Vyvanse Clearance Timeline
Vyvanse (lisdexamfetamine) is essentially cleared from your system within 2-3 days after the last dose, with the active metabolite d-amphetamine being 95% eliminated within 48 hours. 1, 2
Pharmacokinetic Profile
Prodrug (Lisdexamfetamine) Elimination
- Lisdexamfetamine itself is rapidly eliminated with a half-life of less than 1 hour 1, 3
- Plasma levels of the intact prodrug become undetectable by 6-8 hours after administration 1, 3
- The prodrug is converted to d-amphetamine in red blood cells through enzymatic hydrolysis, not in the liver 1
Active Metabolite (d-Amphetamine) Elimination
- d-Amphetamine has a half-life of 10-11.3 hours in adults 1, 4
- 95% of d-amphetamine is eliminated within 48 hours after the final dose 2
- Steady-state d-amphetamine levels are reached by day 5 of daily dosing 2
- Peak plasma concentrations occur at approximately 4.4 hours after ingestion 1, 4
Complete System Clearance
For practical purposes, Vyvanse is cleared from the body in 2-3 days:
- After 48 hours: 95% of the active d-amphetamine is eliminated 2
- After 72 hours (3 days): Essentially complete elimination, given the 10-11 hour half-life means approximately 6-7 half-lives have passed 1, 4
- By 5 days: No detectable accumulation occurs with repeated dosing, confirming complete clearance between this timeframe 2
Urinary Excretion Pattern
- 96% of the administered dose is recovered in urine over 120 hours (5 days) 1, 3
- 42% appears as amphetamine metabolites 1
- 25% as hippuric acid 1
- Only 2% as intact lisdexamfetamine 1
- Less than 0.3% is excreted in feces 3
Clinical Caveats
Factors that may prolong clearance:
- Renal impairment: Since 85-96% is renally excreted, kidney dysfunction will significantly delay elimination 1, 3
- Urinary pH: Acidic urine increases amphetamine excretion, while alkaline urine prolongs it (though this is not explicitly stated in the Vyvanse literature, it applies to all amphetamines) 1
- Age: Elderly patients may have slightly prolonged elimination due to reduced renal function 1
The 2-3 day clearance timeline assumes normal renal function and applies to both single doses and chronic daily use. 1, 2