Substance · opioid
Methadone
Methadone is a long-acting synthetic opioid used for chronic pain and as opioid-use-disorder treatment. It is not detected by standard "opiates" immunoassays and requires its own assay or appears on 10-panel screens.
Last updated:What is Methadone?
A long-acting μ-opioid receptor agonist with a uniquely long half-life. Workplace and clinical panels include it when monitoring for prescribed use or in clinics treating opioid use disorder.
Panels that include Methadone
What drug tests detect
Drug tests for Methadone typically target the following analytes / metabolites:
- EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine)
Confirmation testing uses LC-MS/MS or HPLC.
Detection windows
| Specimen | Window | Pattern | Caveat |
|---|---|---|---|
| Urine | 3–14 days | typical | EDDP metabolite extends detection; long half-life of parent compound. |
| Saliva | 1–3 days | typical | Oral fluid detection moderate. |
Ranges are approximate and vary by individual physiology, hydration, dose, frequency of use, and lab cutoff. They are not predictive of whether someone will "pass" a test.
Cross-reactivity and MRO interpretation
The following can affect initial immunoassay screening and are normally resolved by mass-spectrometry confirmation and MRO review. None of these are a reason to draw conclusions from a single screening result.
- Verapamil (rare, historical)
- Tapentadol (low)
Sources & references
drugtest.co content is sourced from primary regulatory and clinical references. We do not cite gray-market or "how to pass" sources.