i had taken a variety of store bought drug tests with different results. i tried the first check about 3 weeks before my drug test and passed with flying colors. nice solid line and control line. just because i was curious, i bought an at home test and took it first piss of the day. i had a very faint line and the control line. this worried me, so up until about 5 days before my test i worked out with multiple layers of clothing, and ran 3 miles as well as sat in the sauna for a short time afterwards. i drank lots of water, and stopped working out 5 days prior to the test. on the morning of the test, i drank some coffee and a glass of water after my first piss. i used another first check test to test the second piss of the day on the day of the test and it was a nice solid pass. i pissed a few more times, then took the test in the afternoon. i am still nervous because i dont know how much more accurate the test strips at the lab are compared to the at home tests.

Youve freaked out and went thru that sauna regime (which BTW does nothing to help pass a U/A) for nothing. A "faint" line means nothing. There is no meaning attributed to the intensity or width of a line. Even synthetic urine controls (which contain zero drug metabolites) can produce a faint line on an assay. A faint line is still a line. Therefore, all of your home tests had the same result: negative.

A negative is a negative.

The lab assays used for the initial screening function on the same principle as the home assays. Neither are more reliable than the other.