You don't NEED it. You elect to take it because you don't like the natural symptoms of aging or effects of training.
I am not talking about natural symptoms of aging. I thought I made that pretty clear but let me try again. T levels are falling (as are sperm levels) generation from generation. For example, the normal T level of a 47 year old man is, on average, 20% lower than what it was 20 years ago due to our body reacting to some chemical that we are breathing, eating, drinking. Since this statistic is "on average" there are many men who don't have the issue and many that have experienced a much larger drop than 20%. For these men, I am discussing what is the difference between them supplementing to age appropriate levels (as they have a defined medical issue) versus what are people are taking (ex Dopamine, Insulin, Thyroid)? Add to that question that there is NO proof that supplementing to age appropriate levels gives any advantage over another subject whose T level is already at the accepted level.
I am not talking about natural symptoms of aging. I thought I made that pretty clear but let me try again. T levels are falling (as are sperm levels) generation from generation. For example, the normal T level of a 47 year old man is, on average, 20% lower than what it was 20 years ago due to our body reacting to some chemical that we are breathing, eating, drinking. Since this statistic is "on average" there are many men who don't have the issue and many that have experienced a much larger drop than 20%. For these men, I am discussing what is the difference between them supplementing to age appropriate levels (as they have a defined medical issue) versus what are people are taking (ex Dopamine, Insulin, Thyroid)? Add to that question that there is NO proof that supplementing to age appropriate levels gives any advantage over another subject whose T level is already at the accepted level.