So I had this idea.
They have special medical implants for birth control for women, cows, horses... They slowly release hormones over years.
What if they combined hormone(T) therapy into testicular implants somehow? Generally in cis males the majority of sex hormones come from the testis... I wonder if and how that could work out if they devised testosterone implants.
Just a thought.
Or just a testosterone implant in general even, so the needle routine could stop.