Effects of evening primrose oil on treating painful diabetic neuropathy: a randomized, double-blind, clinical trial

Abstract Objectives Diabetic neuropathy results in chronic pain. Traditional treatments often offer limited relief, prompting the exploration of alternative therapies like Evening Primrose Oil (EPO). This study aimed to assess the efficacy of EPO in the treatment of painful diabetic neuropathy. Methods In this interventional clinical trial, Patients were randomly assigned to three groups. Group A, consisted of 24 patients, received 1,000 mg of EPO soft gel capsules every 12 h. Group B, consisted of 21 patients, received 1,000 mg of EPO soft gel capsules daily. Group C, also with 21 patients, was divided so that half of the patients received placebo capsules daily and the other half every 12 h. After 4 weeks, patients returned, and questionnaires were completed. Statistical analysis of the data was conducted using SPSS version 25. Results Groups A and B showed significant reductions in visual analog scale (VAS) pain scores, with Group A achieving the most improvement (mean pre-test: 5.96; post-test: 4.63). Analysis of covariance (ANCOVA) revealed significant differences in post-intervention scores (p<0.001) for VAS and Neuropathy total symptom score-6 (NTSS-6), indicating effective interventions. Treatment A was more effective than Treatment B for reducing pain (VAS mean difference= −0.52; p=0.044) and McGill Pain Questionnaire (MPQ) scores (mean difference= −9.56; p<0.001). Conclusions EPO could serve as a valuable alternative therapy for managing painful diabetic neuropathy with fewer side effects than traditional treatments. Further research is warranted to validate these results and explore EPO treatment long-term efficacy and safety.