This is a controversial account of why, because of the barriers to testosterone action in the body, men can have normal levels of testosterone but still have life-, love-, and health-wrecking symptoms of testosterone deficiency which need treatment. The deficiency is increasingly being linked to common and serious medical conditions such as obesity, diabetes, heart and circulatory disorders, and even Alzheimer's disease. This has clearly been shown by the author's pioneering research publications as well as those of other colleagues and researchers worldwide. However, in the majority of cases, they are often denied this because of the lack of understanding of the medical profession and other authorities regulating the treatment. This is a wake-up call to both doctors and patients alike to treat the symptoms of testosterone deficiency and related conditions with what the author argues is the most effective, safest, and economic form of preventive medicine of the twenty-first century.