Great topics.

Subcutaneous injections are a perfectly valid way of using Testosterone. We have many patients who choose this route & we have providers who have done this for themselves as well. You hit the main downside, in that you can't inject nearly as much SubQ as you can IM, resulting in more frequent injections (and supply costs). The upside is that it's generally reported as less painful by patients, and from an effectiveness standpoint patients tend to have a more even level as it takes longer to be absorbed from the fat.

You will have modified T levels very quickly with IM or SubQ, but a good effectiveness test would be around 2-3 months. This can be a good number to compare to your starting levels and can show how well you absorb Testosterone. However, the most important metric is how you're feeling. If you're feeling amazing & better than ever with no negative side effects? Then you likely do not need to be tested so soon or as frequently. Feeling like there's no change or that there's potential side effects? It would be good to test around that time to measure the change or have your provider weigh in on what test to get to check out the side effects.