INTRODUCTION Testosterone treatment has evolved rapidly over the past 25 years as new, more effective and convenient methods have become available. This study reports experience with seven different methods, introduced on the market in the UK. AIM To establish the symptom response when testosterone treatment was initiated on the basis of clinical features and symptoms of androgen deficiency, and the resulting endocrine, biochemical and physiological responses. METHODS Of 2693 patients attending the 3 Men's Health Centers - The UK Androgen Study (UKAS), 2247 were treated. Treatments included pellet implants, oral testosterone undecanoate (Testocaps), mesterolone (Proviron), testosterone gel (Testogel), testosterone scrotal cream (Andromen) and scrotal gel (Tostran). RESULTS There was no correlation between initial testosterone level, initial symptom score or the success of treatment as defined by adequate resolution of symptoms. Despite the diverse endocrine patterns produced, the testosterone preparations appear equally safe over prolonged periods, with either no change or improvement of cardiovascular risk factors, especially in lowering cholesterol and diastolic blood pressure. CONCLUSIONS It is suggested that because of excessive reliance on laboratory measures of androgens and undue safety concerns, many men who could benefit from symptom relief, improvement in related clinical conditions and given preventive medical benefits remain untreated.