperm production will increase after terminated treatment. but not with everyone. And many men have a low sperm count as it is today. I would have frozen some sperm. Better safe than sorry 😉

Tenderness in the breasts. Testosterone one takes can be converted to estrogen/estradiol in one’s body. This can cause tenderness in the breast area. Estradiol will need to be tested.

If estradiol increases, your weight can increase. Bus as long as the estradiol level is kept down, TT will usually lead to weight reduction.



There are some things one should bear in mind when starting TT. But all in all, I think many thyroid sick men could have a better life with some testosterone. One does get lower levels when there is thyroid disease. Even if levels normalize as one gets optimal on one’s thyroid levels, many don’t get back to pre disease levels. Plus how many aren’t optimal on their thyroid levels?

All men get lower levels with age of course. But you men  with thyroid issues  have an added disadvantage. I hope you will look into this. And if you are low on testosterone, I hope supplementing will make you feel better.




The interrelationships between thyroid dysfunction and hypogonadism in men and boys,

Effect of Thyroid Hormone Derangements on Sexual Function in Men and Women,

Erectile Dysfunction in Patients with Hyper- and Hypothyroidism: How Common and Should We Treat?,

The Impact of Thyroid Disease on Sexual Dysfunction in Men and

Testosterone guide,

Risks of testosterone replacement therapy in men,

Testosterone: a hormone preventing cardiovascular disease or a therapy increasing cardiovascular events?,



  1. Thyroid and Meabolism

    Another alternative to testosterone is DHT. It pretty much does everything that testosterone does, but the injections are not necessary. Supplementing DHT also increases the Total and Free Testosterone levels. IMHO it’s much preferred to testosterone because it does not change to estrogen.

    • L S-L


      Thank you for alerting me to this. I see from a quick google search, that there are some side effects to it, as there is to everything. It is not good for head hair, and can cause baldness. I would have to look into it before putting it in my post. I will do that when I have the time. You don’t have to inject testosterone though, you get it in many forms.

      All the best, Liv

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