Androgel can be used to initiate or maintain the development of male secondary sex characteristics, as well as virilization (clitoral enlargement) and cessation of menstrual periods.
Though testosterone levels return to baseline 48-72 hours after last dose, most changes (such as cessation of the menstrual period and muscle/fat redistribution) reverse if Androgel treatment is stopped; however, voice changes, facial and body hair, genital growth, and male-pattern baldness persist.
Showering 2-6 hours post-dose decreases testosterone by 13%; using lotion on the application site 1 hour after increases testosterone 14%.
Excess testosterone is converted to DHT (which causes male pattern baldness) and estradiol (a form of estrogen), and can therefore cause adverse effects. This makes finding the appropriate dose and getting hormones checked regularly very important.
It is important to apply gel only to the area of your shoulders that can be covered by a t-shirt, since skin-to-skin contact within 2 hours of application can significantly increase testosterone levels in others (research shows a 280% increase in cis women with skin-to-skin contact vs. only 6% if covered with a t-shirt). Also, remember to wash your hands right away afterwards to prevent transmission as well!
You may experience an increase in urinary disorders or other side effects. It is important to continue to perform regular self chest exams to check for lumps if you still have breast tissue (including tissue near the armpits which often is not removed during top surgery). You should also get your blood pressure, red blood cell counts (to monitor for blood clots), cholesterol and T4 levels checked regularly to monitor for these side effects.
Full Review of Research Follows: