My cursory research says nipple shields do not hinder the excretion of these hormones, but I don't believe it 😃 We successfully breastfed TWICE without the shield and I immediately felt a surge of joy and energy! I know I'm probably just ecstatic to have had success! Also strange but it felt so good to not have that barrier. It was that same joy and relief that came the first time he latched before the shield was recommended to us. When he was young not only were my nipples flat but too large for his small mouth. He's latch and soon after loose his grip and just wasn't able to feed long enough. I was told around 6 months he'd probably remove the shield himself. I didn't feel hopeful and was down on myself. I'm grateful the shield exists! Otherwise we may have been forced to supplement. Which would have been much worse for my confidence as a mom. But I still hate the damn thing! Taking it everywhere, clogged ducts etc. So happy we succeeded! I hope to be rid of the thing forever soon as we hope to continue breastfeeding till his 18 month vaccines!