"Low T" is essentially a made-up patho-physiology by pharma. Aside from a few unique cases of hypogonadism, declining testosterone is a normal part of ageing. While testosterone injections will certainly make you feel better/younger/more virile, you have to remember that you're suppressing your endogenous testosterone production and will need additional drugs to get things back up and running once you cycle off. In addition, increased testosterone has been associated with a number of rare, but serious complications, including increased risk of clotting and subsequent CV risk. Last, you're going to basically have to stay on this for life. Not saying it's the worst option for many, but it's important to consider the long game in this algorithm.