Inclusion Criteria:  Age 18- 70years Diagnosis of current moderate or severe OUD in the past 6 months, including the past one month Willing to receive study interventions and buprenorphine during the study Do not meet criteria for current moderate or severe use of other substance use disorders (except nicotine use disorder) Diagnosis of Major Depressive Disorder, Anxiety disorders, and Post-traumatic Stress disorders will be included as long as the symptoms are stable, no suicidal ideas or plans and there are no recent changes in treatment of these conditions in the last 6 weeks prior to enrollment No intranasal disease Willing to participate by signing the informed consent form and Have a place to stay when receiving the intervention.  Exclusion Criteria:  Any significant neurologic disease such as stroke, dementia, meningitis, neurosyphilis, cerebral palsy, encephalitis, epilepsy or seizures Mental retardation Schizophrenia or bipolar disorders Experiencing current suicide ideas or plans Any unstable medical condition such as uncontrolled hypertension, uncontrolled diabetes, and liver cirrhosis, as determined by site PI History of severe traumatic nose injury that affects ability to smell, as determined by site PI Allergies or intolerance to aromas from plant essential oils (e.g. orange and lemon) Breastfeeding or Pregnancy test positive. On parole or probation mandated to receive treatment for OUD.