Clinical Reference Tool · Pharmacological Equivalencies
Clinical Equivalence Standards
ADHD Medication Conversion Calculator
Calculate bioequivalent dosages between Vyvanse, Adderall XR, Adderall IR, Concerta, and Ritalin. Designed for patients navigating national stimulant shortages, insurance formulary changes, and cross-medication transitions.
Based on 30 mg Vyvanse · Active window: 8–10 hours
Take 10–12.5 mg once daily in the morning with water. Capsules can be swallowed whole or opened and sprinkled onto applesauce.
Active duration is 8–10 hours (vs 10–14h for Vyvanse). Onset is noticeably faster: kicks in within 30–45 minutes compared to Vyvanse's 90–120 minute prodrug delay.
Lisdexamfetamine is an inactive prodrug cleaved into dextroamphetamine (~2.5:1 ratio). A 30 mg Vyvanse capsule delivers ~8.9 mg active amphetamine base, bioequivalent to 10–12.5 mg Adderall XR.
* Medical Notice: Conversions are consensus clinical reference estimates based on published AACAP guidelines and FDA labels. Always confirm dose titration with your prescribing physician.
Clinical Equivalence Reference Chart
Published consensus guidelines from the American Academy of Child and Adolescent Psychiatry (AACAP) and FDA prescribing inserts:
| Therapeutic Tier | Vyvanse (Daily) | Adderall XR | Adderall IR (Total) | Concerta (OROS) | Ritalin IR (Total) |
|---|---|---|---|---|---|
| Starting / Low | 20–30 mg | 5–10 mg | 5–10 mg (2.5–5mg BID) | 18–27 mg | 10–15 mg (5mg BID/TID) |
| Moderate | 40–50 mg | 15–20 mg | 15–20 mg (7.5–10mg BID) | 36–54 mg | 20–30 mg (10mg BID/TID) |
| High | 60–70 mg | 25–30 mg | 25–30 mg (12.5–15mg BID) | 72 mg | 40–60 mg (20mg BID/TID) |
Why Direct Milligram Conversions Do Not Work
A common mistake patients make during pharmacy shortages is assuming a 30 mg pill of one stimulant equals a 30 mg pill of another. In psychopharmacology, milligram weight reflects the molecular composition of the salt or prodrug, not the amount of neurotransmitter stimulated in the prefrontal cortex.
The Prodrug Advantage (Vyvanse)
Lisdexamfetamine is inactive until red blood cell enzymes cleave the L-lysine molecule off the dextroamphetamine base. Because this occurs at a steady rate in the bloodstream, gastrointestinal transit time and stomach acidity have minimal effect on absorption, resulting in a gentle 12–14 hour curve.
The Dual-Bead Mechanism (Adderall XR)
Adderall XR contains 50% uncoated immediate-release beads that dissolve instantly, and 50% enteric-coated delayed-release beads that dissolve approximately 4 hours later. This mimics taking two doses of Adderall IR 4 hours apart, but patient stomach pH can alter the release timing.
For complete price teardowns on generics vs brand-name stimulants, read our guide on Vyvanse generic pricing in 2026 and our analysis of how to save on ADHD medication without insurance.
Frequently Asked Questions
- What is 30 mg Vyvanse equivalent to in Adderall?
- 30 mg of Vyvanse (lisdexamfetamine) is clinically considered approximately bioequivalent to 10 mg to 12.5 mg of Adderall XR (or two 5 mg doses of Adderall IR taken 4 hours apart). The ratio is approximately 2.5:1 to 3:1 because lisdexamfetamine includes the heavy L-lysine amino acid molecule, meaning only about 29.4% of the total capsule weight is pure active dextroamphetamine base.
- How does Concerta convert to Ritalin IR?
- Concerta uses an OROS osmotic pump delivering 22% of its dose immediately, followed by steady release over 10 to 12 hours. 18 mg of Concerta equates roughly to 5 mg of Ritalin IR taken two to three times daily (15 mg total daily). 36 mg of Concerta equates roughly to 10 mg of Ritalin IR taken three times daily (30 mg total daily).
- Can you switch directly between amphetamines and methylphenidate?
- Direct mathematical equivalence does not exist between amphetamine-class medications (Adderall, Vyvanse) and methylphenidate-class medications (Ritalin, Concerta) because they operate through different neurological mechanisms. Clinicians typically initiate cross-class transitions at a conservative starting dose and titrate upward based on therapeutic response and side-effect tolerance.
- What should I do if my ADHD medication is backordered in 2026?
- If your primary prescription is unavailable due to supply chain shortages, contact your prescribing physician with three specific alternatives: (1) an authorized generic equivalent from a different manufacturer, (2) an equivalent dosage of an extended-release alternative (e.g., Vyvanse to Adderall XR), or (3) an immediate-release formulation divided into multiple daily doses.
- How much can I save using GoodRx on generic ADHD medications without insurance?
- Generic Adderall IR typically costs $15 to $30 per month with a GoodRx coupon. Generic Adderall XR runs $25 to $45 per month. Generic Vyvanse (lisdexamfetamine) costs approximately $75 to $120 per month with discount coupons, compared to $380+ for brand-name Vyvanse without insurance.
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