From the Research
Testosterone Levels in Young Men
- A testosterone level of 412 ng/dL in a 34-year-old male is within the normal range for his age group, according to a study published in 2022 1.
- The study found that the age-specific middle tertile levels for men aged 30-34 years old were 359-498 ng/dL, and the age-specific cutoff for low testosterone levels was 359 ng/dL.
Diagnosis of Testosterone Deficiency
- The diagnosis of testosterone deficiency is typically based on consistent signs and symptoms of androgen deficiency and unequivocally low serum testosterone (below 300 ng/dL) 2.
- However, a study published in 2005 suggests that total testosterone levels <200 ng/dL indicate hypogonadism, and levels between 200 and 400 ng/dL require further evaluation, including measurement of free testosterone 3.
Variability in Laboratory Reference Values
- Laboratory reference values for testosterone vary widely, with different assays and reference ranges used by different laboratories 4.
- A study published in 2012 found that total testosterone measurement has low specificity for the biochemical diagnosis of hypogonadism, except when levels are less than 150 ng/dL 5.
Clinical Significance
- A testosterone level of 412 ng/dL in a 34-year-old male is not indicative of hypogonadism, based on the available evidence 1, 3, 5.
- However, it is essential to consider the individual's symptoms and medical history, as well as the laboratory's reference values, when interpreting testosterone levels 3, 2.