What is Testosterone?
Testosterone is a type of sex hormone primarily responsible for the development of male characteristics. It’s present in both sexes, but concentrations are naturally much higher (around 10x as higher) in men which is why it’s termed as the male hormone.
In men, testosterone is mainly produced in the testes and in small quantities by the adrenal glands. Two regions of the brain — the hypothalamus and pituitary gland — work a bit like a thermostat to make sure testosterone levels are tightly controlled to stay within a normal range.
Testosterone is responsible for changes during puberty such as voice deepening, body hair growth, and growth spurts. In adults, it plays an important role in regulating:
- Sex drive (libido)
- Sperm production
- Muscle growth and development
- Fat distribution
- Bone mass
- Red blood cell production
- Mood and energy levels
Before understanding what normal testosterone levels look like, first, it’s important to appreciate the difference between total and free testosterone measurements.
Total vs Free Testosterone
Testosterone is secreted directly into the bloodstream from the testes where most of it binds to two proteins: sex hormone-binding globulin (SHBG) and albumin.
The remaining testosterone that isn’t attached to proteins is known as free testosterone (FT), the more active form of the hormone. Free testosterone enters the cells and binds to receptors where it triggers changes in growth and metabolism.
Total testosterone (TT) is a measure of how much testosterone there is in the blood — both free and bound. Therefore, TT will always be higher than FT.
Generally, if a testosterone deficiency is suspected, a TT measurement is taken first. If this is at the low end of the normal range, an FT measurement may be taken too. That’s because it’s possible to have a normal TT with a low FT level.
Serum Testosterone
Serum testosterone refers to the total amount of testosterone present in the blood, which includes both free testosterone (not attached to proteins) and testosterone that is bound to proteins. It is commonly measured through a blood test to assess hormone levels and diagnose various health conditions related to testosterone imbalance.
DHT (Dihydrotestosterone)
DHT is one of the most potent androgens in the human body and plays a crucial role in male characteristic development. It is a derivative of testosterone, created when enzyme-5-alpha reductase converts testosterone into DHT. It contributes to:
- Male sexual development
- Facial & body hair growth
- Prostate health
- Muscle density and strength
- Libido & sexual function
Unlike testosterone, which can be converted into oestrogen (through aromatisation) DHT cannot be aromatised. Meaning it is purely androgenic, however the following negatives have been observed
- Hair loss
- Prostate enlargement
- Acne & oily skin
"Normal" Testosterone Levels
According to the American Urological Association (AUA), healthy male testosterone levels range between 450 and 600 ng/dL, and low testosterone is below 300 ng/dL. However, we have seen average levels drop significantly throughout the generations, or 'The Generational Decline' as we call it, which can be attributed to by a more toxic environment, sedentary lifestyle as well as poor diets.
Effects of Low Testosterone Levels
Low levels of testosterone can produce a variety of symptoms in men including:
- Decreased sex drive
- Less energy
- Weight gain
- Feelings of depression
- Moodiness
- Low self-esteem
- Less body hair
- Thinner bones
Conclusion
Testosterone is a cornerstone hormone in the male body, orchestrating a wide array of physiological and psychological functions that are essential for overall health and well-being. From driving the physical transformations of puberty to sustaining sexual health, muscle strength, bone density, and emotional stability in adulthood, testosterone is a critical measure of male vitality. Its influence extends beyond physical attributes, shaping confidence, energy levels, and mental clarity.
Maintaining balanced testosterone levels is vital, as imbalances, whether low or excessively high, can lead to significant health challenges, including reduced libido, fatigue, mood disorders, or even long-term risks like osteoporosis or cardiovascular issues. Regular monitoring through blood tests, coupled with a healthy lifestyle, can help optimise testosterone levels and support long-term wellness. For those experiencing symptoms of deficiency or seeking to understand their hormonal health, consulting a healthcare professional is key to tailored solutions, whether through lifestyle adjustments, medical interventions, or hormone therapy. Ultimately, testosterone is not just a marker of masculinity but a fundamental driver of holistic health, underscoring its importance in both medical and personal contexts.