Pain and discomfort during and after Root canal therapy is the most bothering part of the endodontic treatment. Many drugs have been prescribed to control or eliminate this pain, most of which have undesirable side-effects. Among these; ibuprofen (50-800 mg) has the most decreasing effect on postendodontic pain. Gastro-intestinal problems, are of most important side-effects of NSAIDs . Zintoma a product from Zingiber Officinale has Anti-inflammatory and subsequently analgesic impressions. This study compares the prophylactic effect of Zintoma on postendodontic pain in teeth with irreversible pulpitis, with that of Ibuprofen and placebo. 90 patients who are to be endodontically treated and volunteer to participate in this Double-blind placebo controlled clinical study were randomly assigned into three thirty-person groups. The main inclusion criteria of this study are; irreversible pulpitis of lower first and second molars needing RCT with VAS of 5 or more, ages between 18 and 65 and no history of conflicting disease. The intervention of this study is drug consumption and main outcome measure is pain severity reported by the patient