Nipple substance uptake - Scientific paper
So nipple uptake is a form of transdermal uptake (through skin). And this fun article shows about how much the nipple can take up substances through the nipple. Since you apply this locally, the uptake in breast tissue is much higher than if taken systemically (oral pill for example)
I am going to try this out soon with Deer Antler Velvet powder, it has IGF-1 in it which is an essential growth factor for boob growth. I will add random lotion to this, and put a silicone nipple cover on it so I can wear it all day and it can take up the substance. I got those nipple covers from Noogleberry website, but you can buy them anywhere on amazon or ebay. My deer antler velvet is from aliexpres. If it doesn’t work, I will buy better quality deer antler velvet, but hey, no harm in trying the cheapy first right? :) http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0115712