IRCT201211151957N4 IRCT 2012-12-27 Research Institute for Islamic and Complementary Medicine (Tehran University of Medical sciences) Effect of Hanzal oil on pain of diabetic neuropathy Comparison of effect of Citrullus colocynthis oil with placebo on pain in patients with painful diabetic neuropathy 2012-12-21 anticipated 60 Complete https://irct.ir/trial/1550 interventional Randomization: Randomized, Blinding: Triple blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Other design features: Randomization will be conducted by the table of random numbers. Color of oils and shape of containers of drug and placebo are similar. Blinding will be performed in patients, physician, and data analyzer. 2 Diabetic neuropathy. Intervention 1: Group 1: Topical Hanzal oil 5 puffs twice daily on pain area. Hanzal oil has been made by traditional pharmacist in the Research Institute for Islamic and Complementary Medicine. To prepare hanzal oil, aquous extract of hanzal fruits was mixed and heated with twice its volume of sesame oil until the water evaporates and oil remains. Oil for 1 month consumption of each patient is placed in spray containers. Intervention 2: Topical paraffin oil 5 puffs twice daily on pain area. It is placed in spray containers for 1 month consumption of each patient.