Most men will be given one of three types of common therapy but each type, although unique in application form will carry with it the same hormone, testosterone. The most common types of testosterone replacement therapy include either injectable or transdermal application. Injectable testosterone will prove to be the most potent, effective and efficient of all, while transdermal application will work it will not do so at the same level. There are two common forms of transdermal applications, gels known as AndroGel and patches known as AndroDerm . All three forms of testosterone replacement therapy will increase testosterone levels but some men will find only the injectable forms to be powerful enough to bring their levels to where they truly need to be. In the end it is impossible to predict, transdermal application may be all you ever need but you will find there is often a phase of trial and error to determine what is best for you.