The short answer: Many patients report feeling much better in 2-4 weeks, and full affects are felt after the first month

Understanding testosterone half-life

Half-life is the point at which medication in the body is reduced by 50%. Testosterone has a half-life of 8-days.

There is a misconception that half-life works like this:

testosterone half-life

The reality is much better and works like this:

testosterone half-life chart

As you can see, the medication levels are slowly reduced. However, during this time patients take continued doses, which looks like this:

testosterone half-life graph

As you can see, it takes time for the results to compound.

NOTE: The chart above is for representational purposes, and assumes once-weekly shots. Patients taking twice-weekly shots, or topical testosterone daily, would have a chart pattern with smaller and more frequent changes.