The availability, effectiveness, and safety of menstrual protection represent a key public health issue. However, research on women's menstrual and sexual health remains extremely limited. Whether societal or pathological, many hypotheses are emerging regarding the effects of menstrual protection products, yet little attention has been given to the products themselves, their societal role, or their physiological and pathological consequences. Internal menstrual products, such as tampons and menstrual cups, are widely used but are subject to limited regulatory oversight, and few studies have investigated their long-term effects on vaginal health.

This study aims to investigate how different types of menstrual protection influence vaginal microbiota, immune responses, and the recurrence of gynecological conditions such as bacterial vaginosis, mycosis, or dysbiosis. Biological samples (vaginal, cervical, urinary, and blood) will be collected to analyze vaginal microbiota composition and local immunity. Participants will be divided into three groups based on their main type of menstrual protection: menstrual cup users, tampon users, and external pad users. The study will compare these groups to assess potential differences in vaginal health and immune response related to menstrual product use.

The aim of this study is to investigate potential links between the type of menstrual protection used and variations in vaginal health, including microbial composition, immune responses, and exposure to environmental pollutants.

The project consists of two complementary components:

- Epidemiological Study: An online survey will be conducted with 1,500 to 1,800 participants, collecting detailed information on the usage habits of menstrual protection products (such as menstrual cups, tampons, and external pads), as well as self-reported symptoms and history of urogenital infections. This dataset will allow for large-scale correlation analyses between menstrual hygiene practices and women's health indicators.

- Clinical Study:

A total of approximately 300 women will be recruited and divided into three groups based on their primary menstrual protection method:

Group 1: Menstrual cup users Group 2: Tampon users Group 3: External sanitary pad users

All clinical participants will undergo a gynecological examination and provide vaginal, cervical, urinary, and blood samples. These biological samples will be used for in-depth analysis across three main areas:

• Microbiology: studying the vaginal microbiota composition and identifying infectious or dysbiotic profiles.
• Immunology: assessing local immune responses, including cytokine levels and antibody titers.
• Toxicology: measuring exposure to potential environmental pollutants through menstrual product use.

Sequencing, immune profiling, pollutant quantification, and cytobacteriological screening will be conducted to evaluate potential differences between groups. These analyses aim to provide a better understanding of how menstrual protection methods may influence vaginal ecosystem balance, immune activity, and overall urogenital health.

Inclusion Criteria:

• Willingness to comply with all study procedures and availability for the duration of the study.
• Female, aged 18 to 49 years.
• In general good health, as determined by medical history.
• Covered by the national health insurance system.
• Willing to sign a written informed consent form.
• Has already experienced menstruation prior to the start of the study.
• No vaginal sexual intercourse within 72 hours before the study visit.
• Has had at least 6 menstrual periods in the past 12 months.

Exclusion Criteria:

• HIV infection.
• Positive diagnosis for chlamydia or syphilis at screening or within 4 weeks prior to screening.
• History of hormonal disorders or menstrual cycle irregularities.
• Metrorrhagia.
• Pregnancy or breastfeeding.
• Family members or close relatives of the clinical or scientific team.
• Treatment with any medication for chronic inflammatory disease or chronic conditions (e.g., cancer, arthritis, transplantation) within the past 12 months.
• Participation in an ongoing clinical trial.
• Receiving or having received antibiotic treatment within the 4 weeks prior to the study.
• Refusal to be informed in case of detected abnormalities.
• Indistinct use of both tampons and menstrual cups.
• Never having had vaginal penetrative intercourse.

The study population includes individuals of the female sex, aged 18 to 49 years, who have already experienced at least one menstrual period and meet the inclusion criteria. Participants are residents of the Île-de-France region and are recruited either through the Alfred Fournier Institute or via an online epidemiological survey.

Participants who wish to be informed about the results of the research will receive information in French about the scientific publications via a newsletter or posts on social media (e.g. mastodon).