Caring for reusable period products

Switching to reusables like period underwear and cloth pads is fantastic for the environment and kinder to your wallet. Unfortunately, too many brands provide overly cautious care instructions that lead to smelly underwear and premature fabric degradation. Hand-rinsing in cold water, soaking in vinegar, using a fraction of the recommended detergent, and line drying might sound gentle, but these practices often leave behind residual body fluids.

Follow our advice to ensure your reusable period products are thoroughly clean after every wash.

• Why your pads and underwear start to smell
• How to wash reusable period products
  • Key differences between period products and cloth nappies
  • 1. The initial wash – getting most of the blood out
  • 2. The main wash – a robust and thorough clean
• Sanitising reusable period products
  • Used or second-hand items
  • During or after a yeast infection (thrush)
• Key takeaways

Why your pads and underwear start to smell

Have you ever pulled on a pair of period underwear, only to be greeted by a sharp, unpleasant ammonia-like smell as soon as your body warmth hits the fabric?

This pungent odour is a red flag. It indicates that previous washes have not fully removed all biological residue.

Menstrual fluid is composed of 30–50% blood, with the remainder consisting of shed uterine tissue, cervical mucus, vaginal secretions, and naturally occurring bacteria. Vaginal discharge and sweat also naturally contain small amounts of urea.

While fresh blood inside the body is virtually odourless, the scent associated with periods occurs once menstrual fluid is exposed to bacteria and oxygen, triggering oxidation. 

When reusable products sit unwashed after wearing, bacteria continue to feed on organic matter such as proteins, creating a metallic, stale, or fishy smell. Specific bacteria also produce urease, which transforms urea into ammonia.

If your cloth pads or period underwear are not washed effectively, trapped fluid and bacteria remain locked in the fibres, ready to reactivate with body heat the next time you wear them.

How to wash reusable period products

First, avoid soaking. Polyurethane laminate (PUL) layers degrade when submerged for extended periods, and soaking tubs create ideal conditions for bacterial growth.

Just like with cloth nappies, it is crucial to remove soiling and prevent bacterial growth as soon as practical. Leaving period underwear unwashed for multiple days gives bacteria time to thrive and lock bad smells into the fabric, making them harder to get clean.

Key differences between period products and cloth nappies

Cloth pads and period underwear share many characteristics with cloth nappies: both feature multi-layered fabrics, sit against delicate skin for extended periods, and absorb body fluids. Left unwashed, both will develop ammonia.

However, the volume of fluid involved is vastly different. The average period releases between 5 to 80 millilitres (roughly 1 to 6 tablespoons) of fluid over 2 to 8 days. Even with a heavy flow, this total is significantly less than the volume of liquid in a single wee nappy.

Because of this difference in volume, period underwear do not require a routine quite as intensive as cloth nappies. Nevertheless, due to iron oxidation, volatile organic compounds (VOCs), and ammonia development, your reusables will still benefit from some initial treatment. 

1. The initial wash – getting most of the blood out

An initial wash removes the bulk of soiling, preventing bacterial growth and ammonia formation. Aim to do this at the end of each day, or within two days at most. A quick washing cycle (as short as 15 minutes) with detergent is a low-effort way to remove initial soiling.

Alternatively, many members choose to hand-wash their reusables in the sink or shower using body wash, hand soap, or bar soap. Warm to hot water works best. If hand-washing with laundry detergent, consider wearing rubber gloves, as those surfactants can irritate bare skin.

But doesn’t hot water set in blood stains? One of the most persistent laundry myths is that hot water ‘cooks’ or sets blood stains into fabric. Rest assured, hot water will not set menstrual blood (or other body fluids). Washing in warm/hot water (40–60°C) helps break the bonds holding the stains to the fabric. Even when this heat denatures the proteins, it is still able to overcome chemical bonds and remove the stains much more effectively than cold water can.

If you are already washing cloth nappies for children, simply add your reusable period products to the first nappy wash.

After the initial wash, store those items somewhere airy until main wash day. Draping them over the rim of a plastic laundry basket or laundry tub works well.

If you have a light flow and are running a long wash within 24 hours, there is no need for an initial wash. In this situation, skip to the next step.

2. The main wash – a robust and thorough clean

Just like nappies, heavily soiled clothes, tea towels, and socks, your reusable period products benefit from a long, warm/hot wash cycle with a quality detergent.

If you already follow Clean Cloth Nappies’ advice for your general laundry, no extra steps are required. Simply add your reusables to your next long Cottons wash with like colours.

📝 Note: some period underwear contains wool gussets. If applicable, follow our dedicated wool care guidance to protect the fibre integrity.

Sanitising reusable period products

There are some situations in which it is necessary to sanitise your cloth pads or period underwear.

Used or second-hand items

Sanitise second-hand pads and period underwear as you would for second-hand nappies. You may even sanitise them at the same time. The easiest way to do this is with chlorine bleach using our bleach calculator.

If they have coloured cotton, bamboo or flannel-topped components, the fabric can fade in a bleach sanitise. In this situation, use a non-colourfast dilution with our small-scale sanitise method.

During or after a yeast infection (thrush)

Visit your Doctor or Pharmacist to confirm you have a yeast infection and get treatment. If you have a yeast infection before or during your period, you’ll need to sanitise your period underwear or cloth pads to kill the Candida fungus and prevent reinfection.

Key takeaways

Smells in unwashed period products are caused by a reaction between moisture, bacteria, and oxygen, but that doesn’t mean they are difficult to launder.

A robust wash routine using warm-to-hot water and enough of a quality detergent will keep your reusable period products completely clean, fresh, and stain-free for years to come.

While a cold, gentle wash may increase the longevity of a product, at the end of the day, it is more crucial to ensure hygienic laundering, especially for items that sit against a sensitive area of your body. So if we have to choose between keeping a pair of period undies looking pristine or ensuring people don’t walk around with smells and an itch, you know we’re going to pick the latter!