Vyvanse typically clears your system within about 2.5 days (60 hours) after your last dose. That number comes from the half-life of its active ingredient, which averages around 11 hours in adults. It takes roughly 5.5 half-lives for a drug to be effectively eliminated, putting the total clearance window at about 60 hours. However, the exact timeline depends on the type of test being used and several personal factors.
How Vyvanse Breaks Down in Your Body
Vyvanse itself is not an active drug. It’s a prodrug, meaning your body has to convert it before it does anything. After you swallow a capsule, the original compound (lisdexamfetamine) is rapidly broken down, reaching its peak in about 1 hour and then disappearing from your blood with a half-life of less than one hour.
What matters for detection is the active compound your body creates from that conversion: dextroamphetamine. This is the stimulant that actually treats ADHD symptoms, and it takes significantly longer to clear. Dextroamphetamine reaches its peak blood concentration around 4.4 hours after you take Vyvanse, then declines with a half-life of roughly 11 hours. So while Vyvanse itself vanishes quickly, the amphetamine it produces lingers in your body for days.
Detection Windows by Test Type
Drug tests don’t look for Vyvanse directly. They detect amphetamine, the active compound your body produces. How long that’s detectable depends on what kind of sample is collected.
- Urine: Amphetamine is generally detectable for about 2.5 days after a single dose. In people who take Vyvanse regularly, that window can stretch longer, potentially up to a week.
- Oral fluid (saliva): Detection typically ranges from 5 to 48 hours after the last dose, making saliva tests the shortest detection window outside of blood.
- Blood: Amphetamine can be measured in blood for roughly 24 to 48 hours, though blood tests are less commonly used for routine screening.
- Hair: Hair follicle tests have the longest window by far, potentially detecting amphetamine use for up to 90 days.
Standard workplace drug panels are urine-based, so the 2 to 3 day window is the most relevant number for most people. If you have a valid prescription, providing documentation to the testing facility or medical review officer will typically resolve a positive result.
What Speeds Up or Slows Down Clearance
The 60-hour average is just that: an average. Your actual clearance time can shift meaningfully based on several factors.
Urine pH plays a surprisingly large role. Amphetamine is cleared through the kidneys, and acidic urine causes the drug to be excreted much faster. Alkaline urine does the opposite, slowing elimination and raising overall drug exposure. This is why your diet and hydration can subtly influence how long amphetamine stays detectable, though the effect is modest in most people eating a normal diet.
Kidney function is the most clinically significant variable. People with severe kidney impairment clear the drug much more slowly because the kidneys can’t flush it out at a normal rate. The FDA prescribing information specifically notes reduced clearance in patients with poor kidney function. Age ties into this as well, since kidney efficiency naturally declines over time.
Other factors that influence clearance speed include body weight, genetics (some people metabolize amphetamine faster than others), the dose you’re taking, and how long you’ve been taking it. Someone on a higher dose for months will have more drug accumulated in their tissues than someone who took a single pill.
How Long the Effects Actually Last
There’s a difference between how long Vyvanse is detectable on a test and how long you feel it working. The therapeutic effects of Vyvanse typically last around 10 to 14 hours, which is why it’s dosed once per day in the morning. The gradual conversion from the prodrug into active amphetamine is what gives Vyvanse its extended duration compared to shorter-acting stimulants.
After the noticeable effects wear off in the evening, dextroamphetamine is still circulating at lower levels. It’s no longer providing meaningful symptom control, but it remains present in your blood and urine at concentrations a drug test can pick up. This is why the detection window (about 2.5 days) is significantly longer than the period where you feel the medication working.