7 Things to Know Before Buying Period Underwear: The Ultimate Guide

Period underwear in various styles and absorbency levels.

Period underwear is changing menstrual care with its eco-friendly, cost-effective, and convenient benefits. However, like with anything new, it’s important to be informed before making a purchase. Whether you’re transitioning from traditional menstrual products or exploring new options, here are the seven most important things to know before buying period underwear.

Understand the Different Absorbency Levels

Period underwear comes in different absorbency levels, designed to absorb different amounts of menstrual flow. Understanding your menstrual flow pattern is crucial in picking the right absorbency level. We offer detailed absorbency charts and guidelines on our product pages, or you can take our quiz to find your perfect match.

Here's a breakdown of what you need to know:

Light to Moderate Flow

Ideal for:

Light days, spotting, or as a backup to other menstrual products. At fluxies, we offer a wide range of period pants in light flow and moderate flow. These range from thongs, to cotton hipsters, and seamless briefs


Thin and lightweight for discreet protection. Our Seamless collection is VPL-free, super breathable, and so light you can wear it under anything!

Absorbency Equivalent:

Typically equivalent to 1-2 tampons, or 14ml of liquid.

Heavy Flow

Ideal for:

Heavier days or overnight use. All of our period pants are available in Heavy Flow, including our Classic Collection, Seamless Collection, and Essential Collection.


Thicker and more absorbent layers, ensuring no leaks even during heavy flow.

Absorbency Equivalent:

Equivalent to 2-4 tampons, or 28ml of liquid.

Overnight Protection

Ideal for:

Overnight use, heavy flow days, or for those who want extra security. Why not try our super absorbent Sleep Short, which can keep you covered all day and night!


Extended coverage and extra absorbency.

Absorbency Equivalent:

Can handle heavy flows equivalent to 4 tampons, or 35ml of liquid.

Fabric and Comfort: What To Look For

Comfort is crucial when it comes to period underwear, especially since you'll be wearing them for long stretches of time. The fabric and fit are key factors in making sure you stay comfortable.

Here at Fluxies, we get that comfort and sustainability matter. That's why we've curated a variety of materials that not only feel amazing but also deliver top-tier performance.

Material Matters

There are lots of materials to choose from, each with its own perks to suit different needs and preferences. Here’s a quick rundown of the sustainable fabrics we offer:

Organic Cotton:

Soft, breathable, and hypoallergenic. Ideal for sensitive skin. Try out our Essential Collection if you're looking for super-soft Organic Cotton.


Crafted from beech tree pulp, it's wonderfully soft and eco-friendly. Each modal is unique, and our Classic Collection features TENCEL Modal, sourced from Lenzing, Austria's leading brand. It's incredibly sustainable and luxuriously soft.

Synthetic Blends:

Often feature nylon and spandex for stretch, and polyester for moisture-wicking properties. Our Seamless and Swim Collections use nylon made from post-consumer waste, turning old water bottles into stylish essentials for you!

Breathability and Moisture-Wicking

Fabrics that breathe and wick moisture away help you stay dry and comfortable. Choose underwear with a lot of natural fibres or advanced synthetic blends that handle moisture well. All our period pants come with a built-in panel of breathable, moisture-wicking materials to keep you feeling fresh and dry all day long.

Fit and Stretch


Make sure the underwear stretches enough to move comfortably with your body. Our new one-size period pants are a world-first in one-size-fits-most design, stretching up to 4 sizes with our innovative NuStretch technology, expanding effortlessly by up to 400%.

Elastic Bands:

Check that the elastic bands around the legs and waist are comfortable and do not dig into your skin.

Style Options:

From bikini cuts to high-waisted and boyshorts, choose a style that suits your comfort and lifestyle needs.

Care and Maintenance: Make Your Period Pants Last Longer

Proper care and maintenance is important to keep your period underwear lasting as long as possible. Here's our guide to keeping them in top condition:

Washing Instructions

Rinse First:

Rinse the underwear in cold water immediately after use to remove excess blood.

Machine Wash:

Most period underwear can be machine washed. Use a gentle cycle with cold water.


Use mild, fragrance-free detergent to avoid irritating sensitive skin and degrading the fabric.

Avoid Fabric Softeners or Bleach:

Fabric softeners and bleach can reduce the absorbency of the material.

Drying Tips

Air Dry:

Always air dry your period underwear. The heat from dryers can damage the elastic and the absorbent layers.

Avoid Direct Sunlight:

Prolonged exposure to sunlight can cause the fabric to weaken and fade.

Stain Management

Natural Stain Removers:

Use natural stain removers like baking soda or lemon juice for stubborn stains.

Avoid Bleach:

Bleach can damage the fabric and reduce the effectiveness of the absorbent layers.

Proper care ensures that your period underwear remains hygienic, functional, and long-lasting.

Benefits of Period Underwear

Period underwear is a great choice for the environment and your wallet compared to disposable menstrual products.

Eco-Friendly Choice

Reduction in Waste:

One pair of period underwear can replace hundreds of disposable pads and tampons, significantly reducing menstrual waste.

Sustainable Materials:

At fluxies, we only use sustainable and ethically sourced materials, further reducing environmental impact. 

Recyclable Packaging:

Look for brands that use minimal and recyclable packaging. At fluxies, all of our packaging is 100% recyclable and made from recycled materials.


Initial Investment:

While period underwear may have a higher upfront cost, they pay for themselves over time.


With proper care, a single pair can last up to 2-3 years. 


Calculate the cost savings from not purchasing disposable products each month to see the long-term benefits. 

Supporting Sustainable Brands

When you go for period underwear, you're backing brands like Fluxies dedicated to sustainability and ethical standards. We partner with numerous charities and initiatives, championing menstrual health and donating products to those who require them. Your choice makes a positive impact beyond your own comfort.

Health and Hygiene

Making sure your period underwear meet health and hygiene standards is super important for your well-being.

Antimicrobial Properties

Naturally Antimicrobial:

Some period underwear incorporates natural antimicrobial properties from bamboo or silver ions, preventing bacterial growth and odour. These can contain PFAS, so look for brands like fluxies that use natural materials with naturally occurring antimicrobial properties like Modal. 

Avoid Chemicals:

Choose underwear free from harmful chemicals and synthetic fragrances.

Hypoallergenic Materials

Sensitive Skin:

If you have sensitive skin, opt for hypoallergenic materials like Organic Cotton.

Allergy Testing:

Make sure to look for certifications or product descriptions confirming that the underwear is safe for sensitive skin. All our period pants are OEKO-Tex certified, ensuring they're gentle on skin. But remember to check for similar assurances from other brands before making a purchase!

Regular Replacement

Signs of Wear:

Replace your period underwear if you notice a decrease in absorbency, elasticity loss, or visible wear and tear. We offer a 60-day money back guarantee on your first pair of period pants, so you can try them risk-free.


Maintaining hygiene by replacing worn-out pairs ensures continued protection and comfort.

Period underwear revolutionises menstrual care, providing comfort, sustainability, and cost-effectiveness. Understanding absorbency levels, fabric options, care tips, and the environmental and health benefits empowers you to choose what fits your needs best. Embrace the convenience and peace of mind that period underwear offers, taking a step toward a more sustainable and comfortable menstrual journey.

Frequently Asked Questions (FAQ)

Q1: Can I wear period underwear overnight?

Yes, period underwear designed for heavy flow or overnight protection can be worn overnight. They provide extra coverage and high absorbency to prevent leaks.

Q2: How many pairs of period underwear do I need?

The number of pairs you need depends on your flow and how often you plan to wash them. On average, having 5-7 pairs can cover an entire menstrual cycle.

Q3: Can period pants replace tampons and pads completely?

For many people, yes. Period underwear with the right absorbency level can completely replace traditional menstrual products. However, some people prefer to use them as a backup or on lighter days.

Q4: Is period underwear bulky?

No, our period underwear is designed to be slim and discreet while still providing excellent absorbency.

Q5: Can I use fabric softener on my period underwear?

No, fabric softeners can reduce the absorbency of period underwear. It’s best to use a mild, fragrance-free detergent instead.