Efficacy of Inhaled Cannabis in Diabetic Painful Peripheral Neuropathy

Inclusion Criteria: * Willing and able to provide informed consent * History of diabetes mellitus type 1 or type 2 who have stable glycemia and are maintained by diet or a stable regimen of diabetic therapy for at least 12 weeks prior to screening * Painful diabetic peripheral neuropathy for at least 6 months prior to screening with symmetrical onset confirmed by neurological exam and a score of at least 3 on the investigator section (physical exam) of the MNSI (Michigan Neuropathy Screening Instrument) at screening. * Subject has a pain rating of at least 4 on the 11 point Numeric Pain Scale. * Patient is acceptable for enrollment as determined by the Investigator from the medical history, physical exam finding, 12 lead ECG findings, and clinical laboratory test results. * HbA1C\<11%. * For female patients, a negative urine pregnancy test Exclusion Criteria: * Active opportunistic infections or opportunistic malignancies requiring acute treatment * Current or past cannabis abuse/dependence, or current other psychoactive drug use disorder (e.g. opioids, methamphetamine, cocaine, alcohol) * Presence of significant cardiac or pulmonary disease (e.g., tuberculosis, asthma) * Pregnancy as ascertained by a self-report and a mandatory commercial pregnancy test before any marijuana or placebo consumption condition. * Current serious mental illness--e.g. bipolar disorder, schizophrenia, or other psychotic disorder * Other medical conditions that may lead to peripheral neuropathy * Females who are pregnant or planning pregnancy. * Females of child bearing potential not using a reliable means of birth control. * Lower extremity amputations other than toes. Patients must not have phantom pain from amputated toes. * Other painful conditions or pain of vascular origin that may confound the assessment of PDN. * Subjects with unstable blood glucose level (Fasting\< 70mg/dL or random blood glucose level \> 250 mg/dL)