This prospective, randomized, double-blind, parallel-group, sham-controlled, superiority study will evaluate the effectiveness of the NET Device in treating persons with Opioid Use Disorder (OUD) without use of Medications for OUD (MOUD) for persons who have expressed a desire to be opioid abstinent without use of MOUD.

The primary study objective is to determine whether use of the active NET Device produces a clinically meaningful decrease in opioid withdrawal symptom severity from baseline to 1-hour in persons with OUD experiencing moderate or greater symptoms of opioid withdrawal.

The NET Device is an investigational Non-Significant Risk device that delivers alternating current via surface electrodes placed transcranially on the mastoid regions. All participants will be screened and undergo evaluation at Isaiah House, a treatment center located in Willisburg, KY. Individual participant treatment (duration of the active/sham device use) is 1 hour and extendable by participant choice, but not to exceed 7 days, delivered at the inpatient facility (typically 28 days duration), with weekly follow-up assessments (efficacy and safety endpoints) following discharge (by video) for a 12-week outpatient study period. Total elapsed time will typically be 16 weeks.

The primary study endpoint is a clinically meaningful decline in COWS total score (defined as a ≥15% reduction) from baseline to 1-hour after start of active NET stimulation.

The first secondary endpoint is a comparison of the decrease in COWS total scores from baseline to 1-hour after start of intervention for active vs sham.

The second secondary efficacy endpoint is a comparison of the percentage of weeks of abstinence from illicit opioid use without the use of MOUD for active vs sham over 12 outpatient weeks following discharge from residential care.

The secondary safety endpoint is the prevalence of all adverse events (AEs) and serious adverse events (SAEs) assessed from day 1 baseline to the end of study, and adverse device effects (ADEs), serious adverse device effects (SADEs), unanticipated adverse device effects (UADEs), and device deficiencies assessed from day 1 baseline to end of day 7.

Inclusion Criteria:

1. Provision of signed and dated informed consent form.
2. Stated willingness to comply with all study procedures and availability for the duration of the study (including inpatient stay and participation in video assessments and remote drug screens for the duration of the 12-week outpatient study period).
3. Stated desire to be opioid abstinent without medications for treating opioid use disorder.
4. Male or female, aged 18-65 years.
5. In good general health as evidenced by medical history.
6. Meet Diagnostic and Statistical Manual (DSM)-5 criteria for opioid use disorder (any severity level) alone or comorbid with stable medical diseases (except for certain medications below).
7. For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method for the duration of the study.
8. Initiating opioid discontinuation at Isaiah House.
9. Clinical Opiate Withdrawal Scale (COWS) total score is 13 or greater.

Exclusion Criteria:

1. Acute/unstable illness: conditions making it unsafe to participate.
2. Chronic illnesses: primarily seizures and dementing illnesses, including medications for these neurological conditions.
3. Current serious psychiatric disease: psychosis, bipolar disorder.
4. Requiring detoxification from alcohol or benzodiazepines.
5. Current use of anxiolytics, hypnotics (prescription and over the counter), antidepressants, anticonvulsants, sedating histamine-1 receptor subtype antihistamines (non-sedating second generation histamine-4 receptor subtype antihistamines are allowed), prescription and over the counter stimulants.
6. Current diagnosis other than opioid use disorder requiring chronic opioid treatment.
7. Presence of a cardiac pacemaker.
8. Pregnancy or lactation. Females who do not agree to sexual abstinence or are heterosexually active and not using (self-report) medically approved birth control measures (sterilization, tubal ligation, oral/depot contraceptives, abstinence, intrauterine device, barrier method such as condom/foam, or a cervical cap combined with a spermicide), are not eligible.
9. Receiving extended-release buprenorphine (Sublocade) within 300 days of enrollment.

This is a proprietary device and company-sponsored clinical trial. No IPD will be made available.

Daily from the time of initiating device use (inpatient day 1) throughout the remaining inpatient period (up to 28 days), and continuing weekly from post-discharge week 1 throughout the end of the post-discharge period (end of week 12).

AEs were queried systematically throughout the inpatient period and weekly during the post-discharge period.

Sham controls for placebo effects, and is designed to minimize sham recognition by participants, research, and treatment personnel. Active and sham arms will receive identical device care and use instructions, equipment, and attachment locations. Visual cues from the device "heartbeat" indicator (light-emitting diode) indicate the device is working. Sham and active both use the NET device without alteration. Sham uses a lead wire rendered non-conductive beforehand, preventing electrical stimulation. The biostatistician will randomly and uniquely assign a pre-printed Study Device Number (SDN) to each lead wire by overlaying a heat shrink tube, pre-printed with a unique SDN, recording the active and sham assignments. Lead wires are inserted into the device. The biostatistician will keep the data in a secure database and will not be involved in recruitment or study procedures. Unblinding will only occur when necessary for treating an adverse event.