Period underwear (also known as menstrual underwear or period panties) are absorbent garments designed to be worn during

menstruation Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycle is characterized ...

. Period underwear is designed like conventional

underwear Underwear, underclothing, or undergarments are items of clothing worn beneath outer clothes, usually in direct contact with the skin, although they may comprise more than a single layer. They serve to keep outer clothing from being soiled ...

but it is made up of highly absorbent fabrics to soak up menstrual blood. Most commercially manufactured period underwear makes use of

microfiber Microfiber (microfibre in British English) is synthetic fibre finer than one Denier (unit), denier or decitex/thread, having a diameter of less than ten micrometre, micrometers. The most common types of microfiber are made variously of polye ...

polyester Polyester is a category of polymers that contain one or two ester linkages in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include some natura ...

fabric. It is recommended that period underwear should be changed at least once every 8-12 hours to ensure optimal hygiene and comfort.

Overview

The market for period underwear has developed as a response to consumer preference moving away from traditional

menstrual hygiene management Menstrual hygiene management (MHM) or menstrual health and hygiene (MHH) is the access to menstrual hygiene products to absorb or collect the flow of blood during menstruation, privacy to change the materials, and access to facilities to dispose ...

products, such as sanitary pads and

tampons A tampon is a menstrual product designed to absorb blood and vaginal secretions by insertion into the vagina during menstruation. Unlike a pad, it is placed internally, inside of the vaginal canal. Once inserted correctly, a tampon is held ...

. Different brands use different, often

patented A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

, technology for anti-microbial action, moisture-wicking and optimal absorption. Julie Sygiel was cited by the

BBC The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...

in 2015 as an early developer of the technology, with her company 'Dear Kate'. Period underwear is considered to be an

eco-friendly Environment friendly processes, or environmental-friendly processes (also referred to as eco-friendly, nature-friendly, and green), are sustainability and marketing terms referring to goods and services, laws, guidelines and policies that c ...

way to cut down on waste and reduce spending. It is estimated that the disposal of menstrual products generates 200,000 tonnes of

plastic waste Plastic pollution is the accumulation of plastic objects and particles (e.g. plastic bottles, bags and microbeads) in the Earth's environment that adversely affects humans, wildlife and their habitat. Plastics that act as pollutants are cate ...

in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

each year.

Nancy Redd Nancy Amanda Redd (born April 28, 1981) is an American author who was Miss Virginia in 2003 and competed in Miss America, finishing in the top ten and winning the preliminary "Lifestyle & Fitness in Swimwear" competition. Redd authored the body ...

, a writer for

The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...

, described the product's features: "some menstrual-underwear styles are gorgeous but leaky, and others have

Hoover Dam The Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado, Black Canyon of the Colorado River (U.S.), Colorado River, on the border between the U.S. states of Nevada and Arizona. Constructed between 1931 and 1936, d ...

–level security but diaper-like silhouettes. The style that will be best for you depends on your period flow and preferences". Some manufacturers of period underwear are extending their ranges into other leak-proof clothes such as

swimsuit A swimsuit is an item of clothing designed to be worn by people engaging in a water-based activity or water sports, such as swimming, diving and surfing, or sun-orientated activities, such as sun bathing. Different types and styles may be worn ...

sportswear Sportswear or activewear is athletic clothing, including footwear, worn for sports activity or physical exercise. Sport-specific clothing is worn for most sports and physical exercise, for practical, comfort or safety reasons. Typical spor ...

and

sleepwear Nightwear – also called sleepwear, or nightclothes – is clothing designed to be worn while sleeping. The style of nightwear worn may vary with the seasons, with warmer styles being worn in colder conditions and vice versa. Some styles ...

. In the United Kingdom, period underwear was subject to

value-added tax A value-added tax (VAT or goods and services tax (GST), general consumption tax (GCT)) is a consumption tax that is levied on the value added at each stage of a product's production and distribution. VAT is similar to, and is often compared wi ...

at 20% until 2024, despite the fact that other menstrual products were exempted from the tax in 2021. The exemption for period underwear was brought in after

tampon tax Tampon tax (or period tax) is a popular term used to call attention to tampons, and other feminine hygiene products, being subject to value-added tax (VAT) or sales tax, unlike the tax exemption status granted to other products considered basi ...

campaigners petitioned for the tax to be removed.

Risks

Some companies (like Thinx, Ruby Love, and Knix) are facing

class action A class action is a form of lawsuit. Class Action may also refer to: * ''Class Action'' (film), 1991, starring Gene Hackman and Mary Elizabeth Mastrantonio * Class Action (band), a garage house band * "Class Action" (''Teenage Robot''), a 2002 e ...

lawsuits for period underwear products that contain potentially harmful toxins like

per- and polyfluoroalkyl substances Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain; there are 7 milli ...

(PFAS) which may be linked to adverse health outcomes like

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

. Thinx settled a lawsuit in January 2023 but made no admission of guilt or wrongdoing in the settlement. Some brands of period underwear have been found to contain

silver Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...

used as an

antimicrobial agent An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used aga ...

. Concerns have been raised about the possible health impact of silver migrating into the body, but limited research has been done and little scientific data exists.

References

{{Menstrual cycle Feminine hygiene Menstrual cycle Sustainable products Women's underwear Women's health

Overview

Risks

See also

References