Methadone conversion reference
Check OpioidCalc's OME factors by route, then open the formulation-specific pharmacology, cautions and supporting sources.
Educational reference for qualified healthcare professionals. Conversion factors estimate oral morphine equivalent daily dose. They are not a recommended switching dose. Confirm the result with a current source and local guidance.
Free download · iOS and Android · Optional Pro features
Current OpioidCalc factors
Multiply the dose or delivery rate in the stated units by the factor to estimate mg oral morphine equivalent per day. These are the factors currently used by OpioidCalc. Methadone uses 4.7 when converting methadone to OME.
| Route | Input units | OME factor |
|---|---|---|
| Oral | mg/day | 4.7 |
The reverse conversion is not linear. OpioidCalc uses a dose-dependent equation when converting a total OME to methadone, and caps the displayed starting dose. Specialist review is required.
Review all factors and their limitationsCompare a complete regimen in the app
Formulations and cautions
Choose a formulation to read its pharmacology, population, limitations and source references.
OralDefault in appTablet
App source review: 27 August 2026
View details and sources
Tablet
App source review: 27 August 2026
View details and sources- Peak concentration or effect
- 1 to 7.5 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Duration
- Single-dose analgesic duration 4 to 8 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Elimination half-life
- Highly variable: 8 to 59 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Steady state
- At least 3 to 5 days and sometimes longer
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information2.4 and 12.3. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Offset after stopping
- Slow release from liver and other tissues can prolong effects and toxicity after plasma concentrations fall.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Bioavailability
- 36% to 100%
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Receptor activity
- Mu-opioid agonist; NMDA antagonism has been demonstrated but its clinical contribution is uncertain.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.1 Mechanism of Action. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Metabolism
- N-demethylation to inactive EDDP involves CYP3A4, CYP2B6, CYP2C19, CYP2C9 and CYP2D6.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Active metabolites
- No active metabolite is identified; EDDP is inactive.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Elimination
- Extensive biotransformation is followed by urinary and faecal excretion.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Renal impairment
- Renal pharmacokinetics are not well defined; labels advise lower doses and longer intervals where appropriate.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information8.7 Renal Impairment. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Hepatic impairment
- Hepatic pharmacokinetics are not well defined; use lower doses and titrate slowly.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride tablet prescribing information8.6 Hepatic Impairment. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
OralOral solution
App source review: 27 August 2026
View details and sources
Oral solution
App source review: 27 August 2026
View details and sources- Peak concentration or effect
- 1 to 7.5 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Duration
- Single-dose analgesic duration 4 to 8 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Elimination half-life
- Highly variable: 8 to 59 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Steady state
- At least 3 to 5 days and sometimes longer
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information2.4 and 12.3. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Offset after stopping
- Slow release from liver and other tissues can prolong effects and toxicity after plasma concentrations fall.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Bioavailability
- 36% to 100%
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Receptor activity
- Mu-opioid agonist; NMDA antagonism has been demonstrated but its clinical contribution is uncertain.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.1 Mechanism of Action. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Metabolism
- N-demethylation to inactive EDDP involves CYP3A4, CYP2B6, CYP2C19, CYP2C9 and CYP2D6.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Active metabolites
- No active metabolite is identified; EDDP is inactive.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Elimination
- Extensive biotransformation is followed by urinary and faecal excretion.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information12.3 Pharmacokinetics. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Renal impairment
- Renal pharmacokinetics are not well defined; labels advise lower doses and longer intervals where appropriate.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information8.7 Renal Impairment. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
- Hepatic impairment
- Hepatic pharmacokinetics are not well defined; use lower doses and titrate slowly.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- Methadone hydrochloride oral solution prescribing information8.6 Hepatic Impairment. United States. Source revised 28 April 2026. App review 27 August 2026. Regulatory product information.
OralOral concentrate
App source review: 27 August 2026
View details and sources
Oral concentrate
App source review: 27 August 2026
View details and sources- Peak concentration or effect
- 1 to 7.5 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Duration
- Single-dose analgesic duration 4 to 8 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Elimination half-life
- Highly variable: 8 to 59 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Steady state
- At least 3 to 5 days and sometimes longer
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information2.4 and 12.3. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Offset after stopping
- Slow release from liver and other tissues can prolong effects and toxicity after plasma concentrations fall.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Bioavailability
- 36% to 100%
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Receptor activity
- Mu-opioid agonist; NMDA antagonism has been demonstrated but its clinical contribution is uncertain.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.1 Mechanism of Action. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Metabolism
- N-demethylation to inactive EDDP involves CYP3A4, CYP2B6, CYP2C19, CYP2C9 and CYP2D6.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Active metabolites
- No active metabolite is identified; EDDP is inactive.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Elimination
- Extensive biotransformation is followed by urinary and faecal excretion.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information12.3 Pharmacokinetics. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Renal impairment
- Renal pharmacokinetics are not well defined; labels advise lower doses and longer intervals where appropriate.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information8.7 Renal Impairment. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
- Hepatic impairment
- Hepatic pharmacokinetics are not well defined; use lower doses and titrate slowly.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE oral concentrate prescribing information8.6 Hepatic Impairment. United States. Source revised 27 April 2026. App review 27 August 2026. Regulatory product information.
OralDispersible tablet for oral suspension
App source review: 27 August 2026
View details and sources
Dispersible tablet for oral suspension
App source review: 27 August 2026
View details and sources- Peak concentration or effect
- 1 to 7.5 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Duration
- Single-dose analgesic duration 4 to 8 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Elimination half-life
- Highly variable: 8 to 59 hours
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Steady state
- At least 3 to 5 days and sometimes longer
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information2.4 and 12.3. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Offset after stopping
- Slow release from liver and other tissues can prolong effects and toxicity after plasma concentrations fall.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Bioavailability
- 36% to 100%
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Receptor activity
- Mu-opioid agonist; NMDA antagonism has been demonstrated but its clinical contribution is uncertain.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.1 Mechanism of Action. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Metabolism
- N-demethylation to inactive EDDP involves CYP3A4, CYP2B6, CYP2C19, CYP2C9 and CYP2D6.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Active metabolites
- No active metabolite is identified; EDDP is inactive.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Elimination
- Extensive biotransformation is followed by urinary and faecal excretion.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information12.3 Pharmacokinetics. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Renal impairment
- Renal pharmacokinetics are not well defined; labels advise lower doses and longer intervals where appropriate.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information8.7 Renal Impairment. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
- Hepatic impairment
- Hepatic pharmacokinetics are not well defined; use lower doses and titrate slowly.
Population: Adults described in the cited product information
Applicability: United States
- Limitation: Product-specific evidence; do not transfer to other formulations.
- METHADOSE dispersible tablet prescribing information8.6 Hepatic Impairment. United States. Source revised 4 August 2026. App review 27 August 2026. Regulatory product information.
Sources used on this page
- Methadone hydrochloride tablet prescribing informationUnited States. Revision date 27 April 2026.
- Methadone hydrochloride oral solution prescribing informationUnited States. Revision date 28 April 2026.
- METHADOSE dispersible tablet prescribing informationUnited States. Revision date 4 August 2026.
- METHADOSE oral concentrate prescribing informationUnited States. Revision date 27 April 2026.
Other medicine references
Use the full calculator
Compare opioid regimens and inspect formulation-specific information in OpioidCalc for iOS and Android.