Menstrual cups and period underwear: sizes, labels and cost per cycle

Please ask a doctor

Which product suits you depends on your body, your flow and your health, and a gynecologist or doctor can help. This page explains labels and prices. It does not say how well any product works. If you have pain, unusual bleeding or other symptoms, see a doctor. Do not use a product against the instructions on the package.

Menstrual cups: what the label says

• Regulation: in the United States, menstrual cups are regulated as medical devices, and the package carries instructions and safety information. Read all of it, including any warning about toxic shock syndrome, and the directions for cleaning and use.
• Sizes: makers offer different sizes, and the chart on the package describes how a size is chosen. Brands base sizes on different things, such as age, whether the user has given birth, or the shape of the body, and the charts differ. Follow the maker's chart and ask your doctor.
• Material: usually silicone, and some are made from other materials. Check the label, particularly if you have a latex allergy.
• Firmness and shape: cups differ in firmness and shape. These are personal choices, and fit varies between people.
• Replacement: the maker states how long a cup can be used. Follow it, and replace a cup that is damaged or discolored as the maker directs.

Period underwear: what the label says

• Absorbency levels: brands describe them in their own terms, such as light, moderate or heavy. These are not standardized, so read each brand's guide.
• Fabric and layers: usually multiple layers with a moisture barrier. Check the fiber content and what the maker says about the layers.
• Care instructions: follow the label. Many suggest rinsing in cool water before washing, and avoiding fabric softener, which can affect absorbency.
• Fit and sizing: check the size chart, and the return policy.

Our angle: cost per cycle, and the break-even for your cycle

For disposables, multiply the price per piece by the number you use in a cycle. For a cup, divide its price by the number of cycles you will use it, as stated by the maker's replacement guidance. For period underwear, divide the price of the pairs you need by the number of cycles you expect them to last, then add washing. Because flow and cycle length differ from person to person, use your own counts rather than an average. Comparing on cost per cycle shows when a reusable option pays for itself, and when it does not.

1. Count the disposables you use per cycle, and multiply by the price per piece.
2. Divide the reusable price by the cycles you expect to use it.
3. Compare the two numbers, and add washing for underwear.