so I was reading wikipedia and found

https://en.wikipedia.org/wiki/Mammary_ridge#Milk_lines_in_humans

"[Recent study] focal fat pads on the front of human torsos are of mammary ridge origin. 8 pairs of fatty mounds were consistently found running along a curved line from the armpits to the groins [...] This finding explains why fat on the front of the body is less responsive to diet and exercise than fat elsewhere in most people -- [...] breast origin and therefore sensitive more to hormonal influence than caloric intake or burn."

so now I'm wondering if there's any SERMs that spare breast growth in the breasts but not mammary tissue elsewhere

to be clear the study is preliminary and n=20 cis people