B cup is considered borderline and at that, a smaller B cup. At a C cup right now, it's very likely not going to happen. You'd have to drop over a cup size to qualify and even at that be at a borderline level. Best peri results are A cups really. There's two I know who need to get DI surgery as revisions because it was just too optimistic. DI scars are not always that bad either! As for being a C cup, that's a bigger size, so are your nipples even a good size? One of the guy I know who was borderline and got a peri eventually decided he needs DI because his nipples are just way too big and look like pepperoni slices (his description) and his skin didn't tighten up enough. This guy is actually 19 and super fit. He's got decent pecs but there's just too much skin and the nipples are too big. He wants a less than quarter size areola and about half the nipple he has right now. Do you already have this or would it just look ridiculous without a nipple graft? I think one of the biggest issues people forget with size and deciding whether to get DI is that the smaller cup size you are, the smaller your nipples are likely to be, and if you are bigger, they tend to be stretched and bigger. Big nipples look really weird on guys.
I didn't get a reduction on T, whether I was fit or overweight for a spell last year it make little difference there. On T my hips and butt have drastically changed already, but I was still a C when I went into surgery. It's mostly tissue in there. Very few actually lose much here. It CAN happen, but it's more likely in overweight people who lose fat in that area with fat distribution changes while also actively losing weight. If you're not overweight, there's not much fat in that area to lose.
