Diagnostic tools like ANDROTEST have estimated a disease incidence of 10%–40% in men aged over 45 years and suggest that up to 60 million men in the United States, Europe and Japan suffer

binding globulin SHBG and concurrent disease states, an individual’s total circulating T may fall below the eugonadal range despite being asymptomatic. Decreased sex hormone binding globulin resulting from any number of separate pathologies may allow eugonadal levels of free T (unbound) despite hypogonadal levels of total T. Likewise, elevated levels of sex hormone binding globulin might result in hypogonadal symptoms, due to reduced levels of free T, despite eugonadal levels of total T. For these reasons it has been suggested that free T levels, along with associated symptoms of hypogonadism, be used in the positive diagnoses of LOH.3,8 Though it is accepted that eugonadal levels of total T are variable and patient specific, the range of approximately 300–1000 ng dl−1 (10.4–34.7 nmol l−1) has been adopted and is used to gauge the success of TRT. When T therapy is indicated, minimally therapeutic T levels are desired and the upper end of the eugonadal range for young men (1000 ng dl−1) is generally avoided as the risks associated with T therapy are thought to increase with the levels of exogenous T administered.9 Currently available T product labeling suggests monitoring serum T and dose adjustments to maintain appropriate T levels. T therapy has well‐established beneficial effects on body composition, including increases in lean body mass and decreases in fat mass.10,11 These effects are rapid (apparent after as little as 3 months of therapy) and durable (maintained after 3 years).12,13 Increases in muscle strength are less consistently reported due to training effects and technical challenges in measuring maximal muscle strength. 14 However, durable muscle strength benefits are reported in placebo controlled TRT trials performed in a hypogonadal population.15 Improvements in lumbar spine and hip BMD require extended treatment, but have been reported following T therapy in a placebo controlled setting.16 Rapid improvements in sexual function are a hallmark of T administration INTRODUCTION As the population ages, longitudinal and cross‐sectional studies have shown that a significant portion of men over the age of 60 have serum testosterone (T) levels below the lower limits of those seen in healthy younger men (20–30 years).1,2 Late onset hypogonadism (LOH) encompasses a broad list of signs and symptoms including sexual dysfunction, fatigue and reduced lean body mass and bone mineral density (BMD) that are associated with low T and are what typically drives the patient to seek medical attention.3 Due to the often varied intensity of these symptoms and their association with non‐pathological general ageing processes, a significant effort has been made to clearly define LOH and thus patients who might benefit from therapy.4 Despite such efforts, LOH prevalence remains controversial as does the treatment of men who do not display overt hypothalamic‐pituitary‐gonadal pathology where the risk benefit profile of androgen supplementation is more clearly established.5 Diagnostic tools like ANDROTEST have estimated a disease incidence of 10%–40% in men aged over 45 years and suggest that up to 60 million men in the United States, Europe and Japan suffer from LOH.3,6,7 Conversely, more stringent criteria have placed LOH rates at as little as 2.1% in similarly aged men.8 Regardless of the diagnostic criteria employed, the current gold standard for the treatment of hypogonadism in older men is T therapy.3