Hello Mr. Dumais and thank you for your question,
The most common way to improve your testosterone levels is with use of Androgel (its a testosterone gel that you apply daily to your body). This mode is best tolerated with minimal side effects. Other options include a Testosterone patch and Testosterone injections.
Regardless of which way you decide to administer Testosterone, you will need monitoring of your liver enzymes and PSA (prostate antigen) every 6 months. Because prostate cancer is Testosterone driven, there is a small chance of getting prostate cancer while on Testosterone supplementation (which is why you need monitoring every 6 months instead of a year).
I work with male patients only and many of them are on Testosterone replacement and, thankfully, as of yet none have had any serious side effects at all.
I hope you find this information helpful. Please feel free to follow-up with any other questions you might have.
If you are satisfied with the answer, please do click 'Accept' button so that I may get credit for my work.
Best wishes and good luck,