≥18 years of age

Be currently pregnant, breastfeeding or planning on becoming pregnant during the course of the study

Able to provide informed consent

Have presence of any psychiatric or physical comorbidity that would interfere with study participation

Meet DSM-5-TR diagnostic criteria for Stimulant Use Disorder – Amphetamine-Type Substance (methamphetamine), as determined by a specialist in addiction medicine or psychiatry

Have coexisting dependence on or withdrawal from alcohol, non-prescribed benzodiazepines or GHB, or undergoing treatment for any other substance use disorder which in the opinion of the site principal investigator would interfere with study participation (with the exception of cannabis and nicotine)

Opioid-free for at least 7 days by self-report

Be currently receiving opioid analgesics, or:

1. Dependent on opioids,

2. In acute opioid withdrawal, or

3. Has an anticipated need for opioid-containing medications at any point during the study (eg, planned surgery)

Provide a urine drug screen point of care test positive for methamphetamines (during screening) and negative for opioids (during screening, repeated on the first day of study drug)

Likely or planned surgery, travel, incarceration or other engagement during the study period that may interfere with study participation

Willing to avoid pregnancy for study duration if a person of childbearing potential

Have a history of sensitivity to naltrexone, bupropion or any other components of investigational product

Willing and able to comply with all study requirements, including the ability to store study medications securely

Be currently treated with any other preparation containing bupropion or naltrexone

Agree to use a smartphone to self-report daily adherence to the provided medication and daily methamphetamine use

Have acute hepatitis, liver failure or liver impairment (aspartate aminotransferase or alanine transaminase >5 times upper limit of normal (ULN), total bilirubin>ULN)

Have a seizure disorder or any history of seizures

Have a known CNS tumour

Have a current or previous diagnosis of bulimia or anorexia nervosa

Be concomitantly prescribed MAOIs (at least 14 days should elapse between discontinuation of MAOIs and initiation of treatment with the investigational product)

Have hypertension uncontrolled by a single antihypertensive agent

Currently enrolled in another treatment trial of MAUD or clinical trial which would interfere in participation in this study as determined by the PI