By Mike Kocsis | 3 minutes read | Last updated: September 10, 2025 Categories: Testosterone
Medically Reviewed by Dr. George Touliatos
Testosterone is a vital hormone that is responsible for the development of male physical characteristics. In men, testosterone is primarily produced in the testes, but several parts of the body have to work together to ensure that testosterone is produced correctly and the body remains healthy.
In this guide, we’re going to look at how the hormone is produced in men, starting with the brain, and then moving on to the testes as well the other parts of the body. Stay tuned!
Brain
The hypothalamus is the part of the brain responsible for homeostasis, or the internal balance of the body. This includes the production of hormones for the endocrine system, as well as linking the endocrine system to the nervous system.
It is the hypothalamus that initially triggers the release or inhibition of hormones.
In the case of testosterone, it is the hypothalamus that tells the pituitary gland it must release hormones to stimulate testosterone production. To do this, the hypothalamus releases gonadotrophin-releasing hormone.
Testes
The two different hormones released by the pituitary gland serve different purposes in reaching the testes.
FSH is responsible for sperm production, whilst LH specifically stimulates the production of testosterone. It does this by influencing a special type of cell called a Leydig cell. When Leydig cells are activated, they begin to convert cholesterol into testosterone.
Most cholesterol reaches the bloodstream through diet, particularly in foods such as bacon and eggs.
Cholesterol is produced by the testes if there is not enough in the bloodstream, but this is less effective and can inhibit the Leydig cells. It is cholesterol absorbed from the bloodstream that is most important for testosterone production.
There is a small amount of testosterone produced by the adrenal glands, only about 5%. The other 95% in men comes from the testes.
In women, the majority of their (lower level of) testosterone comes from the ovaries, though again some is produced in the adrenal glands.
Pituitary gland
Many of the hormones that control the endocrine system have their origins in the pituitary gland (a pea-sized gland found at the base of the brain).
As well as the testes, the adrenal glands and thyroid gland are at least partially controlled by the pituitary gland.
The hypothalamus gives the instruction, but then the pituitary gland actually releases or inhibits the hormones.
When the hypothalamus tells the pituitary gland that the testes need to produce more testosterone, the pituitary gland begins releasing other hormones, known as gonadotrophic substances. These include follicle-stimulating hormone (FSH) and luteinising hormone (LH).
LH, in particular, will compel the testes to produce more testosterone. If the level rises by too much, the hypothalamus will tell the pituitary gland to stop producing LH.
Bloodstream
Newly produced testosterone is sent from the testes to the bloodstream and carried to where it is needed.
Some will become inert when it attaches to various proteins, whilst a small amount will freely travel to areas of the body where masculine characteristics or secondary sexual characteristics develop.
If the hypothalamus decides that testosterone in the blood has achieved an appropriate level, it will reduce its production of gonadotrophin-releasing hormone, which in turn will cause the pituitary gland to reduce its production of LH. This production and reduction form an ongoing cycle.
Incorrect levels of testosterone
Sometimes, the body will not produce the correct amount of testosterone.
Too much testosterone can cause early puberty in younger children, sometimes leading to infertility. Conditions that cause excess testosterone production include congenital adrenal hyperplasia, androgen resistance and ovarian cancer. The use of anabolic steroids can also interfere with testosterone levels.
Low testosterone can delay puberty, as well as have a negative effect on muscle mass, bone density, body fat, libido and mood. Otherwise known as male hypogonadism or testosterone deficiency.
Some reduction in testosterone production is normal as a man ages. However, if the low-t symptoms (mood swings, poor concentration, low sexual function, etc.) persist, you may need to be treated with a testosterone treatment called testosterone replacement therapy (TRT).
If you feel you may be suffering from low testosterone levels, dont hesitate to get in touch with our specialised doctors by hitting the contact us button! They can help you restore normal levels of testosterone and improve your overall health.
What is testosterone made of?
Like other androgens, testosterone is also a steroid hormone derived from cholesterol through a complex biosynthetic pathway involving several intermediates.
The precursor molecule cholesterol is converted to testosterone in testes with the help of various enzymes. During this process, dehydroepiandrosterone (DHEA) and androstenedione are the last two intermediates that are transformed to the male sex hormone testosterone.
How is testosterone released?
Testes release the major sex hormone testosterone into bloodstream after getting a message from the brain.
Once testosterone enters the bloodstream, 95% or more of it binds to proteins like sex hormone binding globulin (called bound testosterone) while only 5% or less of the circulating testosterone stays free (called free testosterone).
Free testosterone travels to the tissue where it’s needed and performs its role there. Bound testosterone is released when needed. Both free and bound testosterones are collectively called total testosterone, which is measured through blood tests.
Normal testosterone levels in adult males range from 6 -27 nmol/L. Low or abnormally high testosterone levels affect thousands of men every year. They may happen due to prostate cancer, testicular tumors, primary hypogonadism, male menopause or other underlying medical conditions.
You can decrease or increase testosterone production by treating the cause of the problem.
Get in touch with our team today if you have too little testosterone circulating in your blood and need an effective solution for this problem.
Evidence Based Research
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About the Author: Mike Kocsis
Mike Kocsis has an MBA with a focus on healthcare administration and is an entrepreneur and medical case manager for Balance My Hormones which offers medical services in the UK and Europe. Mike has over 20 years of experience in the healthcare sector, much of that working with people who have hormone imbalances. Mike has appeared on podcasts and radio and is an expert speaker on the subject of hormone imbalance. He specialises in Testosterone Replacement Therapy and Hormone Replacement Therapy (HRT) and has helped thousands of people suffering from hormone imbalances recover and regain control of their lives. You can follow him on LinkedIn and on the Balance My Hormones YouTube Channel.
Last update: September 10th, 2025
