What Does Vyvanse Show Up as on a Drug Test?

October 6, 2025 •

4 min read

Because Vyvanse (lisdexamfetamine) is a prodrug that metabolizes into amphetamine, it will show up as an amphetamine on a standard drug test. It is crucial for individuals with a valid prescription to understand this process, including detection windows and verification steps, to avoid potential complications with employers or legal entities.

Quick Summary

Vyvanse is detected on drug tests as an amphetamine because its active metabolite is dextroamphetamine. The detection windows vary by test type, but a Medical Review Officer (MRO) can verify a valid prescription through a confirmatory lab test to prevent a failed result.

Key Points

Metabolizes into Amphetamine: Vyvanse is a prodrug that breaks down into dextroamphetamine, causing a positive result for amphetamines on a drug test.
Requires Verification: A positive result for a prescribed medication is not a failed test if verified by a Medical Review Officer (MRO) with a valid prescription.
Detection Varies by Test: The detection window depends on the type of test, ranging from hours in blood to up to 90 days in hair.
Confirmation Testing Differentiates: Advanced confirmatory lab tests (like GC-MS) can distinguish between specific amphetamine metabolites, confirming prescribed dextroamphetamine.
Inform and Document: Disclosing your Vyvanse prescription to the testing facility or MRO and having documentation ready is crucial to prevent misinterpretation.
Factors Impacting Time: Dosage, frequency of use, metabolism, hydration, and body weight are all factors that influence how long Vyvanse is detectable.

The Prodrug Mechanism: How Vyvanse Becomes Amphetamine

Unlike many other stimulants, Vyvanse (lisdexamfetamine) is a 'prodrug,' meaning it is inactive until it is metabolized by the body. After oral ingestion, the compound is absorbed through the gastrointestinal tract and then converted into its active form, dextroamphetamine, in the bloodstream. This conversion is what makes Vyvanse detectable on a drug test.

Since dextroamphetamine is the active ingredient in Adderall and is also chemically related to illicit amphetamines, standard drug screenings will flag it. The initial immunoassay screen, often used in preliminary tests, is designed to detect the general class of amphetamines, triggering a positive result for anyone taking Vyvanse. A confirmatory test, typically a more specific and advanced method like Gas Chromatography–Mass Spectrometry (GC-MS), can then be used to differentiate between the various amphetamine types and identify the specific compounds present. This is the key process for distinguishing a prescribed medication from an illicit substance.

Vyvanse Detection Windows by Test Type

The amount of time Vyvanse remains detectable in a person's system varies significantly based on the testing method used. This is due to how the body processes and eliminates the metabolite, dextroamphetamine.

Urine Test: The most common form of drug testing. Vyvanse can be detected in urine for an average of 2 to 5 days after the last dose. Factors like dosage and chronic use can potentially extend this window.
Blood Test: Used less frequently due to its shorter detection window. Vyvanse metabolites can typically be found in blood for up to 24 hours after the last dose, although some sources report a window as short as 7 to 8 hours.
Saliva Test: A minimally invasive method that detects recent use. Vyvanse can be present in saliva for up to 48 hours after the last dose.
Hair Follicle Test: This test has the longest detection window. Hair follicle tests can reveal Vyvanse use for up to 90 days after the last dose. It takes about a week after use for drug metabolites to be incorporated into the hair shaft.

Navigating a Positive Result with a Prescription

If you have a legitimate prescription for Vyvanse, a positive result on an initial amphetamine screen is not a cause for panic. The key is to be proactive and informed about the verification process. Here is a general step-by-step guide:

Disclose Your Medication: At the time of testing, inform the testing facility that you are on a prescribed medication that will likely trigger a positive result for amphetamines.
Provide Documentation: Be prepared to provide proof of your prescription. This could be a copy of your prescription bottle, pharmacy label, or a letter from your doctor.
Medical Review Officer (MRO) Contact: If the initial screen is positive, a Medical Review Officer (MRO) will contact you confidentially. The MRO is a licensed physician who reviews and interprets drug test results.
Verify Your Prescription: You will present your prescription information to the MRO. They will verify that you have a valid prescription and that the dosage is consistent with the levels found in your sample.
Result Confirmed Negative: Once the MRO verifies your prescription, the test will be reported to your employer as a negative result, protecting your privacy.

Factors Influencing Vyvanse Detection Time

Several physiological and usage-related factors can influence how long Vyvanse remains detectable in your system:

Dosage: Higher doses of Vyvanse generally result in a longer detection time.
Frequency of Use: Chronic users may have longer detection windows as metabolites can accumulate over time.
Metabolism: Individual metabolic rate, influenced by genetics, age, and health conditions, can impact how quickly the drug is processed.
Kidney Function: Since Vyvanse metabolites are primarily eliminated through the kidneys, impaired kidney function can extend the detection time.
Hydration: Dilution from high fluid intake can lower the concentration of metabolites in urine, potentially affecting test sensitivity, though this is not a reliable method to pass a drug test.

Comparison of Drug Test Results


Feature	Standard Immunoassay Screen	Confirmatory GC-MS Test
Drug Detection	Detects general class of amphetamines.	Identifies specific amphetamine compounds (e.g., dextroamphetamine).
Accuracy	Prone to cross-reactivity and potential false positives.	Highly accurate and specific, differentiating prescribed vs. illicit use.
Turnaround Time	Fast, often used for initial screenings.	Slower, used for verifying positive screens.
Vyvanse Result	Positive for amphetamine.	Identifies dextroamphetamine consistent with Vyvanse prescription.
Illicit Amphetamine	Positive for amphetamine.	Identifies other amphetamine compounds, potentially including methamphetamine.

Conclusion

Anyone prescribed Vyvanse should know that the medication will cause a positive result on a standard drug test for amphetamines. This occurs because Vyvanse is a prodrug that is converted into dextroamphetamine, an amphetamine, in the body. However, a positive initial screen is not a cause for alarm, provided you have a valid prescription. The process involving a Medical Review Officer (MRO) and a confirmatory lab test is designed to distinguish prescribed use from illicit drug use. The key to navigating this situation successfully is to be transparent about your medication and have your prescription documentation readily available for verification. Understanding how Vyvanse is detected and the verification process can provide peace of mind for individuals undergoing routine drug screenings.

Visit drugs.com for additional information on Vyvanse and its detection.

Frequently Asked Questions

Yes, standard drug tests screen for the general class of amphetamines. Since Vyvanse metabolizes into dextroamphetamine, an amphetamine, it will trigger a positive result on an initial screen.

This is done through a secondary, more specific confirmatory test, such as Gas Chromatography–Mass Spectrometry (GC-MS). This test analyzes the chemical composition and can identify the specific isomers of amphetamine, differentiating prescribed dextroamphetamine from other illicit forms.

Vyvanse is typically detectable in a urine test for 2 to 5 days after the last dose, though this can vary based on individual factors like metabolism, hydration, and dosage.

An MRO is a certified physician who reviews confirmed positive drug test results. They will contact you to verify any valid prescriptions that could explain the positive test before reporting the final result to your employer.

Initial immunoassay screens can sometimes have cross-reactivity and potentially show a false positive for methamphetamine. However, the subsequent confirmatory GC-MS test can accurately differentiate between these substances and clarify the result.

The most effective approach is to inform the testing facility or the MRO, not necessarily the employer directly. This keeps your medical information confidential while ensuring the positive result is correctly interpreted and reported as negative to your employer.

Factors such as your dosage amount, frequency of use, individual metabolism, body mass, hydration levels, and kidney function can all influence the detection window.