Period underwear is a reusable, absorbent menstrual product that has grown in popularity as an alternative to traditional pads and tampons. These garments offer a comfortable and environmentally conscious option for managing a period. Questions regarding their overall safety and potential health risks are important to consider. The safety of period underwear primarily rests on the chemical composition of the materials used and the hygiene practices of the user.
Material Composition and Chemical Concerns
Period underwear is constructed with a multi-layered design, each serving a specific purpose to manage menstrual flow effectively. The innermost layer, which is closest to the skin, is designed to be moisture-wicking, quickly pulling fluid away to maintain a dry surface and prevent irritation. The middle layer is the absorbent core, composed of high-capacity materials like cotton or microfiber blends that lock the fluid away. The outermost layer functions as a leak-proof barrier, often made from materials like polyurethane laminate (PUL), a breathable yet waterproof material that prevents blood from soaking through.
A significant safety concern involves the potential presence of Per- and Polyfluoroalkyl Substances (PFAS), sometimes referred to as “forever chemicals.” These chemicals are valued in textiles for their stain and water-resistant properties, which are desirable features for a leak-proof layer. Research has indicated that some period underwear products contain detectable levels of total fluorine, a strong indicator of PFAS, although this is not universally true across all brands. PFAS exposure is linked to various health issues, including endocrine disruption and immune suppression, though the risk of absorption through the skin from fabric is not fully established.
Consumers should seek out brands that are transparent about their material sourcing and manufacturing processes to mitigate this risk. Manufacturers often utilize third-party testing and certifications to confirm their products are free from these specific fluorinated compounds. Choosing products that explicitly state they are PFAS-free is the best approach for consumers concerned about chemical exposure.
Hygiene and Infection Risk
The moisture-wicking top layer is specifically engineered to keep the skin dry. This is important because warmth and moisture create an ideal environment for the overgrowth of bacteria and fungi. For most users, the risk of common infections like yeast infections or bacterial vaginosis (BV) is generally comparable to wearing traditional menstrual pads. Some period underwear uses materials like bamboo, which may possess natural antimicrobial properties, and its breathable nature allows for better air circulation than some plastic-heavy disposable pads.
Any increased risk of infections like BV is typically linked to wearing the underwear for too long, allowing bacteria to proliferate in the absorbed flow, or improper cleaning that leaves residual bacteria in the fabric. Changing the underwear every 8 to 12 hours, depending on the flow, is recommended to maintain hygiene and prevent bacterial overgrowth.
A major safety advantage of period underwear is the extremely low risk of Toxic Shock Syndrome (TSS). TSS is a rare but serious condition primarily associated with the use of internal menstrual products, such as tampons and menstrual cups. Since period underwear is an external product that allows menstrual fluid to flow out of the body, it does not pose the same risk for menstrual TSS as internal products.
Ensuring Continued Safety Through Proper Care
Improper cleaning can compromise the product’s hygiene and reduce its absorbent function. After wearing, the underwear should be rinsed immediately under cold water until the water runs clear, as this prevents the blood from setting into the fabric fibers. Hot water is not recommended for this initial rinse because it can cook the protein in the blood, causing stubborn stains.
The rinsed underwear should then be washed using a mild detergent, ideally on a cold or gentle cycle in a washing machine. It is important to avoid harsh cleaning agents, such as bleach, as well as fabric softeners. Fabric softeners contain waxes and oils that can coat the absorbent fibers, reducing their capacity to soak up fluid and potentially leading to leaks. Similarly, bleach can degrade the fabric and damage the leak-proof membrane over time.
Finally, the underwear must be thoroughly air-dried, preferably by line drying, rather than being put in a machine dryer. High heat can damage the elastic and the technical fabrics, particularly the waterproof layer, shortening the product’s lifespan and reducing its effectiveness. Complete drying is also necessary to prevent the growth of mold, mildew, or lingering bacteria that could compromise hygiene and skin health.