Uncorrected Proof Jundishapur J Nat Pharm Prod. 2022 November; 17(4):e128406. Published online 2022 October 30. doi: 10.5812/jjnpp-128406. Research Article Comparison of Cinnamon and Vitex on Improving Sexual Function in Postmenopausal Women: A Triple-blind Randomized Clinical Trial Tanya Koliji 1 , Zohrah Keshavarz 1 , Faraz Mojab 2 , Malihe Nasiri 3 and Elham Zare 1, * 1 Department of Midwifery and Reproductive Health, Midwifery and Reproductive Health Research Center, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Department of Pharmacognosy, School of Pharmacy and Research Center of Pharmaceutical Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3 Faculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran * Corresponding author: Department of Midwifery and Reproductive Health, Midwifery and Reproductive Health Research Center, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Email: elhamzare52@yahoo.com Received 2022 May 27; Revised 2022 July 17; Accepted 2022 September 27. Abstract Background: Sexual dysfunction is one of the most common problems following menopause. This study aimed to evaluate the effect of cinnamon and vitex on improving sexual function in postmenopausal women. Methods: This study was a randomized triple-blind clinical trial with a control group. Randomized sampling was used to allocate postmenopausal women into three cinnamon, vitex, and placebo groups of 35. A sexual function index was utilized before and two and three months after the intervention to assess sexual functioning. SPSS version 21 software was used for analysis. Results: The mean age was 54.45 ± 3.73 years. The overall sexual function score in the two cinnamon and vitex groups showed a statistically significant difference before and after treatment compared to the placebo group (P < 0.00). In the vitex group, sex- ual desire (P = 0.00) and arousal (P = 0.02) increased significantly compared to pre-intervention, and this significant increase was observed in the cinnamon group in lubricity (P = 0.00) and sexual satisfaction (P = 0.03). Conclusions: Cinnamon and vitex are effective medicinal herbs to alleviate sexual function. Keywords: Sexual Dysfunction, Menopause, Cinnamon, Vitex Agnus-castus 1. Background Female sexual dysfunction (FSD) is defined as varying degrees of persistent or recurrent decline in sexual activ- ity or sexual aversion, arousal disorder, inability to reach orgasm, and pain during sexual intercourse, as a single complaint or a group of complaints lasting more than six months. The prevalence of sexual dysfunction is higher in postmenopausal women and reaches 68 to 86.5%, de- pending on the study location (1). Most sexual problems in postmenopausal women occur in sexual desire, arousal, orgasm, and sexual activity. Hormone replacement ther- apy improves sexual function in postmenopausal women (2). Major side effects associated with hormone replace- ment therapy include cardiovascular disease, breast can- cer, ovarian and endometrial cancer, stroke, and throm- boembolism (3). In recent years, herbal medicine has become one of the most common options for improving sexual function. Approximately 51% of women use complementary and al- ternative medicine, and more than 60% of them believe that complementary medicine is effective in treating sex- ual dysfunction (4-7). The vitex plant (Vitex Agnus-castus), with the common name "Chaste tree," is a flowering plant of the Verbe- naceae family. This plant is native to Central Asia. Its ex- act mechanism for improving sexual desire has not been proven. However, it seems to reduce the release of follicle- stimulating hormone and prolactin and increase the re- lease of luteinizing hormone from the pituitary gland by affecting the hypothalamic-pituitary axis. Its chemi- cal compounds include flavonoids (casticine, tetramethyl ether, trimethyl ether, hydroxy kaempferol, and querceta- genin), iroid glycosides (genocide and aucubin), essen- tial oils (alpha and beta-pinene, cineole 1 and 8, sabinene, bornyl acetate, and p-cymol), and fatty acids (8-11). Laurus cinnamomum, with the common name "Cinna- mon," is a medicinal plant with various uses. Different parts of this plant, including cinnamon bark, expose many healing properties. In traditional medicine, it is used as the main drug to strengthen the heart, stomach, and in- testines, improve kidney function, and increase sexual po- tency. It contains cinnamic aldehyde, eugenol, tannin, Copyright © 2022, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.