Period pads and liners, explained

Peel, press, wear, change. A period pad looks simple, yet the pack is full of words: wings, regular, super, overnight, liner. This Column explains disposable period pads and liners: what they are, how they are used, what they are made of, how to dispose of them, and what Canadian rules say. Reusable period pads have their own explainer in this series. This Column does not compare period pads with any other format.

What it is

Canada’s Society of Obstetricians and Gynaecologists (SOGC) describes period pads as having an “adhesive backing” that sticks to the inside of underwear. They come in “different lengths and absorbencies”, and “some have adhesive ‘wings’ that wrap around the sides of your underwear”.

A period pad absorbs. In the words of the US Food and Drug Administration (FDA): “Menstrual pads, which include liners or period underwear, absorb menstrual flow after it leaves the body.” That grouping is American. Canada treats these products differently; see “What the label tells you (in Canada)” below.

Liners are a smaller, thinner kind. The SOGC calls pantiliners “small, thin, disposable absorbent pads” and names “days of light flow” as one time to wear them. You will see both words, “liner” and “pantiliner”. They name the same product.

How it’s used

The adhesive backing holds the period pad to the inside of your underwear. One maker’s instructions add the steps for wings: peel off the strip, then “Fold the wings under and press them onto your underwear.” A period pad without wings is, in the same maker’s words, “only secured by the sticky backing”.

Period pads come in different lengths. In one maker’s range, Regular is 24.5 cm, Super 29.5 cm and Overnight 34.5 cm. Another maker describes night period pads as “extra-long… with a wider back”. Overnight period pads are often the longest in a range. The names and the sizes are each maker’s own.

Sources give different times for changing one:

• Canada’s SOGC says disposable period pads “should be changed every 4-6 hours”.
• SickKids, a Canadian children’s hospital, says: “Both types of pads should be changed every 4-6 hours.” It means disposable and reusable period pads.
• One maker’s instructions say “every 3-4 hours”.
• A US government page says: “Most women change their pads every few hours.”

Liners are used in more than one way. The SOGC names light days. It also names wearing a pantiliner “in combination with a tampon, in case of leaks or discharge”.

A note on words: one source we cite here says “women”. We keep researchers’ words so we report their findings accurately. The Reading Room is for everyone who menstruates.

Overnight period pads are often the longest in a range. The names and the sizes are each maker’s own.

What it’s made of

A disposable period pad looks like one soft strip. Inside, it is built in layers. The European nonwovens industry association (EDANA) counts up to seven parts, from the side that touches skin to the side that touches underwear:

• a top sheet;
• a layer that spreads fluid;
• an absorbent core;
• a back sheet;
• adhesive;
• a release paper, which covers the adhesive until you peel it off;
• a wrapper.

Not every period pad has every part. Materials the industry names include cellulose pulp, cotton, viscose or rayon, polyester, polyethylene and polypropylene. Some cores also contain superabsorbent polymer (SAP). Each maker chooses its own. This Column makes no judgment about any material. “What’s inside a period pad, layer by layer.” takes the layers one at a time.

Care or disposal

Disposable period pads are used once. The SOGC says they “are thrown out after a single use”. SickKids says to “discard disposable pads after a single use”.

One maker’s instructions describe how: roll the used period pad and wrap it in “the pad wrapper from your fresh pad or toilet paper”. The same instructions say to “never flush them down the toilet”. A federal guide from the Department of National Defence says it more broadly: “No period products should be flushed down a toilet…”

Where the wrapped period pad goes depends on your city. Toronto’s Green Bin list for houses includes “Sanitary products (pads, tampons)” (page modified 2026-08-21). That list does not mention liners or wrappers. The Editor checked Toronto’s rules only. Rules differ from city to city, so check your own city’s waste guide.

Reusable period pads are washed, not thrown out. Their care is in “Reusable period pads, explained”.

What the label tells you (in Canada)

Here is what Canadian rules say about period pads and liners, in the rule-makers’ own words.

Employment and Social Development Canada (ESDC), on its page “Requirements for employers to provide menstrual products in federally regulated workplaces”, says: “Menstrual pads aren’t medical devices or regulated in Canada.” ESDC’s page is about supplying products at work. Health Canada’s device classification list has no entry for period pads, so they are not licensed as medical devices. As consumer products, period pads fall under Canada’s general consumer-product safety law, the Canada Consumer Product Safety Act. Canada’s textile labelling rules exempt “Articles that are intended for a one-time use only”, so under those rules disposable period pads don’t need a fibre-content label.

The words on the pack are each maker’s own. Health Canada sets absorbency labels only for tampons. For period pads, there is no Canadian absorbency standard and no required standard test. Each brand decides how to test its products, and is responsible for being able to back what the package says. So “super” or “overnight” on a period pad means what that maker says it means.

How much each format holds, and why the numbers differ, is in the Column “‘Super’ on a period pad and ‘Super’ on a tampon are not the same thing.”

Common questions

Wings or no wings?

Both exist. The SOGC says “some have adhesive ‘wings’”. One maker describes period pads without wings as “only secured by the sticky backing”. This Column does not rank one against the other. Two people choose differently, and both are right.

Is “S” a size or an absorbency?

On a period pad pack, it is whatever that maker says it is. Size and absorbency words on period pad packs are each maker’s own; no Canadian standard defines them. The maker’s own description or chart is the reference.

Can I wear a liner on days without a period?

Some people do. A US health site for teens mentions wearing a pantiliner “to keep your underwear dry”. The US FDA says menstrual pads “can also be used to collect other types of vaginal discharge, if needed”. The Editor describes this use; it is not advice. If your discharge changes, or something doesn’t feel right, that is a conversation for a healthcare provider.

How many period pads a day?

The sources the Editor checked give change times, not a daily count. Each source’s times are listed under “How it’s used”.

Troubleshooting

The period pad bunches or shifts.

Readers describe period pads that crumple or move to the side. One maker’s instructions say to fold the wings under and press them onto your underwear. The same instructions say to stand up and “double check that the middle of the pad is in prime position”. Lengths and shapes differ by maker, so the pack’s description is worth reading.

Wings over period underwear.

Some readers describe wearing period pads over period underwear and finding that the wings get in the way. How to handle this is not described in the sources we checked.

Away from home.

The same steps apply: wrap the used period pad, as one maker describes, and put it in a bin. The federal guide’s line on flushing applies here too.

What this is not

This Column reports what Canadian and US health bodies, Canadian federal departments and makers say about period pads and liners, in their own words. It did not test any product or compare brands. It does not rank period pads against any other format, or one kind of period pad against another. Two people with the same flow choose differently, and both are right.

Next in this series: “Tampons, explained: with and without an applicator”.