What bothers me about this far as I understand the drug doing the 'work' has bad side effects when given to men. Not as in some percentage of men, but 100% of the men will have unacceptable side effects.
So they're also adding other drugs to try and compensate for those. And of course that doesn't work very well.
Which part? Letrozole, anastrozole, and exemestane (the three biggest AIs) are all incredibly effective at keeping estrogen levels within range given a knowledgable doctor providing supervision.
The biggest problem is that there is a lot of taboo with testosterone treatments and finding a doctor that keeps up to date with the research is incredibly difficult depending on where you are located.