Testosterone levels increase within hours and by the second or third day of treatment, it plateaus to the level at which it will stay as long as treatment continues, said Dr. Ronald S. Swerdloff, lead investigator of the study that led to the FDA approval. The testosterone is readily absorbed into the skin, which serves as a reservoir for the sustained release of the hormone into the bloodstream. This gel is an alternative to traditional hormone treatments, injections and patches. Injections are the least expensive way to go, but they are also very painful. The deep-muscle injections are given every 10 to 21 days.
Blood levels peak and decline slowly until the next injection.
The fluctuations in serum levels of testosterone may be accompanied by changes in mood and sense of well-being, according to The Endocrine Society. Similar to the gel, patches are easy to apply and provide continuous delivery of testosterone. The gel, however, eliminates three problems some consumers have with the patches. It doesn't peel off. Some of the patches that cause less irritation tend to be less adhesive, especially during exercise.