What is Testosterone
Testosterone is a critical sex hormone and anabolic steroid in males. It has an essential role in the development of male reproductive tissues like the testes and prostate, as well as in promoting secondary sexual characteristics, such as increased muscle and bone mass and the growth of body hair. Both sexes require testosterone for overall health and well-being, including moods, behavior, and preventing osteoporosis. Low levels of testosterone in men can cause abnormalities, such as frailty and bone loss.
Testosterone is a steroid from the androstane class, containing a ketone and a hydroxyl group at positions three and seventeen, respectively. It is synthesized from cholesterol and converted into inactive metabolites in the liver. Testosterone’s effects occur by binding to and activating the androgen receptor. In humans and most other vertebrates, the testicles of males and, to a lesser extent, the ovaries of females primarily secrete testosterone. On average, adult males have testosterone levels that are seven to eight times greater than adult females, and the daily production of testosterone is approximately 20 times greater in men. Females are also more sensitive to the hormone.
Apart from its natural role, testosterone is used medically to treat hypogonadism in men and breast cancer in women. It is sometimes used in older men to counteract age-related testosterone deficiency. Illicit use of testosterone is also seen to enhance physical performance, particularly in athletes, and is prohibited by the World Anti-Doping Agency, which lists it as an S1 Anabolic agent substance “prohibited at all times.”
Biological effects of Testosterone
Testosterone is a hormone that plays a vital role in the development and maintenance of male sexual characteristics. In addition to its role in sexual development, testosterone also has many other biological effects throughout the lifespan. In this article, we will explore the biological effects of testosterone at various stages of life, as well as its effects on aggression, the brain, and the immune system.
Testosterone levels are relatively high at birth and continue to rise during the first few months of life. This surge in testosterone is important for the development of male genitalia and reproductive organs. However, it is also thought to have a role in the development of social behavior and cognitive abilities in both males and females.
After the first few months of life, testosterone levels in both males and females drop to low levels. During this time, testosterone is thought to play a role in the development of the brain and nervous system. Some studies have suggested that higher levels of testosterone during infancy may be associated with better cognitive and language development in both boys and girls.
Testosterone levels remain low throughout childhood until the onset of puberty. During this time, testosterone is important for the development of muscle and bone mass in both males and females.
During puberty, testosterone levels rise dramatically in males, leading to the development of secondary sexual characteristics such as facial hair, a deepening voice, and increased muscle mass. In females, testosterone levels also rise, but to a lesser extent. Testosterone plays an important role in the development of sexual desire and the regulation of the menstrual cycle in females.
Testosterone levels continue to play a role in sexual function and fertility in adults. In males, testosterone is responsible for the production of sperm and the maintenance of sexual function. In females, testosterone is important for sexual desire and the maintenance of bone and muscle mass.
Aggression and criminality
Testosterone has long been associated with aggression and criminality, particularly in males. While the relationship between testosterone and aggression is complex and not fully understood, some studies have suggested that higher levels of testosterone may be associated with increased aggression in both males and females.
Testosterone and Brain
Testosterone has been shown to have a variety of effects on the brain and nervous system. In males, testosterone is important for the development and maintenance of spatial and verbal memory, as well as overall cognitive function. In females, testosterone is important for mood regulation and cognitive function.
Testosterone and Immune system
Testosterone has been shown to have anti-inflammatory effects in both males and females. Studies have suggested that higher levels of testosterone may be associated with lower levels of inflammation and a decreased risk of some chronic diseases.
Testosterone plays a critical role in the development and maintenance of many biological systems throughout the lifespan. While its effects on aggression and criminality are complex and not fully understood, testosterone has been shown to have a variety of positive effects on the brain, immune system, and overall health.
History of Testosterone
The history of testosterone is rich and fascinating. Early work on castration and testicular transplantation in fowl by Arnold Adolph Berthold in the mid-1800s linked testicular action to circulating blood fractions, which we now know to be a family of androgenic hormones. However, it wasn’t until the late 1800s and early 1900s that research on the action of testosterone began to receive attention.
In 1889, the Harvard professor Charles-Édouard Brown-Séquard self-injected a “rejuvenating elixir” consisting of an extract of dog and guinea pig testicle and reported in The Lancet that his vigor and feeling of well-being were markedly restored. However, his hopes for the compound were dashed after suffering ridicule from his colleagues.
It wasn’t until the 1930s that three European pharmaceutical giants – Schering, Organon, and Ciba – began full-scale steroid research and development programs. The Organon group in the Netherlands was the first to isolate testosterone and identify it in a May 1935 paper “On Crystalline Male Hormone from Testicles (Testosterone)”. The chemical synthesis of testosterone from cholesterol was achieved in August of that year by Adolf Butenandt and Hanisch, and a week later, the Ciba group in Zurich, Leopold Ruzicka and A. Wettstein, published their synthesis of testosterone.
The partial synthesis of testosterone esters in the 1930s permitted the characterization of the hormone’s effects. Researchers were able to demonstrate both anabolic and androgenic effects of testosterone propionate in eunuchoidal men, boys, and women. The period of the early 1930s to the 1950s has been called “The Golden Age of Steroid Chemistry,” and work during this period progressed quickly.
The history of testosterone is a testament to the perseverance and ingenuity of scientists throughout history. From Berthold’s early work on castration to the discovery and synthesis of testosterone in the 1930s, our understanding of this hormone has come a long way. Today, testosterone plays a critical role in the health and well-being of individuals, and its importance is only continuing to grow.
Testosterone is involved in various physiological functions such as bone and muscle mass maintenance, regulation of sexual desire, and cognitive function. However, some individuals may experience low levels of testosterone, which can lead to symptoms such as decreased libido, erectile dysfunction, decreased muscle mass, and decreased bone density. In such cases, testosterone medication can be prescribed.
Testosterone medication can be administered in different forms, such as injections, gels, patches, and pellets. The choice of the delivery method depends on the individual’s preference and the physician’s recommendation. Testosterone therapy can be beneficial for individuals with hypogonadism, a condition in which the body produces low levels of testosterone. It can also be prescribed for individuals with gender dysphoria who wish to undergo hormone therapy as part of their transition.
While testosterone medication can be beneficial, it can also have side effects. The most common side effects include acne, oily skin, increased hair growth, and breast enlargement in men. It can also increase the risk of developing prostate cancer, especially in men with a history of prostate cancer or other prostate-related conditions. Additionally, testosterone therapy can increase the risk of blood clots and cardiovascular events, especially in older men.
Therefore, before initiating testosterone therapy, the physician should carefully evaluate the individual’s medical history, physical exam, and laboratory tests to determine if the benefits outweigh the risks. Regular monitoring of the individual’s testosterone levels, prostate-specific antigen levels, and cardiovascular risk factors is also necessary to ensure the safety and efficacy of testosterone therapy.
In conclusion, testosterone medication can be beneficial for individuals with hypogonadism or gender dysphoria who wish to undergo hormone therapy. However, it should only be prescribed after a thorough evaluation of the individual’s medical history and laboratory tests. The physician should also carefully monitor the individual’s testosterone levels and potential side effects to ensure the safety and efficacy of testosterone therapy.