@cha625eng I dont think its the testosterone itself. Men convert the testosterone into estradiol. Estradiol is important for libido, erections, bone health, and metabolism. It works with Testosterone. Mens normal estradiol should be less than 30. I supplement my testosterone with a compounded cream. I keep my levels between 550 and 650. I also must take an estrogen blocker. Without adding any more drugs I take an over the counter called DIM. (to low of T also changes the ratio)
Since estradiol is also important for men I try to keep mine around 25. Any fluctuations here make my nipples sore. I also will notice a puffiness around the nipple. 550 and above supplemented testosterone for me becomes difficult to keep my estradiol at 25. They both should be monitored.