In males, the widespread prevalence of both obesity-related metabolic syndrome (MetS) and testosterone deficiency (TD) is further exacerbating the socio-economic and health burdens already elicited by the rapidly ageing global population. The strong reciprocal relationship between the MetS and TD in males often results in their shared pathologies presenting together in the clinical setting. Clinical and epidemiological studies have provided convincing evidence that the MetS and TD are highly comorbid [1, 2] and share mutual abnormalities, including visceral obesity, dyslipidaemia and insulin resistance. One or more of these changes associated with the MetS and TD contribute to life-threatening conditions such as cardiovascular disease and increased osteoporotic bone fragility, particularly in the ageing male. Due to limitations of traditional androgen replacement therapy with testosterone (TEST), which is readily converted to active metabolites by enzymes, the therapeutic potential of trenbolone (TREN), a selective androgen receptor modulator (SARM), remains an attractive alternative to TEST. However, TREN’s efficacy has not been investigated in appropriate models representative of obese and TEST-deficient males, especially within the context of cardiometabolic disease and obesity-related osteoporosis/bone strength.