Testosterone is the primary male sex hormone that is responsible for physical changes and development in the male body. Testosterone is very much vital for the reproduction system.
The effect of the testosterone hormone becomes more prominent in puberty.
In this period the production of testosterone is high and the physical changes like deepening of the voice, hair growth on the body and facial areas, development of sexual organs, increased sexual desire, and many more.
All these effects are the Androgenic effects of testosterone. If the testosterone production in our body is not significant many other hormones and systems will not work properly.
Testosterone is the only reason why males are able to build more muscle mass and have more bone density than women.
In women the dominating sex hormone is Estrogen but women also produce small amount of testosterone in their ovaries and adrenal glands for overall body growth.
Estrogen is the main reason why women hold more body fat than muscle tissue and with aging due to low testosterone bone gets weaker in women. This is the reason why women need to take more care of their bodies in older age.
Biological Effects of Testosterone
Testosterone mainly has Androgenic and Anabolic properties in our body.
1. Anabolic Properties – This property of testosterone helps to promote muscle growth, protein synthesis, increase in strength, develop bone density and maturation.
2. Androgenic Property – This property of testosterone helps to promote secondary sexual characteristics in men such as hair growth, development of sexual organs such as Penis, Deepening of voice, increase in libido and increase in oil production from Sebaceous glands.
The effect of testosterone in our body differs with age in every individual. Testosterone level drops as we age. So every year there is a slight drop in testosterone.
At puberty testosterone level is highest and after 30 years old testosterone level will drop significantly.
Effects of Testosterone in our Body
- In our early stages of life, testosterone helps in brain development.
- In the male body sperm production is a never-ending job that is done by Testosterone.
- Significant levels of testosterone are important for heart health.
- Testosterone is the reason for Aggression.
- Testosterone promotes Protein synthesis, Fat loss, and muscle growth.
- Testosterone develops our immune system.
- Testosterone promotes the production of red blood cells.
- Testosterone is essential for the central nervous system, Endocrine system, and Reproductive system.
Testosterone Production and DHT Conversion
Testosterone production is the crucial part and you need to understand the production of testosterone clearly in order to understand the whole article.
In our body testosterone is produced by the HPT axis as shown in the above image.
When there is a low level of testosterone in our body Hypothalamus gland releases the Gonadotropin-releasing hormone which is transported by the hypophyseal portal system which acts on the receptors (GnRHR) of the Pituitary gland.
Signaling from GnRHR leads to the secretion of LH (Luteinizing Hormone) and FSH (Follicle Stimulating Hormone). LH hormone stimulates the Leydig cells in the testes to produce testosterone.
The FSH hormone is used to stimulate testicular growth and enhance the production of an androgen binding protein by the Sertoli cells which are necessary for maturing the Sperm cells.
When there is enough testosterone production in our body, the testes signal Hypothalamus and Pituitary gland to stop producing GnRH, LH, and FSH which is known as a Negative Feedback Loop.
The amount of testosterone production by Leydig cells is fully dependent upon Hypothalamus and the Pituitary gland.
Note - Hypothalamus sends signals to the pituitary to produce LH and FSH which stimulate the Leydig cells in Testes and result in the Production of testosterone
DHT means Dihydrotestosterone which is the byproduct of testosterone in our body. DHT is an endogenous androgen sex hormone that is responsible for the secondary sexual character in males such as hair growth and developing sexual organs and prostate gland.
DHT or Dihydrotestosterone is a powerful steroid hormone naturally found in the human body. It is 4 to 5 times stronger than testosterone.
Testosterone in our body converts to DHT when it comes in contact with 5-alpha reductase enzymes. 5-alpha reductase catalyzes the testosterone conversion to DHT. This enzyme removes the C4-5 double-bound of testosterone and adds two hydrogen atoms and so it is named Dihydrotestosterone.
With the change in the chemical structure, it can bind with androgen receptors more easily and rapidly hence making it more powerful than Testosterone.
The 5-alpha reductase enzyme is present in high amounts in the cells of the Prostate gland, skin, scalp, Seminal vesicles, Epididymis, brain, and liver. Here the enzyme is present in higher amounts because the need for androgenic properties in this area is higher. Here in these areas very small amounts of testosterone will be converted to the powerful steroid hormone, Dihydrotestosterone.
Estrogen is the principal sex hormone in the female body and responsible for female physical structure and reproduction. Estrogen is the main hormone in the female produced by the ovaries that makes a girl into a woman.
Men also have estrogen in their body but in very small amounts which are produced by the aromatase tissue present in the different body parts. Testosterone is the primary reason for the production of Estrogen through the process of Aromatization.
What is Aromatization?
Aromatization is the natural process performed by our body to convert excess testosterone into Estrogen.
This process is performed by our body to maintain the hormonal balance which is known as Homeostasis.
This process is named as Aromatization because it involves the naturally occurring enzyme called aromatase.
Aromatization mainly occurs in male body but it also occurs in the female body when there is excess testosterone.
What is Aromatase?
Aromatase is a naturally occurring enzyme located in multiple tissues in the body like the brain, muscles, and testicles. In women, it is also located in the ovaries, placenta, and lining of the uterus.
Aromatase enzymes convert testosterone into estrogen in our bodies. This enzyme also controls the regulation of the cortisol hormone to maintain our immune system.
Why does Aromatization occur?
Aromatization occurs in our body to maintain the balance between two hormones Testosterone and Estrogen ratio which is known as Homeostasis.
Homeostasis is the equilibrium function of the body that keeps everything in normal levels to keep our body healthy.
A healthy person produces 250 to 900 ng/dl daily, this amount of testosterone will naturally come along with a small amount of estrogen production to maintain the optimal testosterone to estrogen ratio.
Aromatization actually occurs when there is a large fluctuation in testosterone level caused by taking some kind of performance-enhancing drugs.
What causes the increase in Aromatization?
Aromatization occurs for both increase in testosterone level and decrease in testosterone level.
That means if your body is producing more testosterone chances are there for aromatization (Especially when using performance-enhancing drugs) and also when your body is not producing much testosterone then also chances are there too ( Especially in old age).
Apart from all these excessive alcohol consumption, Obesity, Poor nutrition are the common causes that can increase Aromatization.
Side effects of high level testosterone :-
- Acne and Pimples ( due to overactive sebaceous gland)
- Fluctuation in blood pressure (high or low blood pressure)
- Heart Diseases (including heart attack and stroke)
- Erectile Dysfunction
- Cholesterol Problems ( increase in bad cholesterol)
- Polycythemia Vera, which is caused by a high level of red blood in our body
- Irregular periods in women
- Problem with infertility in women
Side Effects of high level Estrogen:-
- Erectile Dysfunction in men
- Low sex drive in women
- Sleeping Problem
- Weight gain ( water mass)
- Gynecomastia in men
- Decrease in Sperm count in men
Side effects of high level DHT:-
- Hair fall on the scalp
- Increase hair growth in body and facial areas
- Excessive increase in Libido
- ACNE problem