I think I am the can of worms I posted this a couple of weeks ago on the topic of Vitamin patches: I looked into the Patches and was seriously considering using them, because most supplements cause me nausea. I spoke in depth to my surgeon's PA (she has a much better bedside manner!) about them. She has the same issue w nausea, and had looked into them herself. She was skeptical and ultimately decided against them. She told me I should use the patches only as a last resort, as they might be better than nothing. Thankfully she suggested the Multivitamin she takes, and it's easy on my stomach, so that problem solved. When I was considering the patches I also talked to a good friend of mine who's a GI. He very much doubted that most Vitamins and minerals could be absorbed transdermally. I asked him about labs tests to verify, and he said that labs can be very misleading and it can take many months, years, or even decades for deficiencies to show up. He said for instance Calcium will almost never show deficient, our bodies will just take from our bones. And that labs don't even test for all the vitamins and minerals we need. So taking those two opinions, plus my own doubts from this article, stating that the weight of the patch was significantly less than the combined weight of the claimed vitamins and minerals on the patch. https://www.unjury.com/blog/important-information-if-you-are-recommending-a-patch-vitamin/ . It just puts patches into the too good to be true category, and I'm staying away. And then there was this thread very recently. I'm linking from @Matt Z post, and then read down for my and @KimTriesRNY responses