How long have you been on them, Anjia? I felt like mine ran out early at first. A change in insurance company forced me to switch from generic to brand name after my first month, so I can't say for sure whether it was being on them longer or switching patches, but I don't feel the fluctuation anymore. I suspect it's both reasons. I know the brand name ones I use now are thinner and seem to adhere better, even though I didn't have problems with the others coming off. They just didn't stick as firmly. Like Hurdity, I go 3.5 days, Tues night and Sat morn.