Best Women’s Running Underwear 2026: No More Chafing
The short answer
Start with a smooth, quick-drying pair that stays put
The Lululemon UnderEase Mid-Rise Bikini is the easiest place to start if you want soft coverage, flat seams, and a waistband that should sit quietly under running shorts. Choose Runderwear when you want a running-specific design and can find your size. Reebok is the practical multipack, Voenxe is the no-show thong, Smartwool adds merino for temperature control, and Saalt adds leak protection.
Fit matters more than the logo. A great pair should stay dry, avoid thick seams, and move with you without riding up. You can find more seasonal kit in our running clothing and gear guides.
Affiliate disclosure: Running Gear Lab may earn a commission if you buy through some links on this page. That does not change what you pay. Product availability, colours, and prices can change.
Updated September 2026: Product specifications, shopping links, and Canadian availability were rechecked for this update.
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Best women’s running underwear at a glance
Best place to start
Lululemon UnderEase
Soft mid-rise coverage with flat seams and a smooth waistband.
Running-specific
Runderwear Hipster
Light, low-rise, and made for running, but Canadian stock is limited.
Best budget multipack
Reebok Seamless Hipster
A simple seamless option when you want several pairs without a premium price.
Best no-show thong
Voenxe Seamless Thong
Minimal coverage for runners who already know they prefer a thong.
Best merino blend
Smartwool Intraknit
Breathable mesh zones and a merino blend for long or changeable days.
Best leak protection
Saalt Leakproof Brief
A smoother period-underwear option for backup protection on active days.
How we chose these pairs
This update checks the cuts, fabrics, seam placement, care instructions, and current availability of the products already featured in this guide. We gave more weight to details that matter once you start sweating:
- Seams and edges: flat or bonded areas are less likely to rub than bulky stitching.
- Moisture control: quick-drying synthetic, modal, or merino blends are safer bets than everyday cotton on long, warm runs.
- Fit: the waistband should stay level and the leg openings should not cut in or creep upward.
- Real buying limits: we flag stock problems and avoid fixed prices because both change often.
We do not assign pretend lab scores or claim every pair was run-tested for the same number of miles. Product specifications tell us what a pair is designed to do, but your body shape, shorts, weather, and distance decide whether the fit works for you.
The six best options
Best place to start
Lululemon UnderEase Mid-Rise Bikini
UnderEase is a sensible first try if you dislike stiff elastic or obvious seams. The mid-rise bikini sits below many mid-rise tights and shorts, while the waistband is designed to lie smooth instead of digging in.
- Best for: everyday training and runners who want more coverage
- Fabric: 88% modal and 12% Lycra elastane
- Good detail: flat, chafe-resistant seams and quick-drying stretch fabric
- Watch for: it is designed as casual underwear, so test it on a short run before race day
The fabric should feel softer than a typical performance synthetic. That makes it comfortable, but it may not feel as stripped-down as a dedicated racing brief.
Best running-specific design
Runderwear Women’s Running Hipster
Runderwear starts with running rather than everyday wear. The hipster has a low-rise cut, light fabric, and a smooth construction intended to reduce rubbing under tights or shorts.
- Best for: runners who want a dedicated performance brief
- Fit: low rise with hipster coverage
- Good detail: lightweight, breathable recycled fabric in the current white version
- Watch for: the Canadian product page was sold out when this guide was updated
This remains a strong design to watch, but it is not helpful to call it the easiest buy while sizes are unavailable. Check stock before deciding.
Best budget multipack
Reebok Seamless Hipster Briefs
Reebok’s seamless hipsters make sense when you want enough pairs for a training week without buying each one separately. They are often sold in multipacks, and the simple cut works under shorts, tights, or gym clothes.
- Best for: easy runs, gym sessions, and building a practical rotation
- Fit: hipster coverage with a seamless feel
- Good detail: multipacks usually cost less per pair than premium singles
- Watch for: pack contents and fabric blends can vary by listing
Check the listing photos and fabric label before buying. Discount stores such as Winners or Marshalls may also carry Reebok athletic underwear, but stock is unpredictable.
Best no-show thong
Voenxe Seamless Women’s Thongs
A thong is not automatically better for running, but it can solve visible lines and bunching for runners who already like this cut. Voenxe uses thin, stretchy fabric with bonded-looking edges that sit flat under leggings.
- Best for: a no-show look under fitted tights
- Fit: minimal thong coverage
- Good detail: smooth edges and lightweight stretch
- Watch for: the wrong size can shift or rub, especially on longer runs
Do not make race day your first test. Wear a new thong on a short, familiar route and check how it feels once the fabric is damp.
Best merino blend
Smartwool Women’s Intraknit Bikini
The Intraknit Bikini blends merino wool with lyocell, nylon, and elastane. Merino helps manage temperature and odour, while mesh zones add airflow. This is the pair to consider for long outings, travel, or weather that changes through the day.
- Best for: long days, cooler starts, and runners who like merino
- Fabric: 42% merino wool, 38% lyocell, 12% nylon, and 8% elastane
- Good detail: flatlock seams, mesh zones, and moderate bikini coverage
- Watch for: it costs more than a basic synthetic multipack
Wash it cold on a gentle cycle. Merino blends last longer when they are not cooked in a hot dryer.
Best leak protection
Saalt Leakproof Seamless Brief
Saalt’s seamless brief is for period days when standard running underwear does not give enough backup. The smooth design is less bulky than many traditional period briefs and is made to sit quietly under clothing.
- Best for: period days or backup leak protection
- Fit: seamless brief with fuller coverage
- Good detail: smooth fabric that is designed to disappear under clothing
- Watch for: absorbent underwear feels different from a light running brief, so test it before a long run
Follow the care instructions closely: rinse cold, machine wash cold, and hang dry. Skip fabric softener and bleach because they can harm the absorbent layers.
How to choose running underwear that does not chafe
Start with fit, not fabric claims
A waistband that rolls or a leg opening that creeps up will still annoy you, even if the fabric is excellent. The pair should feel close to the body without pinching. Move through a squat and a few high knees before removing the tags.
Check your shorts before buying more underwear
Many running shorts already have a built-in liner. If that liner fits well, you may not need underwear at all. If it rubs, traps sweat, or does not give enough coverage, try a liner-free short with one of the pairs above. Our Best Running Shorts for Women guide separates the options that stay put from the ones that tend to ride up.
Choose the cut you already trust
A bikini or hipster gives more coverage and is the safest starting point for most runners. A thong can work if you already wear one comfortably, but changing cuts right before a long run is asking for trouble. Period underwear adds useful protection, though it will feel warmer and more substantial than a thin brief.
Treat repeat hotspots separately
If the underwear fits but you still rub in the same spot, use a small amount of anti-chafe balm before the run. The Best Anti-Chafing Products for Runners guide explains which formats work for thighs, waistbands, feet, and sensitive areas.
Simple test
Try every new pair for 20 to 30 minutes close to home. If it shifts while dry, it will probably feel worse once it is wet. Save long runs and races for the pair that has already earned your trust.
What to wear with them
Underwear is only one layer. Heat, humidity, rain, and run length change what feels comfortable over it. Use the running outfit calculator to build the rest of your kit around the day’s conditions.
Women’s running underwear FAQ
What type of underwear is best for running?
A close-fitting bikini or hipster made from quick-drying fabric is the best starting point for most runners. Look for flat seams, soft edges, and a waistband that stays level. The right cut is the one that does not move once you start sweating.
Should I wear underwear under lined running shorts?
You do not have to. A good built-in liner is meant to replace underwear. Add a separate pair only if the liner feels rough, gives too little coverage, or does not manage moisture well for you.
Is cotton underwear bad for running?
Cotton can be fine for a short, easy run in cool weather, but it holds moisture longer than technical fabric. On warm or long runs, wet cotton is more likely to feel heavy and rub.
Can a thong work for running?
Yes, if you already find thongs comfortable and the size stays put. Choose a smooth, stretchy pair and test it on a short run first. A thong that shifts can create a very specific hotspot.
How many pairs of running underwear do I need?
Three to five pairs cover most training weeks if you wash regularly. Start with one pair first. Once you know the fit works, buying enough for your normal run schedule makes sense.
Can I run in period underwear?
Yes. Choose a secure fit and the absorbency you need, then test it on an easy run. Period underwear is usually warmer and thicker than a standard brief, so comfort can change with distance and temperature.
