Relationship Between Testosterone Levels and the Thyroid

Testosterone is a hormone produced by ovaries in women and testicles in men.

It is often considered a male sex hormone, but its deficiency can cause problems in both – males and females.

In this article, we’re going to talk about the functions of testosterone and how this hormone relates to thyroid health – especially underactive thyroid or hypothyroidism. We’re going to discuss ways to regulate testosterone levels naturally and with the help of medications.

The thyroid gland produces the thyroid hormones triiodothyronine (T3) and thyroxine (T4) which regulate many processes in our bodies, primarily hormonal balance, protein synthesis and metabolic rate.

The thyroid gland is located in the throat, at the base of the neck. If we perform a cross-section of the throat, inside we could find the hyoid bone – or the tongue-bone, the larynx, and the butterfly shaped gland underneath the larynx which is the thyroid.

The thyroid problems can be caused by iodine deficiency, other nutritional issues, genetics, etc. The thyroid gland is most commonly affected by two diseases.

Hyperthyroidism is a condition when the gland produces unusually high amounts of thyroid hormone. The most common cause for this condition is an autoimmune disorder called Graves’ disease.

Hypothyroidism is an opposite disease – it’s a state of insufficient production of the thyroid hormone. Together with iodine deficiency, the main cause of primary hypothyroidism is Hashimoto’s Thyroiditis – an autoimmune thyroid disease. Drug therapies are also a common cause for this condition.

Checking the Thyroid – Self Test

One of the ways to check whether you have an underactive thyroid is to measure your basal temperature once a day.

The basal thermometer should be sensitive enough to measure temperature to one decimal point. These are widely available in pharmacies and mostly inexpensive.

The temperature should be taken once a day for seven days. The key is to take the temperature before taking any food or drink, and prior to going to the bathroom.

Write down the measured temperature every day and add up the numbers, then divide them by the number of days, which is seven.

Normal body temperature is between 36.4°C – 36.7°C or 97.6°F – 98.2°F. If your measured average temperature is below this range, you may have underactive thyroid.

If you feel like your symptoms may mean your thyroid is not working properly – visit the doctor as soon as possible. Many doctors attribute the symptoms to aging only. Make sure that you get all the necessary tests. Insist if needed!

Testosterone Levels and Hypothyroidism

What is the role of testosterone in thyroid health? Well, this “male sex hormone” plays a big role, per several research studies.

Primary hypothyroidism can reduce free testosterone levels and the opposite can be true.

Experts mainly associate hypothyroidism or low thyroid function with lower testosterone levels, and elevated thyroid function – or hyperthyroidism – with increased testosterone.

When it comes to hypothyroidism, we usually think of women since they are eight times more likely to develop this condition, but males are affected too.

With hypothyroidism, the thyroid gland doesn’t emit enough thyroid hormone for our bodies, and the body relies on this hormone to function properly. Without it, a person can experience several physical and mental issues.

Some people have no symptoms regarding the hypothyroidism. Same as testosterone levels, thyroid hormone levels decline in production with aging.

Without a functional thyroid, our bodies wouldn’t be able to break down proteins, or process carbohydrates and vitamins.

When the thyroid is functioning well, the body is usually warm, able to cope with temperature changes, but when the thyroid is underactive – the body is often very cold.

Besides body being cold, some of the most common hypothyroidism symptoms include:

  • Fatigue
  • Sudden weight gain
  • Low blood pressure
  • Erectile dysfunction
  • Depression
  • Arrhythmia
  • Elevated cholesterol
  • Constipation
  • Muscle tension
  • Hair loss
  • Reduced immunity to infections

These symptoms can be caused by many other conditions, but having several of them at the same moment should be the alarm to check the thyroid.

Even though hypothyroidism is commonly diagnosed in women, there are men who suffer from this condition and the symptoms above are also valid for them.

Few of the symptoms that are more common in men include losing hair (including eyebrows and body hair) and decreased libido.

Science behind Hypothyroidism Effect on Testosterone

Primary hypothyroidism often causes low luteinizing hormone (LH) to gonadotropin-releasing hormone (GnRH). The latter is produced in the part of the brain called hypothalamus, and it signals when to release luteinizing hormone.

When it’s low (like in men with underactive thyroid), LH won’t do its job like it’s supposed to, and the function would be stimulating the production of testosterone in male genitalia. This is the most obvious connection between underactive thyroid and low testosterone. As the male genitalia decrease the testosterone production, the final result would be hypothyroidism.

Lab Tests

The best and the required method of testing for low testosterone and hypothyroidism is blood analysis in the lab. You will give a sample of your blood, and several tests will be run. The technician will check the testosterone levels by measuring free and total testosterone levels.  Hypothyroidism is measured with thyroxine (T4) and Thyroid-Stimulating Hormone (TSH) readings.

Hypothyroidism often causes elevated prolactin, which can lower testosterone levels. Elevated prolactin levels are caused by increased TRH, which is a response to underactive thyroid.

The optimum average amount of testosterone for men is 550ng/dL.

Everything below this number is considered low.

Women have significantly lower range – 15 to 70ng/dL, and menopause can lower this by half. This is why many doctors fail to differentiate hypothyroidism from simply aging.

After the menopause, the testosterone production in women will decrease, but it’s not that serious since 75% of the production comes from areas like adrenal glands and peripheral conversion.

Men start to notice a decline in testosterone levels around the age of thirty, and it increases by 1 percent every following year. Most males won’t notice changes, but some of them will; and they will realize their sexual appetite, energy, and metabolism will start to decrease and suffer.

Treatment for Low Testosterone and Hypothyroidism

Often testosterone levels and underactive thyroid can be treated with a healthy diet which commonly includes dietary changes or supplementing strong thyroid healthy herbs. There are various other ways of improving thyroid functionality naturally as well.

However, for more serious conditions, nutritional changes are not an option and medication is often used, such as Synthroid or Armour Thyroid.

The usual treatment for low testosterone is a replacement therapy. Women are often given transdermal creams, and men have much more options including creams, gels, patches and of course – injections.

Natural ways to improve low testosterone and hypothyroidism include more sleep, a better diet, exercising, and less stress, among others. “A Better diet” is far away from restricting and lowering the caloric intake. Our article on the best and worst foods for your thyroid may help in this regard. Stress increases cortisol levels – which is a stress-related hormone which interferes with testosterone and lowers its amount in the body.

Regarding sleep – aim for at least eight hours of good night sleep – it will help to maintain optimal secretion of hormones, including the testosterone.

Complications if Hypothyroidism is Left Untreated

When a person has low testosterone and hypothyroidism that are not cured, some of the complications include:

  • Heightened risk of stroke
  • Heightened risk of heart attack
  • Difficulties in pregnancy that could affect the unborn child
  • High cholesterol

Hypothyroidism can affect life in a negative way, making you very tired, moody, taking all the energy – basically preventing you get up in the morning and lead a normal life. Having hypothyroidism can look like you are depressed to those around you. Doctors often misdiagnose patients and provide therapy for depression – leaving the hypothyroidism untreated, thus complicating the condition even more.

Some people might cope with underactive thyroid for years without knowing it’s an actual medical condition that can be treated. Without sufficient testosterone and thyroid hormone flowing in the body, you might experience fatigue, weakness and be unable to function normally.

A lot of people believe it’s all in their mind. Relief is available; people just need to be informed about their possibilities.

Besides hypothyroidism, low level of testosterone can be the cause for issues like diabetes, osteoporosis, heart disease, and dementia, among others. It’s extremely important to consult a reliable and knowledgeable people to discuss the best ways to increase testosterone production – and find a good solution for your body.


  1. “Let’s not forget all the men with hypothyroidism”, David Borenstein, MD, Manhattan Integrative Medicine
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