Testosterone is the best-known androgen (i.e., male sex hormone). It is secreted by the testicles and is responsible for the development and maintenance of secondary male characteristics (e.g., increased body and facial hair, enlarged larynx, deep voice, muscularity). Low testosterone (i.e., hypogonadism) results from the failure of the testicles (i.e., the gonads) to produce normal levels of testosterone due to a problem within the hypothalamic-pituitary-testicular (HPT) axis.[1]
What is low testosterone?
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•Last Updated: May 16, 2025
Low testosterone, or hypogonadism, occurs when the testicles fail to produce normal levels of testosterone due to issues within the hypothalamic-pituitary-testicular axis. Testosterone is the primary male sex hormone that is responsible for developing and maintaining secondary male characteristics.