Background - In the context of hypogonadism, androgen supplementation is clearly beneficial, particularly in younger males. The benefits of therapy in men with milder degrees of hypogonadism, and elderly males with testosterone deficiency, are less clear-cut. Several options are available for androgen replacement in adult men. Oral testosterone, intramuscular injections, subcutaneous implants and transdermal therapy have all been used. Each mode of delivery has advantages and drawbacks. Several alkylated derivatives of T are available for oral or sublingual use, including methyl testosterone and fluoxymesterone. However, they are not recommended for use as replacement therapy because of their associated adverse effects.