welcome to just answer
are you present online?
My question is which drugs/chemicals can create false positives for Methamphetamines specifically, not amphetamines. Also, the last sentence of your answer is unclear - can you clarify please?
I believe that the other experts answer is completely misleading.
While there are a number of medications that have been reported to cause false positives on immunoassay (screening) tests, but these will NOT cause false positives on a GC/MS confirmed drug test.
If you did not use methamphetamine, and the drug test was not confirmed with GC/MS, then you should immediately contact the laboratory to have the GC/MS test to confirm the report. This will eliminate the possibility of a "false positive".
The ONLY over-the-counter medication that can theoretically cause a positive GC/MS test is the Vicks inhaler. The Vicks inhaler actually contains l-methamphetamine. Additional entantiomer testing must be done by the laboratory to exclude illegal drug use (that would include d-methamphetamine).
Here is information on this particular type of testing: