advice: what's the deal with period underwear?

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reader is looking for another way to tame aunt flow.

by maja begovic

published oct 30, 2020

last updated feb 19, 2025

4 minute read

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4 minute read

join the conversation

advice: what's the deal with period underwear?

a reader wonders about the efficacy of period underwear and how exactly they work. getty

dear asking for a friend,

not sure if it’s just covid fatigue, or one more thing that i am unhappy with right now, but i am tired of my period. specifically, i am sick of staining my sheets, worrying about changing tampons, and i hate bulky pads. i’m not sure how i feel about menstrual cups, but i am wondering if period underwear might be a good option? can i wear them to stop leakage at night? and is there something i can do to help reduce a heavy flow in the first place?

signed, that time of the month

dear that time of the month,

just like menstrual cups, period underwear is a pretty big deal right now. beyond protecting against leaks, these undergarments — which also claim to protect against the moisture of pee and sweat — are marketed as an effective, bulk-free and eco-friendly alternative to the often messy and non-biodegradable tampons, pads and liners. they look and feel like regular underwear, only they have multiple layers of protection and a barrier to help prevent leakage and get you through those heavy flow days — and nights.

periods can be unpredictable and sometimes, it’s hard to tell if and when you’ll experience leakage. manufacturers of period undies claim that these undergarments can absorb as much as three times the amount of a regular pad or tampon. depending on your flow, these can be used as a standalone option or combined with other menstrual products, and worn throughout the day or at night. after use, you can rinse period underwear, hand wash or toss in the washing machine on cold water cycle and air dry them to avoid shrinkage.

but where does it all go?

“period underwear is made up of three layers at least,” dr. sally hutchinson told abc life. “the inner layer — that’s the layer next to the skin — is a knitted layer that wicks moisture away from the body quickly. it’s generally got a finish on it that makes it water repellent, but it’s got lots of channels in it that allow fluid to move through it and move away from the body.”

according to the research scientist, who works with the commonwealth scientific and industrial research organization in australia, the middle layer is super absorbent, “water-loving material” that “holds on to the fluid.” and finally, there’s the breathable water-impermeable outer layer that prevents leaks.

“[the underwear] feels comfortable and not like you’re wearing a nappy,” hutchinson said.

still not convinced? in a very small study done in may by an australian consumer group, two out of five women who tried period underpants experienced some leakage, which leads us to believe it’s important to make sure you have the right size, and one that fits your flow.

there’s also smell. periods have a scent, and let’s be honest, it’s not amazing. but hutchinson says stink should not be an issue with period undies because many have an antimicrobial agent added to the fabric to kill bacteria. and just so you know, it’s not actually the blood that has a bad odour, she says, but rather, the growth of fungi caused by the dampness of menstrual flow. good to know.

but while these undergarments may guard against leaks, they can’t help reduce a heavy flow.

“the use of menstrual cups and/or period underwear may be worth a try in order to manage the consequences of heavy menstrual flow, but they will not improve the actual amount of flow,” says dr. ashley waddington, obstetrician and gynecologist, assistant professor and co-director of contraception, advice, research and education (care) fellowship at the department of obstetrics and gynecology at queen’s university.

waddington says that a heavy menstrual flow is a common concern for many women, and that any of the hormonal contraceptives available in canada can help reduce menstrual flow. there is also additional medication that is non-hormonal that might help you feel more confident while on your period. “it is available by prescription and is taken only during the days someone is bleeding,” explains waddington. “it works by changing the way the blood is clotting, and results in noticeably lighter menstrual flow.”

for more information on the different options available, waddington urges women to access the society of obstetricians and gynecologists of canada’s menstrual health information portal at yourperiod.ca, sexual and reproductive health information at sexandu.ca and information on contraceptives at itsaplan.ca

while for the most part, online reviewers praise period undies, but a recent report found polyfluoroalkyl substances in one popular brand. typically present in paint, water-repellent fabrics and cleaning products, these chemicals have been linked to cancer and fertility issues.

are they safe?

health canada regulates menstrual products under the food and drugs act (fda) as a medical device and under the canada consumer product safety act (ccpsa) as a consumer product. natalie mohamed, media relations advisor at health canada explains that “manufacturers, importers and distributors of consumer products are responsible for ensuring that their products are safe, comply with all mandatory requirements and do not pose a danger to human health or safety.” companies are required to report any health or safety incidents, and to date, health canada “has not received any reports related to menstrual underwear,” says mohamed.

to find a solution that’s right for you, do your research and be sure to consult with your health care provider if you find that your periods are hard to handle. there are lots of options to help you feel comfortable and confident on your period. you don’t have to just go with the flow.