10 Best Period Underwear (That Are Also HSA/FSA Eligible)

Period underwear has quickly become one of the most popular reusable menstrual care products because it offers comfortable, leak-resistant protection while helping reduce waste and long-term period care costs.

They don’t have to fully replace tampons and pads either. In some cases, period underwear can provide additional protection, overnight comfort, or simply give you peace of mind. Even if you don’t plan on fully replacing tampons and pads, period underwear can make a great addition to your menstrual care routine.

Many period and menstrual care products are also eligible expenses under Health Savings Accounts (HSAs) and Flexible Spending Accounts (FSAs), which means you may be able to use pre-tax healthcare dollars to purchase them.

This guide to choosing the best pair for you will cover these topics to help you make your decision:

• How does period underwear work and what are the benefits of using it?
• 10 benefits of using period underwear over pads, tampons, cups, and other menstrual products
• How much money can one pair of period underwear save you?
• How to choose the best period underwear for your needs
• 10 best period underwear for a variety of health concerns, with different fits
• Is period underwear HSA or FSA eligible?
• 8 tips to extend the life of your period underwear

Before we get to where and how to buy HSA/FSA eligible period underwear, let’s start by looking at how period underwear works and what the core benefits are.

How does period underwear work and what are the benefits of using it?

Period underwear offers a reusable alternative to traditional menstrual products like pads and tampons, while still providing absorbent leak protection throughout your cycle. As these products become more popular, many people are curious about how they actually work, what benefits they offer, and whether they’re worth the investment.

How long does period underwear last?

Most high-quality period underwear lasts between 2 and 5 years with proper care. The lifespan depends on the brand, fabric quality, how often you wear them, and how carefully you wash and dry them.

The absorbent layers inside period underwear naturally wear down over time. After repeated washes, the fabric may become less effective at absorbing fluid or preventing leaks. As with normal underwear, elastic bands and seams can also stretch out with regular use.

Your flow can also affect longevity. Heavier flows may put more strain on absorbent layers over time compared to occasional light spotting use.

How often should you buy new period underwear?

Most people should plan to replace period underwear every 1 to 3 years, depending on usage and care habits. If you use period underwear heavily throughout every cycle, you may need to replace certain pairs sooner.

There’s no universal replacement schedule because everyone’s menstrual routine looks different. Some people only use period underwear as backup protection, while others wear it exclusively during their period.

A good approach is to evaluate your underwear at the end of each year and look for signs of wear or reduced absorbency. You may want to buy new period underwear more often if you use the same pair every cycle without rotating, you frequently wear heavy-flow styles overnight, you accidentally machine dry them on high heat, you notice leaks developing, and the fit changes over time.

Many people find it helpful to own enough pairs for at least 2 to 3 days of wear before washing. That usually means having between 4 and 8 pairs, depending on your flow and laundry schedule. Replacing one or two pairs at a time instead of your entire collection can help spread out costs and keep your period care routine consistent.

Proper washing and maintenance also play a major role in how frequently you’ll need to replace your period underwear, so caring for them correctly can save money over time.

What’s the best way to wash period underwear?

The best way to wash period underwear is to rinse it in cold water after use, then machine wash on a gentle cycle without fabric softener or bleach. Air drying is usually the safest option to help preserve the absorbent layers.

Most brands include specific washing instructions, but the general care process stays fairly similar across products.

Here’s a simple step-by-step routine for washing period underwear:

1. Rinse after wearing: Rinse the underwear in cold water until the water runs mostly clear. This helps remove excess blood before washing.
2. Place in a laundry bag: Using a mesh laundry bag can help protect delicate fabrics and elastic during the wash cycle.
3. Wash in cold water: Choose a gentle cycle with mild detergent. Hot water can damage absorbent materials and shorten the lifespan of the underwear.
4. Avoid fabric softener and bleach: Fabric softeners can coat absorbent fibers and reduce performance. Bleach may weaken fabrics and elastic over time.
5. Air dry when possible: Lay flat or hang dry. High heat from dryers can damage leak-resistant layers and reduce absorbency.

Some people prefer hand washing period underwear, especially for delicate fabrics, but most modern brands are machine washable.

You should also avoid ironing or dry cleaning period underwear because heat and chemicals can damage the specialized layers inside the fabric.

If odor becomes an issue, a small amount of white vinegar during washing may help remove buildup naturally without damaging absorbency.

Proper care matters because the technology inside period underwear depends on specialized fabrics staying intact. Consistent washing habits can help preserve leak protection and extend the usable life of each pair. The easier the care routine feels, the more likely you are to stick with reusable menstrual products long term.

10 benefits of using period underwear over pads, tampons, cups, and other menstrual products

Period underwear has become increasingly popular because it offers a reusable, comfortable, and low-maintenance alternative to traditional menstrual products. While pads, tampons, and menstrual cups still work well for many people, period underwear provides several unique benefits that can make managing your cycle easier and more convenient.

Here are some of the biggest advantages of using period underwear:

1. Improved comfort — Period underwear often feels more like regular underwear than bulky pads or internal menstrual products, which can make all-day wear more comfortable.
2. Cost savings over time — Although the upfront cost may be higher (especially if you plan on buying multiple pairs to start), reusable period underwear can replace hundreds of disposable pads or tampons over its lifespan, helping reduce long-term menstrual care expenses.
3. HSA/FSA eligible — Many period underwear products qualify as HSA- and FSA-eligible menstrual care expenses, which means you may be able to use pre-tax healthcare dollars to purchase them through online marketplaces like Flex.
4. Less skin irritation — Soft, breathable fabrics may help reduce chafing, dryness, and irritation that some people experience with disposable pads or tampons.
5. Fewer added chemicals — Many period underwear brands focus on reusable fabric construction without fragrances or unnecessary additives commonly found in some disposable menstrual products.
6. Eco-friendly and sustainable — Reusable period underwear helps reduce waste by replacing disposable pads, liners, and tampons that would otherwise be thrown away each month.
7. Leak protection — Many period underwear styles include built-in leak-resistant layers and extended coverage areas designed to help prevent visible leaks during the day or overnight.
8. Lower risk of toxic shock syndrome (TSS) — Because period underwear is worn externally, it does not carry the same TSS concerns associated with tampon use.
9. Versatility and convenience — Period underwear can work for light spotting, heavy flow days, overnight protection, workouts, travel, postpartum recovery, and backup protection alongside other menstrual products.
10. Already wearing it — Instead of needing to carry pads or tampons everywhere you go, you’re already wearing period underwear, so you’re already prepared for what comes your way. That can make unexpected periods, long workdays, travel, or busy schedules feel much less stressful.

As more people look for reusable menstrual care options, period underwear continues to stand out as a flexible and cost-effective choice for everyday period management.

Whether you’re looking exclusively for menstrual health products or you want other women’s health products, check out the Flex Marketplace for HSA/FSA eligible women’s health products. You’ll be able to buy HSA/FSA eligible period underwear fast and conveniently with your HSA/FSA payment cards.

How much money can one pair of period underwear save you?

One pair of period underwear can potentially replace hundreds of disposable pads or tampons over its lifespan, which may save you anywhere from $50 to $200 or more over time depending on your menstrual routine.

Most period underwear brands estimate their products last between 40 and 60 washes, though many users report getting several years of use with proper care. If you wear one pair during every cycle, that single pair could replace dozens of disposable products each year.

For example:

• A medium-absorbency pair may replace about 2 to 5 regular tampons or pads per wear
• If worn 50 times over its lifespan, one pair could replace roughly 100 to 250 disposable products
• Disposable pads and tampons often cost between $0.20 and $0.50 each depending on brand and type

That means one pair of reusable period underwear could offset approximately:

• $20 to $125 in disposable product costs over time
• Even more if you typically buy premium organic or specialty menstrual products

The savings can add up faster for people with heavier flows or longer cycles who normally use more disposable products each month. Period underwear may also help you avoid emergency purchases when traveling or during unexpected cycles, which can sometimes cost more at convenience stores or pharmacies.

If you build a small rotation of several pairs, you may reduce your need for disposable menstrual products almost entirely. Buying just 5 pairs would cost you $125 dollars. If you had to do the wash twice during your period, you’d wash each pair 24 times during the year. At an average of 50 washes per pair, these 5 pairs would easily last you 2 years. Even if each period costs you $10 in tampons and pads, you’d end up spending $120 in just one year.

Your actual savings will depend on your flow, how frequently you wash them, and the overall wear they receive, but the right rotation of reusable pairs can save you a meaningful amount over the life of each product.

How to choose the best period underwear for your needs

Choosing the best period underwear starts with understanding your flow, comfort preferences, and how you plan to use them throughout your cycle. With so many absorbency levels, styles, and specialty features now available, comparing the right factors can help you find period underwear that feels comfortable, performs reliably, and fits your everyday routine.

What types of period underwear exist?

Period underwear comes in a range of styles and fits, but the most common type breakdown is based largely on absorbency levels.

1. Light & Liner: These styles are designed for spotting, very light flow days, or backup protection with tampons or menstrual cups.
2. Moderate: Moderate absorbency period underwear works well for average daytime flow and can often replace several pads or tampons on medium-flow days.
3. Heavy: Heavy absorbency styles provide extra leak protection for heavier periods and typically include thicker absorbent layers.
4. Overnight: Overnight period underwear offers extended front and back coverage to help prevent leaks while sleeping.
5. Sport & Activewear: Athletic period underwear uses breathable, moisture-wicking fabrics designed to stay comfortable during workouts and physical activity.

How to evaluate the features of a pair of period underwear

Not all period underwear is designed the same way, so comparing the right features can help you find a pair that matches your flow, comfort preferences, and lifestyle. Here are the most important things to evaluate before buying.

1. Absorbency level: Choose a pair with enough absorbency for your flow, whether you need light spotting protection or heavy overnight coverage. You may want different pairs for different days of your period.
2. Leak protection coverage: Look for styles with extended front, back, or side coverage if you want extra protection against leaks. You can also cover some of these gaps by occasionally using tampons or pads.
3. Fabric and comfort: Soft, breathable fabrics like cotton or moisture-wicking blends usually feel more comfortable for all-day wear.
4. Non-toxic, PFAS-free materials: Some period underwear has historically been made with PFAS (per- and polyfluoroalkyl substances, sometimes called “forever chemicals”). If material safety matters to you, look for brands that advertise PFAS-free construction or carry third-party certifications like OEKO-TEX STANDARD 100.
5. Fit and sizing: A snug but comfortable fit helps prevent leaks and keeps the absorbent layers close to your body. It not only enhances comfort, but ensures the product works as intended.
6. Odor control: Many brands include moisture-wicking or odor-resistant materials to help you stay fresh throughout the day, supporting hygiene and increasing comfort.
7. Washability: The best period underwear should be easy to rinse, machine wash, and maintain without complicated care instructions.
8. Durability: High-quality pairs with reinforced seams and strong elastic often last longer and provide better long-term value. Period underwear needs to hold up to regular wear and routine cleaning.
9. Style and cut: Period underwear comes in styles like bikini, brief, thong, boyshort, and high-waisted fits to match different comfort preferences and outfits.

Material safety is worth a closer look. Period underwear sits against sensitive skin for hours at a time, and past testing has found PFAS in some products, so choosing brands that are transparent about PFAS-free construction and certifications gives you extra peace of mind alongside comfort and performance.

It’s all about finding the right fit for your needs. That could mean five identical pairs or a mix of light, medium, and heavy pairs that you wear at different times. Ultimately, it’s about balancing performance, comfort, and confidence.

What do you gain as you spend more money on a pair of period underwear?

More expensive period underwear often includes higher-quality materials, stronger absorbency technology, and features designed for better comfort and durability. While budget-friendly options can still work well, premium pairs may feel more comfortable and last longer with regular use.

As prices increase, you may notice benefits like:

• Softer and more breathable fabrics
• Better leak protection and absorbency
• Thinner, less bulky designs
• Extended overnight coverage
• Stronger odor-control technology
• More durable stitching and elastic
• Better fit and size inclusivity
• Specialty features like swimwear, shapewear, or heated fabric

Premium brands also tend to offer more style options, including athletic fits, seamless designs, and underwear that feels closer to regular everyday clothing.

That said, the best period underwear isn’t always the most expensive. The right option depends on your flow, comfort preferences, and how often you plan to wear and wash them. Many affordable brands still provide reliable protection for everyday use.

10 best period underwear for a variety of health concerns, with different fits

Below are 10 of the best period underwear options across a range of needs — from everyday comfort and overnight protection to swimming, shapewear, and therapeutic warmth. Where possible, we’ve highlighted brands available through the Flex Marketplace so you can shop HSA/FSA eligible options directly.

1. Best for comfort & versatility: Shorty Jim Jams by Tampon Tribe

Cost: $35 - $55

Shorty Jim Jams by Tampon Tribe are designed for softness, flexibility, and everyday comfort. Their relaxed short-style fit works well for sleeping, lounging, working from home, or wearing during lighter flow days when comfort matters most. They’re also a versatile option for people who prefer more coverage than traditional bikini or brief styles.

2. Best for additional protection: The Extra Coverage High Waisted Period by The Period Company

Cost: $20 - $40

The Extra Coverage High Waisted Period underwear is designed for heavier flow days and people who want more leak-resistant coverage throughout the day or overnight. The extended gusset protection adds absorbency further toward the front and back, which can help reduce leaks while sleeping, sitting for long periods, or traveling.

3. Best for soft shapewear: High Luxe by Tampon Tribe

Cost: $35 - $55

The High Luxe by Tampon Tribe combines absorbent protection with gentle shaping support, making it a good option if you want smoother coverage under dresses, workwear, or fitted clothing. The high-waisted fit offers light compression without feeling overly restrictive, while still maintaining the comfort and flexibility you expect from reusable period underwear.

4. Best for overnight protection: The Sleeper by The Period Company

Cost: $25 - $40

The Sleeper Period underwear is specifically designed for overnight use and extended wear. It features more absorbent coverage through the front and back to help reduce leaks while sleeping, which can provide extra peace of mind during heavier flow nights. The soft fabric and fuller coverage also help make overnight wear feel more comfortable and secure.

5. Best for bloating & heavy cramping: The Boxer Brief by Monthly

Cost: $40 - $60

The Boxer Brief by Monthly offers soft full-coverage support that can feel especially comfortable during bloating and cramping. The longer boxer-style fit helps reduce friction and creates a more relaxed feel around the waist and hips compared to tighter underwear cuts. Many people also prefer this style for overnight wear because it provides extra coverage and a more secure fit during heavier flow days.

6. Best for discreet coverage: The Thong Period by The Period Company

Cost: $15 - $30

The SportyStretch Thong and Microfiber Light Absorbency Thong are designed for lighter flow days, spotting, and situations where you want discreet protection under fitted clothing. These styles work especially well for formal events, office attire, leggings, or dresses where visible underwear lines are a concern. The SportyStretch option offers a more athletic feel, while the microfiber version provides a smoother, softer finish under clothing.

7. Best for machine washing: Washable Period Underwear by Lola

Cost: $25 - $40

The Washable Period Underwear by Lola is designed for people who want a straightforward, low-maintenance reusable period care routine. These machine-washable styles focus on convenience and everyday wearability, making them a good option for first-time period underwear users or anyone looking for simpler product care.

8. Best for swimming & summer: The Swim by The Period Company

Cost: $30 - $50

The Swim High Waisted and Swim Bikini by The Period Company are designed for swimming, beach days, vacations, and other warm-weather activities where traditional period products may feel less convenient. The high-waisted style offers more coverage and support, while the bikini cut provides a more minimal, versatile fit. Both options are designed to help you feel more comfortable and confident in and around water.

9. Best for therapeutic warmth: Heated Shorts by Sundaze

Cost: $100 - $150

The Sundaze Heated Shorts combine wearable warmth with soft, comfortable coverage to help support relaxation during cramping, pelvic discomfort, and lower back tension. Unlike traditional heating pads, these heated shorts allow you to move around more freely while still getting therapeutic warmth throughout your lower abdomen and hips. They work especially well for lounging, working from home, sleeping, or recovering during heavier period days.

10. Best pairing for your period underwear: The Reusable Pad by The Period Company

Cost: $20 - $60

The Reusable Pad Bundle for Heavy Flows and Reusable Pantyliner Bundle for Medium Flows work well alongside period underwear when you want extra absorbency or backup protection. Reusable pads may help extend wear time during heavier days, while reusable pantyliners are useful for lighter flow, spotting, or added security during long workdays and travel.

Is period underwear HSA or FSA eligible?

Yes, many types of period underwear are HSA- and FSA-eligible because menstrual care products qualify as eligible medical expenses under current IRS guidelines. That means you may be able to use funds from your Health Savings Account (HSA) or Flexible Spending Account (FSA) to purchase qualifying period underwear, reusable pads, liners, and other menstrual products.

In some cases, period underwear that serves a dual purpose may need a Letter of Medical Necessity (LMN) to qualify. Typically though, period underwear automatically qualifies as a menstrual care product.

Eligibility can vary by retailer and product type, so it’s helpful to shop through platforms like the Flex Marketplace, which makes it easier to find HSA and FSA-eligible menstrual care products online. Many merchants let you buy directly with your HSA/FSA payment card instead of paying out of pocket.

8 tips to extend the life of your period underwear

Period underwear can last for years with proper care, but washing and storing it incorrectly can shorten its lifespan and reduce absorbency. Following a few simple maintenance habits can help you get better performance, prevent leaks, and save more money over time.

1. Rinse them after use— Rinsing period underwear in cold water soon after wearing helps remove excess blood and prevents buildup in the absorbent layers.
2. Wash with cold water— Cold water is gentler on absorbent fabrics and helps preserve the leak-resistant technology inside the underwear.
3. Skip fabric softener— Fabric softeners can coat absorbent fibers and make period underwear less effective over time.
4. Avoid bleach— Bleach may damage elastic, weaken fabric, and reduce the lifespan of the absorbent lining.
5. Air dry whenever possible— High dryer heat can break down leak-proof layers and shorten the life of your underwear.
6. Use a gentle detergent— Mild detergents help clean the fabric without causing unnecessary wear or irritation.
7. Rotate between multiple pairs— Owning several pairs reduces how often each one gets washed and can help them last longer.
8. Follow the brand’s care instructions— Different materials and absorbency technologies may require specific washing or drying recommendations.

Taking proper care of your period underwear can help maintain absorbency, improve comfort, and extend the value of your purchase over time.

In summary

Period underwear offers a comfortable, reusable, and increasingly popular alternative to traditional menstrual products, with options available for everything from light spotting to heavy overnight protection. Whether you prioritize comfort, leak prevention, sustainability, or convenience, there are now period underwear styles designed to fit almost every lifestyle and menstruation concern.

As you compare products, pay close attention to absorbency, fit, fabric quality, and care instructions so you can choose a pair that works well for your flow and daily routine. Investing in high-quality period underwear may also help reduce long-term menstrual care costs, especially since many products qualify as HSA- and FSA-eligible expenses.

If you’re ready to shop for period underwear and other eligible menstrual care products, the Flex Marketplace makes it easy to browse HSA- and FSA-eligible wellness products from a wide range of brands in one place.