The Effect of Evening Primrose (Oenothera) Oil Capsules on Postpartum Pain in Multiparous Women: A Triple-Blind Randomized Clinical Trial

Document Type : Original Research Article


1 MSc in Midwifery, Department of Midwifery, Student Research Committee, Mashhad University of Medical Sciences, Iran

2 Assistant Professor, Nursing and Midwifery Care Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

3 Assistant Professor, Pharmacological and Medicinal Plants Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

4 Professor, Department of Biostatistics, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran

5 Professor, Women’s Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran


Background & aim: Postpartum pain is a problem of women after delivery. These pains increase with the number of deliveries. Due to the side effects of chemical drugs and the individuals' tendency to use herbal medicines, the present study aimed to investigate the effect of evening primrose (Oenothera) oil capsules on postpartum pain in multiparous women.
Methods: The present triple-blind randomized clinical trial examined 90 multiparous mothers who had had vaginally given birth 2 hours ago and had moderate to severe postpartum pain at Ommolbanin Hospital of Mashhad in 2021. The research units were randomly assigned to three groups, namely intervention, placebo, and control. A capsule of evening primrose oil or placebo was given to the research unit every 8 hours for up to 4 doses. The control group received routine care (acetaminophen tablets in case of pain). Pain severity was measured one hour before and after each intervention using the Visual Analogue Scale (VAS), and McGill Pain Questionnaire at the beginning and end of the intervention. Data analysis was performed SPSS (Ver. 16) software, Kruskal-Wallis test, one-way analysis of variance (ANOVA), chi-square test, and exact chi-square test. The significance level was considered to be 0.05.
Results: The mean severity of postpartum pain after intervention in the group consuming evening primrose oil capsule had a significant decrease (P <0.001) and no side effects in the group evening primrose oil was not observed.
Conclusion: Evening primrose oil was effective in reducing the severity of postpartum pain in multiparous.