How to wash period underwear, any brand

Period underwear is made from absorbent fabric that soaks up blood the way a disposable period pad does. You wash it and wear it again, so how you wash it matters. This Column is for anyone who has periods and owns a pair, or is thinking about one. Where the makers’ instructions differ, it says so, and hands the decision back to the care label.

Start with the label

Makers’ instructions differ, and each maker writes for its own pair. A general routine explains the steps. It cannot replace the instructions for the pair in your hand.

If this Column and your label disagree, follow your label.

Before the first wear

One maker says to wash new pairs before you wear them. Check whether your label says the same.

Rinse

Canadian federal guidance, from the Department of National Defence, says reusable period pads or period underwear “must be rinsed out by hand, using running water until the water runs clear”.

Makers say the same, in cold water. One maker says to rinse right away in cold water, squeezing gently, until the water runs clear. Another maker calls the pre-rinse optional, but helpful against smell and stains.

In practice: hold the crotch of the pair under cold running water, squeeze gently, and repeat until the water runs clear.

Wash, by machine or by hand

Temperature. The makers’ instructions the Editor read say cold water, or cold or warm water up to 30°C. A UK consumer test summarises common advice as 30 to 40°C at most. Federal guidance says most reusable period pads and period underwear last longer when washed in cool water.

By machine. One maker says: a mild detergent and a delicate setting. It also suggests a mesh bag. Another says to wash with similar colours.

By hand. One maker suggests soaking for about 30 minutes in cold water with a gentle detergent, then working the fabric and rinsing. Another says to use a laundry detergent, and to avoid “concentrated soaps or other hand and dish soaps”.

What to leave out

Fabric softener. Several makers and a UK consumer test advise against it. One maker says softener “can decrease their performance and lifespan”.

Bleach. None of the four maker pages the Editor read allows bleach.

Ironing and dry cleaning. Two makers say no to both.

Anything else in the wash. Check your label before you add a product to the load.

Dry: where the makers disagree

Here the instructions part ways.

• One maker: “Hang to dry. Do not bleach, iron, dry clean or tumble dry”.
• Another: lay flat to dry, not in a machine dryer.
• A third: hang to dry where possible, “Otherwise, machine dry on low”.

Three makers, three instructions. Each is written for that maker’s own pair. Your label settles it.

Federal guidance adds that most reusable period pads and period underwear last longer when they are allowed to air dry.

Small or shared spaces. A folding airer in your own room is one option. In a UK consumer test, all the tested pairs were “touch dry after 24 hours hanging on an airer”. In that test, a day was enough.

Between wear and wash day

One maker advises against leaving used pairs in a laundry basket. Another suggests rinsing them and keeping them “somewhere with good airflow” until wash day.

“It still smells”

One maker links smell to timing: blood left to dry in the fabric can become stale, so it suggests rinsing and washing soon after wear.

In a UK consumer test, a few testers noticed “a slight smell from five hours of wear onwards” with some lower-scoring pairs. That was during wear, not after washing.

If a smell stays after washing, the Editor did not find a source that explains why. Check your maker’s care guidance, or contact the maker.

How long a pair lasts

Makers differ, and many give no figure.

• One US maker says to replace its pairs “at 30 washes”.
• A UK consumer test ran 12 machine washes, about 6 to 12 months of use, and checked whether absorbency held.
• One Canadian maker gives no figure, but says hand washing “can help extend the lifespan”.

The number to use is your maker’s.

Away from home, or short of water

Three sourced points may help: federal guidance on rinsing under running water until clear; one maker’s hand soak in a basin; and a UK test in which pairs were touch dry after 24 hours on an airer.

The Editor did not find a source written for washing with very little water. If you have a method that works, tell the Editor.

Reusable period pads: the same idea

Federal guidance gives reusable period pads the same steps: rinse by hand until the water runs clear, wash in cool water, air dry. Reusable period pads will get their own care Column.

What this is not

This Column reports what care instructions say. It did not test any pair or compare brands. It makes no claim about germs, materials or fabric treatments; those belong to other Columns.

Next in the Reading Room: “Do period pads and tampons expire?”