Inconsistent. I decided to see if the test strips were accurate by doing two at a time (back to back) across a couple days. Yesterday I collected urine and tested with a strip from one box, immediately followed by a strip from another box. My thought was, perhaps batches between boxes have variations. There was a 30 point difference for my estrogen! First strip measuring 150, the second 119. My progesterone was also different by one point. I collected my urine this morning and did two strips back to back again, this time from the SAME box. Again, big variation. First strip said it was 113, the second said 138. Needless to say, they are not accurate. I'm always careful to use morning urine, dip precisely 20 seconds on the dot and put in the machine straight away. Because I'm using the app to guide HRT this is very frustrating. I suspect the strips are very vulnerable to deteriorating while in transit in the mail. Exposure to heat or cold perhaps? Or maybe the whole thing just sucks.