I had to see an andrologist about this. He thought the free T level guidelines were a joke. Too many men are low-average yet have all the symptoms of low testosterone.
Rather than try testosterone replacement, we decided to try Clomid. Clomid is a follicle stimulator usually used by women trying to enhance their fertility but it has the same effect on the testes. It was wonderful and worked!
Testosterone is a tricky thing to control. Imagine you have a house furnace that isn't heating a particular room well. You buy a space heater. They're both connected to the same thermostat set to 60 degrees. It doesn't matter which turns-on, the problem is the thermostat is set too low.
The furnace is your testes, the space heater is the testosterone replacement, and the thermostat is your pitiuitary gland. What has to be changed is what the pituitary thinks is normal T levels. If the pituitary sees extra testosterone being added to the body, it throttles production in the testes to try to bring the endocrine system back to what it thinks is normal. Only what it thinks is normal is lower than it should be.
This is why guys on T replacement tend to have atrophied testes. They're not being used because all the testosterone the pituitary mistakenly thinks the body needs is being provided by the replacement drug so the pituitary will shut-down the testes entirely. Clomid tells the pituitary to raise the baseline levels so your own testes produce the testosterone you need. That's a major and not insignificant difference.
When getting tested for andropause or hypogonadism, be sure the endocrinologist or andrologist (if you can find one, they're way too rare) tests free AND bound testosterone levels. This is really important to get an accurate reading. Be prepared for lots and lots of bloodwork.
And lose weight. Excess weight impacts testosterone levels greatly.