Medications
Supplements and ADHD stimulant (amphetamine type)
Adderall, Vyvanse/Elvanse, Dexedrine, Mydayis — not methylphenidate (Ritalin, Concerta)
Timing
- Keep Vitamin C at least 2 hours from your ADHD medication.
Caution
Vitamin C can lower amphetamine levels. The Adderall XR and Vyvanse labels say acidifying agents such as ascorbic acid lower amphetamine blood levels. Keep vitamin C supplements and large amounts of juice a few hours from your dose — many people take them in the evening. This doesn't apply to methylphenidate.
St. John's wort with amphetamines: serotonin syndrome risk. Amphetamine labels list St. John's wort among serotonergic products that raise the risk of serotonin syndrome. Avoid the combination unless your prescriber agrees.
5-HTP with amphetamines: serotonin syndrome risk. Amphetamine labels list tryptophan among serotonergic products that raise the risk of serotonin syndrome; 5-HTP is the next step on the same pathway. Avoid the combination unless your prescriber agrees.
Note
Caffeine adds to stimulant side effects. Both are stimulants, so jitteriness, a racing heart and poor sleep can add up. Keep caffeine moderate and early in the day.
- 01U.S. FDA Consumer Update — Spilling the Beans: How Much Caffeine Is Too Much? (2018)
Common questions
Can I take Vitamin C with ADHD stimulant (amphetamine type)?
Vitamin C can lower amphetamine levels. The Adderall XR and Vyvanse labels say acidifying agents such as ascorbic acid lower amphetamine blood levels. Keep vitamin C supplements and large amounts of juice a few hours from your dose — many people take them in the evening. This doesn't apply to methylphenidate.
Can I take St. John's Wort with ADHD stimulant (amphetamine type)?
St. John's wort with amphetamines: serotonin syndrome risk. Amphetamine labels list St. John's wort among serotonergic products that raise the risk of serotonin syndrome. Avoid the combination unless your prescriber agrees.
Can I take 5-HTP with ADHD stimulant (amphetamine type)?
5-HTP with amphetamines: serotonin syndrome risk. Amphetamine labels list tryptophan among serotonergic products that raise the risk of serotonin syndrome; 5-HTP is the next step on the same pathway. Avoid the combination unless your prescriber agrees.
Can I take Caffeine with ADHD stimulant (amphetamine type)?
Caffeine adds to stimulant side effects. Both are stimulants, so jitteriness, a racing heart and poor sleep can add up. Keep caffeine moderate and early in the day.