Menopause is one of the most important stages of a woman’s life, which is characterised by changes in the level of sex hormones, cessation of menstruation, and infertility (Burger et al., 2007). Menopause occurs naturally in most women between the ages of 45 and 52 (Sussman et al., 2015). With the increase in life expectancy, the number of postmenopausal women is expected to reach 1.2 billion by 2030 worldwide and will increase by 47 million new cases each year (Johnson et al., 2019). Menopause is associated with many early and late symptoms (Speroff et al., 2020). Vaginal atrophy, as a late symptoms, refers to the structural changes in the vaginal epithelium caused by estrogen depletion. As a result of these changes, blood flow to the vagina and its moisture is decreased (Tan et al., 2012). Seventy five percent of postmenopausal women suffer from vaginal atrophy (Panjari and Davis, 2011). Vaginal atrophy leads to uncomfortable symptoms such as dyspareunia, vaginal dryness, burning and itching, and an increase in pH (Speroff et al., 2020). Vaginal atrophy can cause sexual dysfunction and have negative impact on women’s quality of life. Considering to these symptoms appropriate intervention is necessary (Vizza et al., 2023).

There are different treatments for vaginal atrophy. Estrogen and hormonal drugs are the most common methods for the relief of vaginal atrophy (Karimi Afshar, 2015). There is an increasing concern regarding the side effects of hormones, so the desire for alternative treatments and complementary medicine including herbal treatments has been increased (Bae and Yoon, 2018, Lima et al., 2013, Poluzzi et al., 2014, Naumova and Castelo-Branco, 2018, Takacs et al., 2019, Sánchez-Borrego et al., 2014, Caruso et al., 2018).

Traditionally various herbal treatments have been provided to eliminate vaginal atrophy, Viola odorata is one of them. V. odorata was also known as Banfsaj in Old Persian. This plant grows natively or naturalised in large areas from Europe and the Middle East to Central Asia and in North America. All the aerial parts of the V. odorata, including the stem, flower, and leaf, have valuable active ingredients including flavonoids, mucilage, violin alkaloids, saponin, and cyclotides (Ahmed et al., 2017). Flavonoids belong to the category of phytoestrogens, which have estrogenic activity but do not have the side effects of estrogens (Lobo, 2007). Mucilage is a compound that dissolves in contact with the desired tissue and produces a viscous and gelatinous substance that has anti-inflammatory, moisturising, and softening properties (Paul, 2014). Saponin stimulates and increases the production of hyaluronic acid in the deep layers of the skin for a long time (hyaluronic acid restores the moisture of the skin) and has antibacterial properties (Boyer et al., 2017). This plant is used orally to treat cough, hoarseness, chest pain, sore throat, bronchitis, nervous tension, insomnia, hysteria, Alzheimer's, and also increased sweating (Ahmed et al., 2017). In a study, the Nasal spray of V. odorata was effective in healing dry eyes (Saffar Shahroodi et al., 2019). Another study found that V. odorata increased memory and can be used to treat Alzheimer's (Saleem et al., 2021). This plant is also used topically to heal various skin diseases. Its syrup, used as an expectorant, reduced bronchial inflammation in paediatric medicine. So far, there was no reported harmful or side effects caused by the use of this plant (Ahmed et al., 2017).

Regarding of V. odorata as a rich source of phytoestrogens in the forms of flavonoid, mucilage with moisturising properties, and saponin in the form of hyaluronic acid, it is possible that this plant is effective in treatment of vaginal atrophy and considering lack of similar study in the literature, this study was conducted to evaluate the effect of V. odorata vaginal suppository on the treatment of vaginal atrophy in postmenopausal women.