From the Guidelines
Optimal testosterone levels vary by age in men, with total testosterone typically ranging from 300-1000 ng/dL for adult males, and treatment is typically considered when levels fall below 300 ng/dL with symptoms present, as suggested by the American College of Physicians 1.
Testosterone Levels by Age
- For men in their 20s and 30s, levels commonly fall between 600-900 ng/dL.
- In the 40s, a slight decline begins, with average levels between 500-800 ng/dL.
- By the 50s and 60s, levels often decrease to 400-700 ng/dL, and men over 70 may have levels between 300-600 ng/dL. These ranges represent general patterns, as testosterone naturally decreases by approximately 1-2% annually after age 30, as reported in a study published in the Annals of Internal Medicine 1.
Symptoms and Testing
If experiencing symptoms of low testosterone (fatigue, decreased libido, depression, reduced muscle mass), testing should include both total and free testosterone, preferably measured in the morning when levels peak.
Treatment Options
Testosterone replacement therapy options include:
- Injections (testosterone cypionate or enanthate, 50-200mg weekly or biweekly)
- Transdermal gels (AndroGel, Testim, 50-100mg daily)
- Patches (Androderm, 2-6mg daily)
- Pellets (implanted every 3-6 months) Treatment requires regular monitoring of testosterone levels, hematocrit, PSA, and liver function, as recommended by the American College of Physicians 1.
Important Considerations
The American College of Physicians suggests that clinicians discuss whether to initiate testosterone treatment in men with age-related low testosterone with sexual dysfunction who want to improve sexual function, and consider intramuscular rather than transdermal formulations when initiating testosterone treatment to improve sexual function in men with age-related low testosterone, as costs are considerably lower for the intramuscular formulation and clinical effectiveness and harms are similar 1.
From the Research
Optimal Testosterone Levels by Age
- The optimal testosterone levels for men vary by age, with older men generally having lower testosterone concentrations compared to younger men 2.
- There is no specific optimal testosterone level by age provided in the studies, but it is mentioned that testosterone levels below 300 ng/dl are considered hypogonadal 3.
- The normal range of testosterone concentration is not explicitly stated in the studies, but it is mentioned that the upper limit of lab normal range of testosterone concentration is used as a reference 3.
- Testosterone replacement therapy can be used to restore testosterone levels to the normal range in hypogonadal men, with benefits including improved sexual function, anaemia, and bone mineral density 2, 3, 4.
- The treatment of male hypogonadism can be individualized based on the patient's needs and medical history, with various treatment modalities available, including parenteral testosterone esters, oral testosterone undecanoate, and transdermal testosterone preparations 5, 4, 6.
Factors Influencing Testosterone Levels
- Age is a significant factor influencing testosterone levels, with older men having lower testosterone concentrations compared to younger men 2.
- Body mass index and medical comorbidities can also affect testosterone levels, with higher body mass index and certain medical conditions associated with lower testosterone levels 2.
- Testosterone levels can be influenced by various factors, including organic disease involving the hypothalamus, pituitary, or testes, as well as non-gonadal factors such as lifestyle and environment 2, 4.
Testosterone Replacement Therapy
- Testosterone replacement therapy can be used to treat hypogonadism in men, with various treatment modalities available, including parenteral testosterone esters, oral testosterone undecanoate, and transdermal testosterone preparations 3, 5, 6.
- The efficacy and safety of testosterone replacement therapy have been demonstrated in several studies, with benefits including improved sexual function, anaemia, and bone mineral density 2, 3, 4.
- The treatment of male hypogonadism should be individualized based on the patient's needs and medical history, with careful consideration of the potential benefits and risks of testosterone replacement therapy 4.