Agree 100% with above. Don't take PH, they are bad news. Do NOT assume something must be safe because it's legal. It's only legal because FDA doesn't really have the teeth to regulate it. You can boost testosterone naturally to some extent with lifestyle changes, but if you think you may be low you should see a doc and get bloodwork (see the stickies.)
Injectable testosterone is definitely the safest, most effective product out there. Training goals should not be the primary factor, however. TRT is about quality-of-life improvement and your overall health. Body composition changes are just a bonus. This is a serious and generally lifelong commitment, but if you honestly evaluate your situation and decide that you need it, you won't regret it.
Find an open-minded doc and get some labs done, then go from there.