New menstrual cup design enhances safety and sustainability

Researchers at McMaster University have developed a new menstrual health product designed to complement and enhance an existing menstrual cup that is safer, easier to use and more environmentally sustainable than current options.

The innovation is part of a broader initiative at McMaster to develop wearable technologies that proactively monitor women's health. As part of this work, the research team has published a perspective review in Nature Communications, outlining how emerging technologies, like this new menstrual cup, can be leveraged to detect infections, monitor reproductive health and improve diagnostics.

The new component, described in a paper published in ACS Applied Materials and Interfaces, is a flushable tablet made from highly absorbent seaweed-based material. It's designed to hold menstrual blood and minimize spills during removal – a common barrier to wider adoption of menstrual cups. This tablet complements the existing Bfree Cup, which is made from lubricant-infused silicone that naturally repels viruses and bacteria and eliminates the need for boiling between uses.

This project opened my eyes to how urgently innovation is needed in menstrual care. There's been little movement in the conversation around menstrual care. Some of that is due to stigma and some is lack of interest, but cups have the potential to make a serious difference in the lives of women around the world."

Zeinab Hosseinidoust, associate professor of biomedical and chemical engineering and co-lead researcher on the team

The research team also included graduate students Shaghayegh Moghimi and Lubna Najm as well as postdoctoral fellow Fereshteh Bayat, who played key roles in developing and testing.

The product was developed in collaboration with Leisa Hirtz, founder of Women's Global Health Innovations located at McMaster's Innovation Park, who approached the researchers.

"Menstrual health is a critical issue for millions of girls and women, particularly those living in poverty in low- and middle-income countries, where access to safe and dignified products remains a barrier to education, employment and social participation. This innovation builds on Bfree Cup's proven technology to support wider adoption and reduce period poverty. The current research also opens the door to advanced diagnostic capabilities that could transform how we monitor and manage women's reproductive health globally," Hirtz says.

Beyond convenience and safety, the technology has the potential to significantly reduce the environmental impact of disposable menstrual products and improve access to menstrual care in lower-income communities. Each cup is designed to last for several years, offering a cost-effective and sustainable solution for users who may not have reliable access to tampons or pads.

Though menstrual cups have long been available, their uptake has been limited due to usability challenges. These new cups address those concerns while opening the door to future health-monitoring capabilities.

The research team envisions future versions of the menstrual products equipped with sensors to detect early signs of infections and blood-borne illnesses – using menstrual blood as a rich source of biological information.

"This could be a new form of wearable technology that could be even more valuable than a smartwatch," says associate professor of mechanical and bioengineering Tohid Didar, who co-led the research. "We have mainly been reactive in terms of women's health. This can give us an opportunity to start being proactive. If we can add simple systems to menstrual products to monitor for infections and conditions, such as endometriosis and UTIs, we could find these problems much sooner. There is a lot to explore in this area."

"Our review underscores how recent advances in biosensors, wearables, and AI can close critical gaps in women's health diagnostics, from reproductive care to cancer and osteoporosis," says Wei Gao, professor of Engineering and Applied Science at Caltech and co-author of the Nature Communications perspective.