Can Amoxicillin show up on a drug test? 

Can Amoxicillin show up on a drug test? 

Amoxicillin may show up on a drug test by causing a false positive for Cocaine metabolites. This is not commonly reported, but it is considered a possibility. 

Amoxicillin is an antibiotic and it is not categorized as a drug of abuse and it doesn’t cause any type of addiction. However, it may cause a false positive for Cocaine metabolites, despite having no structural similarity to them (1). 

How long does Amoxicillin stay in your system? 

Amoxicillin has a half-life of about an hour or two. This means that the peak concentration of the drug in your body reduces to half an hour. The remaining concentration keeps reducing in half every 1-2 hours until the drug is completely washed out from your body. 

The process can take up to 10 hours. However, the drug can stay as long as 24 hours in your body

How to avoid Amoxicillin showing up on a drug test? 

You can avoid Amoxicillin showing up on a drug test if you skip a dose and don’t take Amoxicillin in the last 24 hours before your test. However, this is not a good thing to do if you have an active ongoing bacterial infection in your body. 

You can simply provide your prescription to the testing authority before you go for the test. Preliminary urine drug screening is known for causing false positives. 

If your testing procedure is based on Gas Chromatography-Mass spectroscopy (GC-MS), you don’t have anything to worry about as this procedure provides accurate results (2). 

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Alyson Schwebach, Jennifer Ball. Urine Drug Screening: Minimizing False Positives and False Negatives to Optimize Patient Care. US Pharm. 2013;38(12):1-6. Available at:


Ramoo B, Funke M, Frazee C, Garg U. Comprehensive Urine Drug Screen by Gas Chromatography/Mass Spectrometry (GC/MS). Methods Mol Biol. 2016;1383:125-31. doi: 10.1007/978-1-4939-3252-8_15. PMID: 26660182. Available from: