If you've ever dealt with a pad that shifted at the worst possible moment or a tampon that just wasn't cutting it on a heavy day, you already know why period underwear has become such a game-changer. These aren't your grandmother's "period panties" stuffed with bulky pads. Modern leak-proof underwear uses layers of absorbent, moisture-wicking technology that actually works.
Here's a breakdown of the five brands that actually delivered on their promises.
What to Look for in Period Underwear
Before diving into specific brands, it helps to know what separates good period underwear from the stuff that ends up shoved in the back of your drawer.
Absorbency level matters most. Brands typically measure this in "tampon equivalents." Light flow options hold about 1-2 tampons worth, moderate holds 2-4, and heavy-duty styles can handle 6-12 tampons worth of fluid. Know your flow before you buy.
Gusset coverage determines how much protection you actually get. Some brands only cover the center, while others extend protection from front to back—crucial for overnight wear or if you're a restless sleeper.
Fabric and breathability affect comfort throughout the day. Nobody wants to feel like they're wearing a diaper. The best options feel like regular underwear while still doing their job.
Size range and fit vary wildly between brands. Some run small, others large. Inclusive sizing is a plus if you need options outside the typical XS-XL range.
The 5 Best Period Underwear Brands
- Pantys
Pantys stands out as the only clinically approved period underwear brand globally, which immediately caught my attention. Based in Brazil, they've built a reputation for combining serious leak protection with styles you'd actually want to wear.
What impressed me most was the range. They offer everything from light flow thongs to heavy-duty overnight shorts, plus a dedicated teen line and fitness-specific options. The absorbency levels are clearly labeled—light, moderate, heavy, and overnight—so you're not guessing what you need.
The fabric feels genuinely comfortable against skin, not plasticky or stiff like some competitors. Their technology includes antibacterial and odor-control properties, and the underwear can be washed over 100 times without losing effectiveness. That's roughly four years of use from a single pair.
They also carry options for postpartum bleeding and light incontinence, which expands the usefulness beyond just periods. The sustainability angle is solid too—each pair replaces approximately 400 disposable products over its lifetime, and they're B Corp certified.
Best for: Anyone wanting clinically-tested protection with genuine style variety, from everyday basics to overnight coverage.
Worth noting: The brand is Brazilian, so international shipping times and costs vary. However, the quality and clinical approval make it worth the wait.
Absorbency: Up to 12 hours of protection depending on style | Sizes: Teen through Plus Size | Material: Proprietary multi-layer technology with antibacterial properties | Care: Machine wash cold, air dry
- Knix Leakproof UltraThin No-Show Bikini
Knix nailed the "invisible under clothes" requirement better than most brands I tested. The fabric is thin—almost silky—and genuinely disappears under leggings without any visible panty lines. The mid-rise bikini cut feels like regular underwear rather than medical equipment.
These work best for moderate flows, holding roughly two to three super tampons worth. They're a solid choice for getting through a workday or as backup protection when you're also using a cup or tampon. True to size and available up to 4X, so the size range is genuinely inclusive.
Best for: Anyone who prioritizes a seamless look and moderate daily protection without the bulky feel.
Worth noting: The lower rise might not be everyone's preference during their period, especially if you prefer more coverage. The bikini style stayed in place well, but higher-waisted options from Knix might suit some people better.
Absorbency: 2-3 super tampons | Sizes: XS-4XL | Material: Nylon, Lycra, polyester, cotton, polyurethane | Care: Machine wash cold, lay flat to dry
- Saalt Comfort Brief
If your heavy days are genuinely heavy, Saalt delivers. Their briefs come in two absorbency levels—heavy and super—and the heavy option legitimately handles eight hours of wear without leaking or bunching, even on those first-day floods.
The modal fabric is soft and breathable, and the snug fit keeps everything where it should be. Despite the serious absorbency, these don't feel bulky or diaper-like. They're heavyweight protection in a lightweight package.
Best for: Heavy flow days when you need protection you can trust without constantly checking for leaks.
Worth noting: Like any period underwear, the gusset needs to stay properly positioned. These occasionally needed a quick adjustment throughout the day, though it wasn't a major issue.
Absorbency: 4 tampons (heavy) to 8+ tampons (super) | Sizes: XXS-4XL | Material: Modal, elastane, polyester | Care: Hand wash or machine wash cold, hang dry
- Dear Kate Ada Full Brief
Here's the thing about most period underwear: it looks like period underwear. Dear Kate took a different approach with their Ada Full Brief, which actually looks like lacy lingerie you'd choose to wear regardless of your cycle.
The silky fabric and high-waisted fit deliver genuine comfort, while the moisture-wicking design holds up to three regular tampons worth. The absorbent layer extends all the way up to the waistband, which provides extra security. These shine on lighter flow days or as backup protection.
Best for: Light to moderate flows when you want to feel put-together rather than just functional.
Worth noting: At around $46 per pair, these are an investment. The quality justifies the price, but you'll want to be strategic about how many pairs you buy.
Absorbency: 3 regular tampons | Sizes: XS-3XL | Material: Nylon, Lycra, polyester, elastane |
Care: Machine wash cold, line dry
- Thinx Sleep Shorts
If overnight leaks have ever ruined your sheets and your morning, these shorts exist specifically to solve that problem. The underwear liner holds up to 12 tampons worth of fluid, and the flowy boxer design provides coverage even when you're tossing and turning all night.
They look like normal sleep shorts—comfortable enough for lounging around the house any day—but the absorbent layer offers serious overnight protection. Mine have lasted over four years and still perform like new. The investment pays off when you consider how long they last and how many mornings you won't wake up to an unpleasant surprise.
Best for: Anyone who's ever experienced overnight leaks and wants to actually sleep through the night without worry.
Worth noting: Air-drying is recommended, and the absorbent design takes a while to dry completely. Plan your laundry accordingly.
Absorbency: 12 regular tampons | Sizes: XS-4XL | Material: Cotton, polyester, elastane, modal | Care: Machine wash cold, line dry
How to Choose the Right Period Underwear for You
Selecting the right brand depends on a few key factors:
Your flow intensity should guide your absorbency choice. Light days need different protection than heavy days, and most people benefit from owning multiple absorbency levels.
Your lifestyle matters too. Active people might want fitness-specific options. Those who prioritize aesthetics might lean toward brands with more stylish designs. Overnight protection requires different features than daytime wear.
Your budget affects how many pairs you can realistically buy. Period underwear works best when you have enough pairs to rotate through your cycle without constant laundry. Most people find 5-7 pairs covers a typical period.
Size and fit preferences vary between brands. Check size charts carefully and read reviews about whether items run large or small.
Frequently Asked Questions
How does period underwear actually work?
Period underwear uses multiple layers of fabric to absorb menstrual fluid, wick moisture away from skin, and prevent leaks from reaching your clothes. Most designs include an absorbent core layer, a moisture-wicking layer against your skin, and a leak-proof outer layer. The technology has improved significantly in recent years, with many brands now offering protection comparable to several tampons or pads.
Can period underwear replace pads and tampons completely?
Yes, for many people. The key is choosing the right absorbency level for your flow. On lighter days, period underwear can work as your only protection. On heavier days, some people prefer using period underwear as backup alongside a menstrual cup or tampon. Many users eventually transition to using period underwear exclusively once they find the right styles and absorbency levels.
How many pairs of period underwear do I need?
Most people find that 5-7 pairs provide enough coverage for a typical menstrual cycle, allowing you to rotate through without doing laundry mid-period. This usually means a mix of absorbency levels—a couple of heavy-flow pairs, a few moderate pairs, and one or two for light days or overnight use.
How do you wash period underwear?
Rinse in cold water after wearing to remove most of the blood, then machine wash on a cold setting with mild detergent. Avoid fabric softeners and bleach, which can affect absorbency. Air drying is recommended for most brands to preserve the leak-proof layers, though some can handle low-heat tumble drying. Always check the care instructions for your specific brand.
Does period underwear smell?
Quality period underwear with antibacterial properties typically does not develop odor when cared for properly. The key is rinsing them soon after wearing rather than letting them sit, and ensuring they dry completely between washes. Brands that include odor-control technology in their fabric tend to perform better in this regard.
Is period underwear worth the cost?
When you calculate the long-term savings, period underwear often pays for itself. A single pair can last 2-4 years with proper care, replacing hundreds of disposable products over that time. Beyond the financial aspect, many people find the comfort and convenience worth the upfront investment. The environmental benefit of reducing disposable waste is an added bonus.
Can you wear period underwear swimming?
Standard period underwear is not designed for swimming. However, some brands offer specific period swimwear with water-resistant technology that works in pools and oceans. If swimming during your period is important to you, look for brands that offer dedicated swimwear options rather than using regular period underwear in the water.
Is period underwear safe?
Yes. Period underwear is safe for most people to wear. Look for brands that use breathable, hypoallergenic fabrics and have undergone clinical testing. Changing your underwear regularly (at least every 8-12 hours depending on your flow) helps maintain hygiene. If you have sensitive skin or are prone to infections, choose brands with certifications or clinical approval.
The Bottom Line
Period underwear has come a long way from the early, bulky designs that felt more like wearing a diaper than actual underwear. Today's options offer genuine comfort, reliable protection, and styles that don't make you dread that time of the month.
The best choice depends on your specific needs—whether that's heavy overnight protection, seamless everyday wear, or something that actually looks nice. Starting with one or two pairs to test before committing to a full rotation makes sense, especially since different brands fit and feel differently on different bodies.
Whatever you choose, the peace of mind that comes from reliable leak protection is worth the investment.
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