Premenstrual syndrome (PMS) refers to a condition where individuals experience a range of psychosomatic and behavioral symptoms that occur in a cyclical pattern. These symptoms typically occur during the luteal phase of the menstrual cycle and the days leading up to menstruation. It is important to note that between two luteal phases, individuals are free from these symptoms [1], [2]. The prevalence of premenstrual syndrome (PMS) varies across studies, with surveys indicating that up to 85 % of reproductive-age women experience at least one symptom, while 2.5–3 % suffer from its severe form, premenstrual dysphoric disorder (PMDD). In India, PMS remains an under-researched area in psychiatry. Many cases go undiagnosed due to a lack of medical consultation by women and challenges in clinical recognition, with some healthcare providers viewing PMS as a cultural or social issue rather than a medical condition [3]. Consequently, diagnosis and treatment rates remain low. Research has indicated that women with PMS often face numerous challenges that significantly impact their quality of life. Quality of work life is reduced in 35 % of women with PMS and is significantly associated with their educational status, sexual activity, and occupation [4]. These challenges include legal issues, thoughts of self-harm, reduced productivity at work, social isolation, difficulties in parenting, increased absenteeism from work, strained personal and social relationships, and a higher frequency of hospital visits [5]. “The ACOG definition requires at least one of the six affective symptoms (anxiety, confusion, angry outbursts, irritability, depression, and social withdrawal) and one of the four somatic symptoms (abdominal bloating, headache swelling of the extremities, and breast tenderness) to have been reported five days in late luteal phase in the three previous cycles and to have stopped within four days of the start of menstruation [6].

The causes of PMS are still not fully understood and are believed to be influenced by multiple factors [7]. It is likely that the interaction and biochemical changes between sex hormones and central neurotransmitters, such as GABA, cholecystokinin, and serotonin, play a role [8]. Research has shown that compared to the follicular or mid-luteal phase, PMS patients exhibit a lower response of the neurotransmitter serotonin to its precursor, tryptophan, during the luteal phase. Another potential mechanism currently being investigated is the insufficient inflammatory response to biological or physical stimuli and the presence of oxidative stress. In a healthy human body, metabolic activity, inflammation, and oxidative stress occur as a natural part of physiological processes [5]. Reproductive-age women experience changes in their inflammatory status throughout the menstrual cycle. However, oxidative stress and chronic inflammation are considered potential factors in the development of conditions such as PMS, preeclampsia, endometriosis, and recurrent pregnancy loss [1], [9].

The interventions to treat PMS include pharmacotherapies such as gonadotropin-releasing hormone agonists(GnRH) and oral contraceptive pills, and psychotropic medications (benzodiazepines and selective serotonin reuptake inhibitors) [3], [10]. Although these pharmacotherapies have shown reasonable success rates in treating PMS, they often come with significant adverse effects such as insomnia, dysphoria, nausea, perspiration, muscle cramps, and tremors. Thus, the ongoing challenge is to find a drug that offers maximum effectiveness with minimal side effects [11]. Women affected by PMS often prefer CAM interventions, including supplements and vitamins, over traditional medical or surgical interventions to help manage their symptoms [7]. Recent research has provided evidence that certain vitamins and supplements (such as magnesium, calcium, vitamin B6, D, and E as well as herbal and complementary alternative medicine (CAM) approaches may have an impact on oxidative stress, hormonal profiles, or inflammatory processes in women experiencing PMS [1], [7].

Many plant products are useful for the treatment of PMS symptoms; one of them is Polypodium vulgare L. (Bisfayej), which is easily available and cost-effective. It is a perennial fern having slender knotty rhizomes belonging to the family Polypodiaceae. It is fibrous, having a dark brownish colour on the outside and greenish colour within [12]. P. vulgare has been used as a medicinal plant in Unani medicine and traditional medicine since ancient times. It has been suggested that this substance has therapeutic potential for various conditions, including melancholia (Malankhuliya), epilepsy, dementia (Nisyan), arthritis, abdominal bloating (Nafkh al-Mi’da), abdominal pain, and other neurological disorders. Additionally, it is also known to have diuretic (Mudirr-i-Bawl), brain and heart exhilarant (Mufarrih-i-Qalb wa Dimagh), carminative (Kāsir-i-Riyāh), purgative of black bile and phlegm (Mushil-i-Balgham wa Sawdā) properties [13]. This substance has also been pharmacologically verified to possess a range of properties, including a calming effect, enhancement of memory retention, analgesic properties, aldosterone antagonism, immune-modulating capabilities, antioxidant activity, anti-inflammatory effects, inhibition of cholinesterase, relaxation of smooth muscles, central nervous system (CNS) depression, and impact on dopamine levels [14], [15], [16], [17]. P. vulgare is composed of various inorganic elements (iron, calcium, magnesium, potassium) and organic components (flavonoids, resins, tannins, steroids, and protein) [18]. Flavonoids possess anti-inflammatory properties through their antioxidant activity and ability to modulate signal transduction pathways involved in the synthesis of pro-inflammatory cytokines [19]. Though few studies have been carried out in complementary and alternative medicines to treat the symptoms of PMS [20], [21], [22], [23], [24], [25]. A systematic review and meta-analysis conducted on Randomized controlled trials had explored the effectiveness of several Unani medicinal plants such as Crocus sativus (saffron), Borago officinalis (borage), Vitex agnus-castus (chaste berry), Matricaria chamomilla (chamomile), Zingiber officinale (ginger), Foeniculum vulgare (fennel), and Pimpinella anisum (anise seed) in alleviating symptoms associated with premenstrual syndrome (PMS) [5], [8]. However, up until now, no studies have determined the efficacy and safety of P. vulgare in treating premenstrual syndrome (PMS). Therefore, considering the significant prevalence of PMS in the general population and its impact on women's health-related quality of life, this study was undertaken. The purpose of this trial was to investigate the efficacy of P. vulgare L. compared to a placebo in women experiencing premenstrual syndrome to improve their health-related quality of life (HRQoL).