Im not a science guru to say its 100% not possible but in my 2 years of using all the main popular peps, never (knock on wood) have I had even the slightest itch on my nips to ever make me suspect gyno... again thats just me, my personal use and that I would highly doubt it
Just to give further as to what all I have done... g6, g2, hex, cjc1293, cjc1295dac (before the gh bleed discovery lol), pegmgf, igf lr3, sermorelin... dosages as high 300+mcg with g6, g2, and hex too, no issues