Testosterone is widely recognized for its role in regulating male sexual function, but this hormone also plays a vital part in maintaining muscle and bone mass, energy levels, blood production, and fat distribution. Testosterone levels typically begin to decrease gradually from around 30-35 years of age. However, low testosterone is not solely linked to aging; it can also stem from underlying health conditions such as obesity, type two diabetes, cardiovascular-metabolic diseases, and various other chronic illnesses.

Master, Doctor Doan Vinh Binh, from the Medical Information Center at Tam Anh General Hospital, TP HCM, outlines the symptoms that may signal a decline in male testosterone.

**Reduced libido**

Sexual dysfunction is the most clearly associated group of signs with low testosterone. Men may experience a decrease in libido, less frequent morning erections, and difficulty achieving or maintaining sexual performance. However, erectile dysfunction does not always mean low testosterone. Cardiovascular disease, diabetes, obesity, neurological conditions, certain medications, and psychological factors can also contribute to this issue.

A doctor at Tam Anh General Hospital advises a patient. Photo: Hospital provided

A doctor at Tam Anh General Hospital advises a patient. Photo: Hospital provided

**Muscle loss and increased belly fat**

Testosterone is integral to maintaining muscle mass and strength. When hormone levels drop, muscle mass decreases, and muscle strength weakens. Simultaneously, fat accumulation increases, particularly in the abdominal region.

Doctor Binh notes that age is not the sole factor. Obesity and dyslipidemia can accelerate the aging process of Leydig cells—cells responsible for testosterone production in the testes—through chronic inflammation, oxidative stress, and impaired cellular energy function.

**Fatigue, low energy, and mood changes**

With low testosterone levels, men may feel fatigued, experience reduced energy, struggle with concentration, lack motivation, or notice mood swings such as increased irritability or sadness. These symptoms are often non-specific and can arise from other conditions like sleep deprivation, prolonged stress, depression, obesity, or chronic illness.

An analysis from the European Male Aging Study (EMAS), conducted on nearly 2,400 men aged 40-79 across 8 European centers from 2003-2005, recorded an average total testosterone decline of approximately 0,1 nmol/L each year over a follow-up period of about 4,4 years. The magnitude of change was not substantial and varied among individuals, indicating that age alone cannot precisely predict a person's testosterone levels.

Doctor Binh states that increasing age does not automatically equate to testosterone decline. This hormone usually decreases gradually, with symptoms often being atypical and prolonged. When experiencing a combination of reduced libido, fewer morning erections, difficulty maintaining muscle mass, increased belly fat, fatigue, or mood changes, men should seek medical consultation to determine the underlying cause. Certain extracts, such as eurycoma longifolia, French maritime pine bark extract, and oyster extract, may be used to support male physiological function and health.

Dinh Dieu