Testosterone replacement therapy has been used since the 1940s. Injections, usually given every few weeks, are one of the oldest ways to increase testosterone. Gels are used widely in the . They are applied daily to the shoulder, abdomen, or upper arm. The general goal of treatment is to raise the blood testosterone level only into the mid-normal range -- about 400-700 ng/dL. Other methods include patches, oral adhesive tablets and TESTOPEL (testosterone pellets), which is a pellet that is injected subcutaneously and can last 3-6 months.