We recently received this question below via e-mail about interpreting faint lines on urine drug test strips.
Hi was wondering if you could help. I recently purchased some single use cocaine tests strips. One test I did came out with the positive line straight away, then a very faint negative line appeared. When I read info on the leaflet it said that faint lines should be read as negative so I’m now confused. I was sure it was positive as it was so clear and the other line was so faint. Can you help please?
How to interpret a faint line
In this question it is not specified at what time the test was read. It is possible for the test to appear to be a positive result initially ( i.e. no line which then turns negative within the test time (T line visible ) If the test line appears within the specified time in the instructions it is a negative result even if it is very faint. If you are unsure you can always send us a photo of the result and we will be able to advise further.