I'd suggest just changing the location of your sandrena application on the days you get laser done. If your putting it on your stomach, don't do laser over the top. You can apply it to forearms, chest, lower abdomen and all are acceptable and approved. That should make it easy enough to find a spot for application that's not going to get lasered. Hths.
Though you may want to ask this question in the trans-women section, your far more likely to get answers. (even though you don't identify that way necisarrily) I don't believe there's many here who are doing laser hair removal at all in this area. (though I could be quite wrong.) I am doing laser, though I'm not on sandrena. My spouse was on it for a while which is where I've gotten this information
