Anabolic Steroids: Do They Cause Male Sterility?

By (gynecologist), (embryologist) and (invitra staff).
Last Update: 08/30/2023

Anabolic steroids are synthetic substances analogous to the hormone testosterone that today are used by athletes and young people, especially men, who look for hypermusculation.

The abuse of this practice, however, has harmful effects on the health of these people, as anabolic steroids interfere with hormonal regulation processes.

One of the negative effects of anabolic agents is the development of temporary sterility, as they block the production of sperm in the testicles.

What are anabolic steroids?

Steroids are a group of lipid molecules formed from cholesterol found naturally in the body. These include male and female sex hormones: androgens, estrogens, progesterone, etc.

Anabolic or anabolic steroids, on the other hand, are synthetic molecules derived from the hormone testosterone, the main androgen in men. These substances were originally created as therapeutic drugs and have two important effects on the body:

Anabolic action
increased muscle mass and weight due to increased protein synthesis.
Androgenic action
virilization or masculinization.

This is why these substances are also known as anabolic androgenic steroids (AAS).

Effects of steroids

Today, many of the men and women who consume anabolic steroids are athletes, bodybuilders and young people who go to the gym and seek to improve their performance and physical appearance.

That is, they seek the anabolic effect of steroids, namely to increase muscle tissue and decrease body fat.

However, excessive abuse of these substances without any medical control can have serious health consequences.

The hormone testosterone is responsible for regulating many processes in the human body, such as the growth of bone mass, the distribution of body fat, the formation of sperm, etc..

When testosterone is administered exogenously on a continuous basis, as would be the case with androgenic anabolic steroids, it causes significant deregulation in the body, such as those discussed below:

Male sterility

Sperm formation, a process known as spermatogenesis, is negatively regulated by the natural production of the hormone testosterone in the testicles.

This means that when there is high sperm production, testosterone sends a signal to the brain and blocks the synthesis of LH and FSH, hormones secreted by the pituitary gland and responsible for stimulating spermatogenesis.

In this way, all sperm and hormone production is regulated by the hypothalamus-hypophysis testicle axis.

However, by increasing the concentration of testosterone in the blood with injections of anabolic steroids, there is a continuous blockage of sperm production, leading to a situation of azoospermia.

The body cannot tell if the origin of the hormone testosterone is natural or artificial, so the formation of sperm in the testicles is interrupted and this results in endocrine sterility.

Besides, when the generation of sperm stops, the testicles become smaller, since most of the testicular volume corresponds to the testicular tubules where the spermatogenesis takes place.

This hormonal alteration can be reversed after eliminating the external supply of anabolic steroids, but a minimum of three months will be needed to restore testicular function.

For this reason, many elite bodybuilders and athletes decide to preserve their fertility by freezing their semen before starting anabolic steroid cycles, thus ensuring that they can be parents without any problems in the future.

Altered sexuality

Other unwanted effects of anabolic steroids are erectile dysfunction and decreased libido.

The explanation for these alterations has to do with the transport of testosterone in the body. Normally, testosterone can circulate in two different ways:

Bioavailable Testosterone
is testosterone that circulates freely in the blood or attached to protein albumin. It is usually between 40-65% of testosterone and is the part that the body can use and that produces sexual physiological responses.
Inactivated Testosterone
is testosterone that is linked to sex hormone binding globulin (SHBG) and is usually between 35-60%. This testosterone cannot be used by the body.

What happens with the consumption of anabolic steroids is that the production of SHBG is increased. This results in more inactivated and less bioavailable testosterone, leading to sexual dysfunction.


Anabolic androgenic steroids may also cause the appearance of female sexual characteristics in males.

This is due to the increase in estrogen (female hormones) caused by an excess of androgens in the body, as both come from the same metabolic pathway.

The most common symptom is gynecomastia, the growth and development of the mammary glands in men.

Other alterations

Apart from what has been said so far, AAS can cause other health problems for people who abuse them:

  • Cardiovascular diseases
  • Hypertension
  • Increased cholesterol
  • Liver and kidney diseases
  • Tumors
  • Psychiatric problems: aggressiveness, irritability, depression, delusions, etc.

It is important to note that all side effects of anabolic steroids can be both reversible and irreversible.

For all these reasons, information and prevention about anabolic agents is fundamental in today's society, as more and more people are consuming these substances and are at risk of suffering all the problems that this entails.

FAQs from users

Is female infertility caused by anabolic steroids reversible?

By Laura de la Fuente Bitane M.D. (gynecologist).

Sterility caused by anabolic steroids in women is specifically due to the effect of androgen on the ovary causing anovulation and a picture similar to polycystic ovary syndrome. Its effect can be reversed after a while. Let us remember that cases of gestation have been described even in women who had been treated with male hormones to change sex.
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What is an androgenic anabolic steroid cycle?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

A cycle of anabolic agents is a specific dosed administration program followed by people who consume these substances, especially athletes and bodybuilders.

It is based on the strategic consumption of anabolic steroids, so that the athlete can get the maximum performance, but reducing the side effects and economic cost of all anabolic to use.

What happens if I don't regain fertility after stopping anabolic agents?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

In 60% of cases, males spontaneously regain testicular function about 6 months after stopping androgenic anabolic steroids.

If this is not the case, it would be necessary to see a specialist who could prescribe a treatment with FSH and LH to stimulate the testicle.

What are natural anabolic agents?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Unlike androgenic anabolic steroids, natural anabolics are substances that are often used as nutritional supplements with the aim of stimulating the endogenous production of hormones that promote muscle growth.

Some of the most outstanding nutrients such as natural anabolics are creatine, coenzyme B12, proteins, glutamine, leucine, etc..

It should be noted that, despite being more harmless, these food supplements should also be consumed under the control of a doctor or specialist nutritionist.

Suggested for you

There are other alterations or pathologies that cause male sterility due to a hormonal irregularity. If you want more information related to this topic, we recommend you enter the following article: Male infertility due to pretesticular causes.

Apart from testosterone, there are other hormones involved in male fertility. If you want to get more the details about this, you can read more here: What male hormones take part in reproduction?

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Nick A. Evans. Current Concepts in Anabolic-Androgenic Steroids. The American Journal of Sports Medicine 2004; 32 (2): 534 - 542 (Ver)

Nasrollah T. Shahidi. A review of the chemistry, biological action, and clinical applications of anabolic-androgenic steroids. Clinical Therapeutics 2001; 23 (9): 1355-1390 (Ver)

World Health Organization (WHO). Contraceptive efficacy of testosterone-induced azoospermia in normal men. Lancet 1990; 336: 955-999 (Ver)

FAQs from users: 'Is female infertility caused by anabolic steroids reversible?', 'What is an androgenic anabolic steroid cycle?', 'What happens if I don't regain fertility after stopping anabolic agents?' and 'What are natural anabolic agents?'.

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Authors and contributors

 Laura de la Fuente Bitane
Laura de la Fuente Bitane
Degree in Medicine and Surgery at the Autonomous University of Madrid, specializing in Obstetrics and Gynecology. She has a long experience as a specialist gynecologist in Assisted Reproduction and is an Associate Professor at the Complutense University of Madrid. More information about Laura de la Fuente Bitane
Licence: 28-45574
 Zaira Salvador
Zaira Salvador
B.Sc., M.Sc.
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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