Evaluation of the Effectiveness of Cinnamon Oil Soft Capsule in Patients with Functional Dyspepsia: A Randomized Double-Blind Placebo-Controlled Clinical Trial

BACKGROUND: Different effects of cinnamon and its oil in traditional medicine in the treatment of diseases, including gastrointestinal diseases, were reported. The aim of this study is to evaluate the efficacy and safety of cinnamon oil (Cinnamomum zeylanicum) in patients with functional dyspepsia in a double-blind, randomized placebo-controlled trial. METHODS: Soft gelatin capsule was made using the rotary die process, and the final capsule was standardized based on its cinnamaldehyde amount and analyzed by high-performance liquid chromatography (HPLC) method. Sixty-four patients with symptomatic functional dyspepsia were randomized to receive cinnamon oil soft capsule (n = 29) or sesame oil soft capsule as placebo (n = 35) for 6 weeks. The primary efficacy variable was the sum score of the patient's gastrointestinal symptom (five‐point scale). Secondary variables were the scores of each dyspeptic symptom including severity of vomiting, sickness, nausea, bloating, abdominal cramps, early satiety, acidic eructation/heartburn, loss of appetite, retrosternal discomfort, and epigastric pain/upper abdominal pain, as well as any reported adverse events. RESULTS: The results showed that, after 6 weeks of treatment, the cinnamon oil and placebo groups significantly decreased the total dyspepsia score compared to the baseline at the endpoint (P < 0.001). However, there was no significant difference between the cinnamon oil and placebo groups in terms of the baseline and endpoint values of the outcome variables (P=0.317 and P=0.174, respectively). Two patients in the cinnamon oil group complained of rashes, and three patients in the placebo group complained of nausea. CONCLUSION: This study showed significant improvements in gastrointestinal symptom score in both treatment and placebo groups. However, there was no significant difference between the cinnamon oil and sesame oil groups in terms of the baseline and endpoint values of the outcome variables. This study was registered as https://clinicaltrials.gov/ct2/show/IRCT20170802035460N2, 29 December 2017, in the Iranian Registry of Clinical Trials with https://www.IRCT.ir.