I have been using these patches for 3 months now. They are fantastic! They stick well and the B12 is in the perfect amount to get me through the day. I used to get B12 shots but not anymore, these are way better. More sustained levels and no running to the Dr's office.They don't last 8 hours. They come off before they have the opportunity to work.This is a scam. All the scientific reviews prove that patches only work if they have barbs that get through the skin so the molecules can enter, or use an agent like dmso. Our skin is made to be a barrier to things entering , plus it would have to have each molecule have a hydrophilic and hydrophobic end. I'm confused because I thought there were laws about false advertising. They obviously would know the studies have proven this is not an effective way of getting vitamins into the body. I wish someone would explain why they are allowed to keep selling this , even after people have gotten sick due to using these patches and having their doctors have to put them on special iron and calcium plus others so they could function again. Why is Amazon allowing them to sell a bogus product? I think they would want to protect their customers !!It really works!I have a kid with ASD diagnostic.And all the vitamins got wrongs with him.I was looking for an alternative and this patches deliver what you want.I am using half twice a week, could be more, but muy Budget don't allow more.?Love it.I have been surprised by the energy I have received using these patches. I never would have imagined such a kick. On a morning where I'm not getting up to speed one of these patches has me moving within 15 minutes.