Diabetic Peripheral Neuropathic Pain (DPN)

The "Cannabidiol for the Treatment of Diabetic Peripheral Neuropathy: Pilot study (CBD-DPN1)" is a double-blinded, placebo-controlled, crossover pilot study evaluating the efficacy of Cannabidiol (CBD) and full-spectrum CBD (fsCBD) tinctures in treating Diabetic Peripheral Neuropathy (DPN)-associated pain. DPN is a common, highly distressing complication of diabetes, characterized by chronic pain and loss of sensory function, for which currently available treatments primarily offer only symptomatic relief. CBD and fsCBD are being investigated for their potential neuroprotective and analgesic effects by regulating inflammation and oxidative stress. The study aims to recruit 12 to 20 adult participants who have mild to moderate DPN. Subjects will receive either an active treatment (CBD isolate or fsCBD in MCT oil, dosed at 50 mg twice daily for a total of 100 mg daily) or a placebo during two sequential 6-week phases. The overall objective of this pilot phase is primarily methodological: to test and refine the clinical protocol, assess patient compliance and acceptability of the CBD formulations, and generate sufficient data to calculate the necessary sample size for a larger, definitive study. Efficacy will be measured using objective and subjective metrics, including DPN severity (DN4 Assessment Tool and DPNCheck™ for nerve conduction velocity) and pain level (PainDetect Questionnaire). Secondary outcomes include evaluating mood (HADS), sleep quality (MOS Sleep Scale), and quality of life (EQ-5D-5L).

The goal of this clinical trial is to determine whether quantitative sensory testing (QST) can be used to classify participants into pain sub-groups and predict who will respond best to certain pain treatments in participants with painful peripheral neuropathy. The analgesic effect is evaluated by measuring pain intensity and Patient Global Impression of Change (PGIC). This study is a 3-period cross-over trial. This means researchers will compare 3 different drugs (pregabalin, duloxetine, and placebo) over a period of 19 weeks. Participants will: * Undergo a quantitative sensory testing (QST) exam. * Provide a blood sample. * Complete questionnaires on the computer. * Take the study drug as instructed.