Does taking Vyvanse before an amphetamine test affect the result?

Hello,

The active ingredient of Vyvanse is Lisdexamfetamine which, in the body, turns into dextroamphetamine. As we can see from the name of the molecule, dextroamphetamine is a member of the amphetamine family

So yes, it is normal for people who take it to test positive for amphetamines, especially if the drug is taken before the blood test since it is found in higher concentrations in the blood. There are other substances that can cause this type of test to vary as well.

We look forward to hearing from you,

Sarah-Yan Chagnon, pharmacist

Yes, as mentioned above, taking the drug before the test causes the dextroamphetamine concentrations in our blood to be higher when the blood is drawn. Thus, the analysis will detect more of it. If we take the drug afterwards, the test will detect the remaining concentrations of the drug taken in the days before, which will then be less