India’s decision to regulate reusable menstrual products under the Bureau of Indian Standards (BIS) is an important milestone for women’s health and consumer protection. BIS Standard IS 17514:2021, which covers reusable sanitary pads and period panties for external use, represents one of the first formal attempts to bring structure and accountability to a category that has expanded rapidly over the last decade. This is, fundamentally, a positive development.
Whenever a product category grows quickly, standards become essential. They establish common expectations around quality, performance, labelling and safety. They help consumers make informed choices and provide manufacturers with a framework for responsible innovation. However, standards are only as strong as the assumptions upon which they are built. And that is where the conversation becomes important.
Period panties
A period panty may be manufactured by the textile industry, but it is not simply another textile product. Unlike a T-shirt, a pair of leggings or even most intimate apparel, it is designed to interact directly with menstrual fluid and remain in prolonged contact with one of the most biologically sensitive areas of the female body.
Traditional textile standards are designed to evaluate parameters such as durability, washability, colour fastness, absorbency and fabric performance. These are important measures. But products intended to manage menstrual flow exist at the intersection of textiles, microbiology, gynaecology and women’s health. The closer a product comes to functioning as a health-management product, the more medically informed its standards should become.
Menstrual product evaluation
Historically, menstrual products have often been evaluated using water, saline or laboratory fluids that are easier to standardize and measure. While practical from a testing perspective, these fluids do not fully represent the biological reality of menstruation. Menstrual fluid is not simply blood. It contains blood, endometrial tissue, cervical mucus and, in many women, clots. Yet much of the discussion around absorbency continues to rely on simplified testing methodologies.
New Research and studies
Recent research has begun to challenge some of these assumptions. In 2023, researchers at Oregon Health & Science University, led by Dr. Bethany Samuelson Bannow, conducted what is believed to be one of the first studies evaluating modern menstrual products using human blood rather than water or saline. The work, published in BMJ Sexual & Reproductive Health by Erin DeLoughery and colleagues, tested 21 commercially available menstrual products under blood-based conditions designed to better reflect real-world menstruation.
Among the study’s observations was that period underwear absorbed the least amount of blood among the products tested, averaging approximately 2 mL. The researchers also noted that absorbency did not significantly increase with increasing garment size. In other words, larger-sized underwear did not demonstrate meaningfully higher absorbency than smaller-sized versions. The study further observed that period underwear absorbed blood relatively slowly despite marketing narratives that frequently compare such products to multiple tampons.
Perhaps the most important implication is not the number itself, but what the number represents. Millions of women are making purchasing decisions based on absorbency claims that have become central to category marketing. If emerging blood-based testing methods produce substantially different results from traditional methodologies, it raises a broader question about how absorbency claims should be established, communicated and understood by consumers.
Consumers today are routinely exposed to absorbency claims ranging from 20 mL and 30 mL to 40 mL and even 50 mL. Such claims have become central to category marketing and consumer decision-making. This study raises a fundamental question for regulators, brands and retailers alike: if products behave differently when tested with blood than when tested with simplified laboratory fluids, should future testing methodologies more closely reflect real-world biological conditions?
The discussion becomes even more complex when we recognize that not all products commonly referred to as period panties are designed to function in the same way.
Original intent of period panties
In 2009, period panties were originally developed as backup protection. Their purpose was to provide confidence against accidental leakage while a pad, tampon or other menstrual product performed the primary fluid-management function. In such designs, the underwear serves as a secondary protective layer rather than the primary absorbent product.
More recently, a new generation of products has emerged that encourages women to bleed directly into the garment itself, with the underwear acting as the primary absorbent system. While both products may appear similar at first glance, the underlying design philosophies are fundamentally different.
One is intended to help manage occasional leakage. The other is intended to retain menstrual fluid, tissue and clots within the garment itself for extended periods of time. This distinction becomes particularly relevant when absorbency becomes a central feature of both regulation and marketing.
Product design standards
If products intended for direct menstrual fluid absorption perform differently under blood-based testing conditions than consumers might expect from category claims, should they be evaluated under the same assumptions as products whose primary role is stain prevention and backup protection?
Similarly, if one product category is designed to remain in prolonged contact with retained menstrual fluid, while another is not, should standards evaluate them through identical performance criteria? These are not merely product-design questions. They are standards-design questions.
This question becomes even more important when viewed through the lens of women’s health.
A substantial body of research has demonstrated that menstruation itself alters the vaginal environment. Studies by van de Wijgert and colleagues have shown that menstrual bleeding is associated with shifts in the vaginal microbiome, including reductions in protective Lactobacillus-dominated communities and increases in anaerobic bacteria commonly associated with bacterial vaginosis. Menstrual blood also temporarily increases vaginal pH, creating conditions that differ significantly from the non-menstrual state.
While these findings do not establish that any specific menstrual product causes bacterial vaginosis, infection or other health conditions, they do raise legitimate scientific questions.
Menstruation and scientific studies
The concern is not simply whether a textile can absorb fluid. The concern is what happens after absorption. Menstrual blood is a biologically active material. Once retained within layers of fabric and exposed to body heat, moisture and time, it creates an environment that differs significantly from a laboratory absorbency test. Yet very little publicly available research has examined what prolonged retention of menstrual fluid within reusable absorbent garments may mean from a microbiological perspective.
If menstruation itself is known to increase pH and alter microbial populations, should standards for menstrual products also evaluate what happens when menstrual fluid remains in prolonged contact with absorbent textile layers? Should standards assess moisture retention, bacterial growth, odour formation, microbiome interactions and extended-wear conditions? Should they consider not only how much fluid a product can hold, but what biological environment may be created as that fluid remains trapped within the garment?
Dangers of misinformation
A schoolgirl attending classes for seven or eight hours, a woman working a full shift, a commuter travelling long distances, or an athlete spending hours in a warm environment are not laboratory conditions. Real-world use involves heat, movement, humidity, pressure and time. It involves tissue fragments and clots, not simply liquid absorption.
This discussion becomes even more important when products are marketed to adolescents and schoolgirls who may rely on product claims to make decisions about comfort, hygiene and confidence. Yet many of the marketing messages consumers encounter focus primarily on absorbency volume and wear duration.
As a category matures, the conversation may need to evolve beyond how much a product can theoretically absorb and towards what prolonged exposure to retained menstrual fluid means from a biological perspective.
Innovation is essential. But meaningful innovation requires continuous validation through science.
Importance of innovation with empathy
The most successful health-related categories evolved because standards evolved alongside evidence. Medical dressings, baby-care products, skin-contact materials and personal-care products have all undergone repeated revisions as scientific understanding advanced. Menstrual products should be no different.
India has an opportunity to lead globally in this space. Rather than treating standards as static documents, policymakers can view them as living frameworks that evolve as new evidence emerges. Future revisions could incorporate greater input from gynaecologists, microbiologists, epidemiologists and women’s health researchers alongside textile experts. Testing methodologies could move closer to real-world menstrual conditions. Claims could be evaluated through both performance metrics and biological outcomes.
The industry itself also faces important questions.
Future of menstrual products
If future research continues to challenge some of the assumptions upon which current absorbency claims and wear-time recommendations are built, will brands voluntarily revisit their communication? Will marketplaces and retailers demand stronger substantiation? Will manufacturers invest in independent microbiological and clinical studies? Can years of category messaging be responsibly recalibrated if stronger evidence emerges?
These are not questions for regulators alone.
They are questions for every founder, retailer, marketplace, investor and manufacturer participating in the growth of this category.
Because if future evidence reveals that current testing methods do not adequately reflect real-world biological conditions, the implications extend far beyond product design. They touch advertising claims, consumer guidance, marketplace policies, regulatory frameworks and, ultimately, public trust.
Menstrual products should be regulated.
The question is whether we are willing to continually re-examine our assumptions as new evidence emerges, including whether products with fundamentally different purposes should continue to be evaluated under the same framework.
India has the opportunity to become a global leader in this space, not by having standards alone, but by ensuring those standards remain rooted in the best available science. For products worn in intimate contact with the body, women deserve nothing less.
