It is likely to show up on the saliva drug test after days but it depends on the kind of hair follicle set that is used .The normal hair follicle tests have parameters only for cannabis , opioids, alcohol and cocaine. The tests that measure amphetamine are more expensive and not used normally.
Hair follicle drug test used usually in pre-employment uses a band stick which detects the presence of minute amount of it detects a variety of commonly used drugs of abuse. The corresponding drug band lights up for a particular drug.
In case the hair follicle test does come positive you will be asked to show records for to prove that either you were diagnosed with a condition that required amphetamines or were prescribed amphetamines.
Here are the common lag time between the use of drug and detection of the drug on test.
Alcohol 1 Day Opiates - 3 days. Cocaine - 1 day.
Cannabis - one day.
These drugs can remain in the hair follicle up to 4 weeks.