Press release: New study shows menstrual cups have a positive effect on vaginal health

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New evidence proves that using a menstrual cup to manage your period does not affect the natural bacterial balance (PH levels) in the vagina and can actually improve your vaginal health. Good vaginal health reduces the risk of infections, maternal and newborn health, and long-term fertility complications.

What is a menstrual cup?

Menstrual cups are a period management device which is inserted in the vagina during menstruation to collect menstrual blood and are a way of managing your period. They are made of medical grade silicone, rubber, latex, or elastomer.

The study

The menstrual Cups or Cash for Girls (CCG) trial is the first to assess the impact of using a cup on girls’ health. The study involved 4,137 Kenyan schoolgirls with an average age of between 16-18 years. It was funded by the UK Department of Health and Social Care, Foreign, Commonwealth & Development Office, Medical Research Council, and Wellcome.

First author of the study, Dr Garazi Zulaika explains:

We were interested to know whether a long-lasting, sustainable, and hygienic menstrual solution would be used by girls and be effective in improving their schooling and sexual and reproductive health.”

Photo: Girls in menstrual health study, Western Kenya – Kenya Medical Research Institute. This photo is from the pilot study, which involved primary school children in the same area.

The findings

86% of the girls provided with cups said they used their cup. Girls who were given cups saw a 33% reduction in HSV-2 (Human Simplex Virus 2) compared to the control group. This is important because having HSV-2, the virus that causes genital herpes, triples an individual’s risk of becoming infected with HIV.

There was a 24% reduction in bacterial vaginosis for girls given cups, compared to the control group. In keeping with this, there was a 37% relative increase in ‘good bacteria’ (Lactobacillus crispatus), indicating cups did not disrupt the ‘good bacteria’ in the vagina, but could actually improve it. Symptoms of bacterial vaginosis can include vaginal discharge, fishy smell, itching, and feeling uncomfortable; having it can double a person’s risk of getting a sexually transmitted infection (STI), and in pregnancy, can increase risk of miscarriage and preterm birth.

Although the study took place among schoolgirls, the researchers hypothesize the beneficial results to vaginal bacteria  may also be seen in women using a menstrual cup.

Prof. Supriya Mehta, Principal Investigator of the vaginal microbiome sub-study funded by the United States National Institutes of Health states:

Good vaginal health helps protect women and girls against infections and poor maternal outcomes. Menstrual cups can be a multipurpose tool to address menstrual health and reproductive tract health.

Sexual health training

The girls that took part in this study were also provided training to better understand their sexual and reproductive health.

Prof. Penelope Phillips-Howard, Professor of Public Health Epidemiology from the Liverpool School of Tropical Medicine, and Principal Investigator of the clinical trial notes:

Alongside the positive effects of using cups to manage menstruation, our research illustrates that menstrual cups have additional benefits.

Ms Elizabeth Nyothach the Kenyan trial manager at the Kenya Medical Research Institute partnering the study explains

Menstrual cups can be used for up to ten years, offer long term health benefits, reduce waste, and provide financial savings as there is no longer a need for menstruators to buy single use pads and tampons every month.

One girl participant said:

…if you have the moon cup, you are going to school, education is just normal, you are just normal and you are free. No one can read what’s going through your mind, it is very difficult for someone to know that you are undergoing your monthly periods, you are confident, and you are laughing meaning that you are free.

Photo: Girls in menstrual health study with a menstrual cup, Western Kenya – Kenya Medical Research Institute. This photo is from the pilot study, which involved primary school children in the same area.

Cups are an environmentally positive product

Alethea Osborne, Deputy Director of the Menstrual Cup Coalition, shares:

In addition to the positive effects seen on vaginal health, cups also have huge climate credentials with only 1.5% of the environmental impact of other period products. The plastics in other products take 500 years to biodegrade and just one person’s lifetime of using pads or tampons is the equivalent of over 4,000 plastic bags being added to landfill or oceans.

Details of the study

The Kenyan trial took place in 96 secondary schools across rural western Kenya. The study split the girls into four groups, providing girls with a menstrual cup, cash alone, a cup and cash, the remaining girls continued their usual menstrual practice, but were also provided with cups at the end of the study. Uptake of the cup, girls’ behaviours, and their health were monitored throughout the study.

More information on the Cash for Girls study.

More information on the vaginal microbiome sub-study.


Notes to editor

Refer to the two published papers:

Liverpool School of Tropical Medicine

Liverpool School of Tropical Medicine (LSTM) is the world’s oldest centre of excellence in tropical medicine and international public health. It has been engaged in the fight against infectious, debilitating and disabling diseases since 1898 and continues that tradition today with a research portfolio over £320 million and a teaching programme attracting students from over 65 countries.

For further information please visit

Menstrual Cup Coalition

The Menstrual Cup Coalition (MCC) is a diverse women-led organisation, fighting for menstrual and climate justice. The MCC provides guidance and grants to grassroots organisations to deliver innovative menstrual health projects in socio-economically disadvantaged communities using menstrual cups. We distribute menstrual cups to those who need them but cannot afford or access them, and provide training on how to use them, and on reproductive health. Menstrual cups have economic and environmental benefits, and empower women, providing them with the freedom to live their lives as they wish during menstruation. Following the distribution of menstrual cups, we gather evidence to evaluate the impact of our work and use the latest research in menstrual health to ensure our practices are up to date.

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Authors: Supriya Mehta, Garazi Zulaika, Penny Phillips-Howard and colleagues

Supriya Mehta, Adjunct Professor, Epidemiology and Biostatistics, University Illinois Chicago (UIC), School of Public Health

Garazi Zulaika, Post-doctoral Research Fellow Department of Clinical Sciences, Liverpool School of Tropical Medicine

Professor Penelope Phillips-Howard, Professor of Public Health Epidemiology from the Liverpool School of Tropical Medicine

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