Anabolic steroids and testosterone

Anabolic steroids and testosterone

Testosterone, the so-called male hormone, is the most important androgen in the body. In men, Leydigin cells produce most of the testosterone in the testicles. Testosterone is also produced in the adrenal cortex and periphery by conversion of androstenedione. Women have much lower testosterone levels than men. However, it also has a significant effect on the female body. In women, testosterone is produced in the ovaries and in the adrenal cortex. Hormonal regulation of testosterone is maintained and controlled by the hypothalamic-pituitary-gonadal axis.

Androgens have androgenic, anabolic and psychological effects on the body. Androgenic effects include penis and prostate growth, hair growth in various areas, and baldness. Anabolic effects include laryngeal enlargement, vocal cord thickening, lipid changes, muscle growth, fat loss, sebaceous gland enlargement, and blood cell formation. The psychological effects of androgens include changes in libido, potency, sexual behavior and aggression.

Anabolic steroids are synthetic derivatives of testosterone. In medicine, anabolic steroids have been used to try and get the anabolic effects of testosterone without the virilizing side effects of androgens so children and women can use them too. However, the attempt failed. For this reason, the term “anabolic steroid” is misleading. It is more correct to use the term “anabolic androgenic steroids”.

Testosterone is a naturally occurring anabolic androgenic steroid in the body. Testosterone and other anabolic steroids have the same chemical structure. Attempts have been made to modify the structure of synthetic anabolic steroids by increasing the anabolic effect and reducing the androgenic effect. The ratio of anabolic and androgenic activity of testosterone is 1:1, and each has a strong influence. In other anabolic steroids, this relationship varies with the predominance of the anabolic effect. Moreover, the structure of anabolic steroids has been modified in order to adjust the route of administration, absorption, duration of exposure and aromatization of the substance. Therefore, anabolic steroids differ in their anabolic and androgenic relationship, route of administration (oral, intramuscular, dermal), absorption time, duration of action in the body, and aromatization to estrogen.

The history of testosterone use dates back to 1935, when testosterone was successfully isolated from bull testicles. It was discovered fairly quickly that oral testosterone is hepatotoxic and has a rapid half-life. After the synthesis of testosterone, the injectable propionate appeared on the market and later, in the 1950s, the long-acting enanthate. In the 1950s and 1960s the pharmaceutical industry became increasingly interested in new androgens, and by the end of the 1980s a large number of anabolic steroids had been developed, over a thousand.

Read also about what are anabolic steroids

Mechanism of influence

Testosterone and all anabolic steroids act through androgen receptors. Androgen receptors are located on the X chromosome of cells and are found throughout the body. In addition to muscles, androgen receptors affect the heart, immune system, and nervous system.

Testosterone and all anabolic steroids act through androgen receptors. Androgen receptors are located on the X chromosome of cells and are found throughout the body. In addition to muscles, androgen receptors affect the heart, immune system, and nervous system.

Mechanism of influence

The popularity of testosterone as a dopant is due to its strong effect on strength and muscle mass. Testosterone also affects lipolysis, i.e. the breakdown of fat cells. Short and long term use of anabolic steroids leads to increased cell growth due to increased protein synthesis. Testosterone-induced muscle cell growth is due to the activation of satellite cells and the growth of muscle cell nuclei.

The number of androgen receptors is limited and normal levels of testosterone are usually sufficient for them. Therefore, muscle growth is not necessarily due to an excess of anabolic steroids. Another mechanism explaining muscle growth could be the effect of anabolic steroids on cortisol. Cortisol is a catabolic hormone and anabolic steroids can reduce its effect. The inhibitory effect of anabolic steroids on the myostatin gene is also thought to be a muscle growth mechanism. Myostatin regulates muscle growth. Testosterone also increases the secretion of growth hormone and insulin-like growth factor.

Application in medicine

By classification, these substances are classified as prescription drugs, the use of which is permitted only for the treatment of diseases approved by drug control authorities. These diseases include, but are not limited to, testosterone deficiency syndrome (TSD), which develops due to dysfunction of the pituitary or testicles, various types of anemia, osteoporosis, and chronic diseases due to protein deficiency, and slow tissue healing. Testosterone is also used to treat symptoms of the male equivalent of menopause. The use of prescription testosterone has increased dramatically over the past decades, both in Finland and elsewhere.


Testosterone is used by injection as a mixture of various testosterone esters (eg, testosterone propionate, testosterone enanthate, testosterone phenylpropionate, testosterone isocaproate, testosterone decanoate, testosterone undecanoate, testosterone) or by mouth in the form of capsules containing testosterone undecanoate. Anabolic steroids are available in tablet and injectable form.

Side effects

Androgen receptors are present throughout the body, and therefore anabolic steroids affect the work of various internal organs. For this reason, there are a number of possible side effects. Some are mild and transient, and some are life-threatening. The risk of side effects increases with prolonged use of high doses.

Studying the side effects of anabolic androgenic steroids and obtaining scientific data is hampered by a number of factors. In some countries the use of anabolic steroids is prohibited, in which case a person is unlikely to report their use. Because the substance was purchased on the black market, the user may not know exactly what dose and what they are using. For ethical reasons, the side effects of high doses have not been studied in humans. In addition, substances intended for animals are misused and there are no data on human exposure to these substances. Therefore, research data is mostly speculative, often based on case studies and studies using medical doses.

According to a population study conducted in Finland, the risk of premature death in users of anabolic steroids and testosterone is 4.6 times higher than in the control group. In a similar Danish study, mortality among anabolic steroid users was three times higher over seven years than in the control group. Users were also much more likely to seek medical help.

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