Dear Rebecca, I found the heel patches i recently purchased to be very effective in preventing blisters which is a novelty for me as i have had issues with my heels for years. Having said that one patch did not stay attached to the heel of my boot for long and the other patch is more slowly detaching. I admit i did not press firmly for the full 30 seconds when attaching the patches, it was more around half that time though i did wear the footwear for 1 hour after applying the patches. Because of the success i had initially in preventing blisters i am intending to purchase more and this time ensure i apply the patches as per the instructions more fully. Thankyou and regards, Martin