Testosterone

Testosterone is often thought of as the primary male sex hormone, but it is genuinely important for everyone. Produced mainly in the testes in men and in smaller amounts by the ovaries and adrenal glands in women, testosterone influences a remarkably wide range of bodily functions, from muscle strength and bone density to mood, energy levels, and libido. Maintaining healthy testosterone levels supports your overall vitality and sense of wellbeing, regardless of your sex. Imagine testosterone as the fuel that keeps several of your body's engines running smoothly, your muscles use it to repair and grow after exercise, your bones rely on it to stay strong and dense, and your brain depends on it for motivation and mental clarity. In men, testosterone also drives the development of male physical characteristics during puberty and continues to support reproductive health throughout life. In women, even though levels are much lower, testosterone contributes to energy, sexual desire, and muscle tone. Your body carefully regulates testosterone through a feedback loop involving the pituitary gland and the hypothalamus, adjusting production to keep levels within an optimal range.

Several lifestyle and biological factors can affect your testosterone levels. In men, levels naturally decline gradually from around the age of thirty, typically by about one to two per cent per year. Poor sleep, chronic stress, excess body fat, a sedentary lifestyle, and excessive alcohol intake can all contribute to lower levels.

For men, the British Society for Sexual Medicine (BSSM) provides simple guides for interpreting total testosterone. A level above 12 nmol/L is generally considered sufficient. A level between 8 and 12 nmol/L sits in a borderline range, where free testosterone, symptoms, and other markers help guide interpretation. A level below 8 nmol/L suggests Testosterone Deficiency that usually warrants clinical assessment. For men on testosterone therapy, BSSM additionally targets a 15 to 30 nmol/L treatment band, with values above 30 nmol/L sitting above this band and warranting a discussion with your clinician about dose timing or repeat measurement. Morning samples (8-11 am) and a confirmatory repeat are typically used before treatment is considered. For women, reference ranges are much lower and are interpreted differently depending on age and life stage. These thresholds are guides, not diagnoses, and your GP will weigh them alongside your symptoms, SHBG, free testosterone, and overall clinical picture.

In women, testosterone may fluctuate with the menstrual cycle and tends to decrease after the menopause. Certain medications, including hormonal contraceptives and corticosteroids, can also have an effect. If your testosterone result is outside the expected range, your GP can assess it alongside other markers such as SHBG and free testosterone to build a complete picture and discuss any next steps with you.