Inclusion Criteria:
1. Must be 19 - 75 years of age.
2. Have a diagnosed noncancer chronic pain condition including but not limited to neuropathic pain, fibromyalgia, chronic headaches/migraines, back pain, musculoskeletal pain.
3. Currently on a stable dose of opioid therapy on short-acting, long-acting, or combination of opioid medication types, for a minimum duration of 90 consecutive days.
4. History of at least one unsuccessful attempt to taper or discontinue long-term opioid therapy, and has expressed current interest in making another attempt to reduce or discontinue.
5. Able to swallow capsules/tablets.
6. If of childbearing potential, agree to practice an effective means of birth control throughout the duration of the study.
Exclusion Criteria:
1. Have any of the following cardiovascular conditions: uncontrolled hypertension, coronary artery disease, congenital long QT syndrome, cardiac hypertrophy, greater than first degree AV block, cardiac ischemia, congestive heart failure, myocardial infarction, tachycardia, chronic bradycardia, artificial heart valve, a clinically significant screening ECG abnormality, or any other significant cardiovascular condition.
2. Asthma
3. Have moderate to severe hepatic impairment.
4. Chronic pain is due to cancer.
5. Women who are pregnant, who intend to become pregnant during the study, or who are currently breastfeeding.
6. Have a history of stroke or Transient Ischemic Attack (TIA).
7. Meet DSM-5 criteria for severe alcohol or drug use disorders (other than Opioid use Disorder).
8. Nicotine dependence that would prevent the participant from remaining nicotine free for the duration of dosing sessions (i.e., 6-8 hours).
9. Have Epilepsy.
10. Clinically significant sleep disorders such as sleep apnoea not on appropriate treatment.
11. Have Insulin-dependent diabetes.
12. Participants who are or have been taking mood stabilizers (e.g. lithium), SSRIs/SNRIs (e.g. citalopram, venlafaxine, vortioxetine, duloxetine), herbal remedies with serotonin activity (e.g. 5-HTP, St. John's Wort), dopamine agonists (e.g. bupropion), tricyclic antidepressants (e.g. amitriptyline), antipsychotics (e.g. haloperidol), amphetamines (e.g. amphetamine/dextroamphetamine salts, methylphenidate, dextroamphetamine, lisdexamfetamine), monoamine oxidase inhibitors (e.g. isocarboxazid, phenelzine, selegiline, tranylcypromine), alcohol or aldehyde dehydrogenase inhibitors (e.g. disulfiram), and UDG modulators (i.e. UGT modulators such as phenytoin, regorafenib, eltrombopag) during the study or in the preceding 8 weeks.
13. Hallucinogenic or psychedelic drug use within 12 months (i.e. any use of mescaline, 2C-B, psilocybin, LSD, 5-MeO-DMT, ibogaine ayahuasca, MDA, MDMA, ketamine or any related molecules).
14. Meet DSM-5 criteria for schizophrenia spectrum or other psychotic disorders, including major depressive disorder with psychotic features, or Bipolar I or Bipolar II Disorder.
15. Have a first degree relative with schizophrenia, Bipolar I or Bipolar II Disorder.
16. Meet DSM-5 criteria for diagnosis of antisocial or borderline personality disorders.
17. Participants with a history of a developmental disorder.
18. Participants diagnosed with serious comorbidities that may or may not influence mental health in the opinion of the qualified investigator.