Reviews You Can Rely On

Best Travel Underwear for Women of 2021

We buy and test the top options from Smartwool, ExOfficio, Patagonia, and REI to find the best
Testing women's travel underwear on a trip to the southern hemisphere.
Photo: Lauren DeLaunay
Tuesday July 13, 2021
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Our women's travel underwear experts researched 50+ of the best options available in 2021 and bought 13 of the finest to test side-by-side. We've used these skivvies all over the world, from Argentina to Cuba. We explored, hiked, climbed, trekked, went to the gym, and wore them while on planes, trains, and automobiles. A good pair of underpants fit well, are comfortable, and easy to wash by hand. We evaluated each comparatively based on these metrics, in addition to their fabric and construction. If you're seeking a reliable pair of travel underwear to keep you comfortable, clean, and protected on any adventure, our hands-on review will help you find them.

Top 13 Product Ratings

Displaying 1 - 5 of 13
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Awards   Editors' Choice Award Top Pick Award  
Price $18.00 at Backcountry
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$14.95 at REICheck Price at REI
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$22.75 at Backcountry
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$30.00 at REI
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Overall Score
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Pros Lightweight, breathableAffordable, breathable, nice waistbandSilky fabric, stays in place, cute design, breathability, bonded seams prevent chafing and panty lines, quick dryingLightweight, quick-drying, merino woolSuper comfortable, quick to dry, lightweight, breathable
Cons Runs large, poor fit, stretches out, uncomfortable lace pattern, expensiveNot very durable, flatlock seams unraveling with minimal wearExpensive, runs largeLess practical fit, expensiveTight waistband, more expensive
Bottom Line Our testers found it difficult to recommend this pair because of its ill-fitting and uncomfortable designThe affordable price tag is alluring, though our testers were disappointed by the fit, durability, and longer drying timeSuper comfortable, breathable, and a flattering fit that allows you to forget about your undies and focus on your adventureThis is a high quality, flattering, and super comfortable bikini-cut model made out of quick drying and soft merino woolComfortable, light, and breathable, making it a good partner on lightweight adventures
Rating Categories Smartwool Merino 15... REI Co-op Active Thong ExOfficio Modern Bi... Icebreaker Siren Bi... Smartwool Merino 15...
Comfort (35%)
5.0
7.0
9.0
9.0
7.0
Fit (30%)
5.0
8.0
9.0
8.0
7.0
Drying Time (25%)
9.0
5.0
9.0
8.0
9.0
Packability (10%) Sort Icon
9.0
9.0
8.0
8.0
8.0
Specs Smartwool Merino 15... REI Co-op Active Thong ExOfficio Modern Bi... Icebreaker Siren Bi... Smartwool Merino 15...
Material 87% Merino Wool, 13% Nylon 86% Polyester, 14% Spandex Mesh, 100% Cotton Liner 82% Nylon, 18% Spandex 83% Merino Wool, 12% Nylon, 5% Lycra 87% Merino Wool, 13% Nylon Core
Measured Weight (oz) .4 oz (M) 0.4 oz (M) .8 oz (S) 1.1 oz (S) 0.7 oz (S)
Flat-lock Seams Yes Yes Seamless No Yes
Cut Tested Thong Thong Bikini Bikini Bikini
Cuts Available Bikini, thong Bikini, thong Bikini Bikini, thong Bikini


Best Overall Women's Travel Underwear


ExOfficio Modern Travel Bikini


89
OVERALL
SCORE
  • Comfort 9
  • Fit 9
  • Drying Time 9
  • Packability 8
Material: 82% Nylon, 18% Spandex | Weight: 0.8 oz
Great full coverage fit that stays in place
Super breathable & quick to dry
Bonded seams prevent chafing and panty lines
Expensive
Runs large, size down

The ExOfficio Modern Travel Bikini earned high marks in each of our four scoring metrics. These undies stood out among the competition, featuring super comfortable nylon fabric, sheer side panels that increase breathability and bonded seams that reduce panty lines. The fit hugs hips perfectly, although we do recommend sizing down. At 0.8 ounces, they weigh even less than some of the thong cuts that we tested and the bonded seams lay flat in your pack, doing its part to keep your luggage slim. They also blew the competition out of the water with a 31 minute drying time, drying even faster than some of the more compact models. All around, there is a lot to love about this underwear.

This is one of the more expensive models that we tested. However, in return for your investment, you get best-in-class performance without sacrificing aesthetics and, dare we say, a little sex appeal. These undies are our first choice for travel and backcountry adventures.

Read review: ExOfficio Modern Travel Bikini

Best Bang for the Buck


Under Armour Pure Stretch Hipster


70
OVERALL
SCORE
  • Comfort 7
  • Fit 5
  • Drying Time 9
  • Packability 8
Material: 68% Nylon, 32% Elastane | Weight: 0.7 oz
Very affordable
Soft material
Lightweight
Less comfortable fit

The Under Armour Pure Stretch Hipster immediately stood out from all other products in this review. The single rear seam creates a uniform appearance (no panty lines), and the material is considerably lighter, thinner, and stretchier than just about any other product we tested. There is a slightly higher chance of the material riding up, and we do wish there was a bit more coverage, but we love the feeling of the soft material on our skin.

The Pure Stretch also excelled in two other categories. With its thin, lightweight design, these undies are one of the lightest (just 0.7 ounces) and one of the fastest drying pairs we tested. Though this wasn't always our go-to pair, what truly makes it stand out against the competition is its price. These undies are nearly half the price of most other products in this review, a factor that we just couldn't ignore when matched with the adequate performance of the Pure Stretch. This pair is often sold as a three-pack as well, stretching the value even further.

Read review: Under Armour Pure Stretch Hipster

Best for Wool


Icebreaker Siren Bikini


84
OVERALL
SCORE
  • Comfort 9
  • Fit 8
  • Drying Time 8
  • Packability 8
Material: 83% Merino Wool, 12% Nylon, 5% Lycra Spandex | Weight: 1.1 oz
Soft material
Naturally odor-free
Breathable
True to size
Price

When we first laid our hands on the Icebreaker Siren Bikini, we couldn't believe it was wool. Icebreaker has created an incredibly soft and durable bikini made out of corespun merino 150, and we couldn't be happier with these undies. The fit is great, featuring a solid waistband that never caused us to fidget, and the cut is cute without sacrificing full coverage.

There are a few reasons you may want to consider a natural wool product over a synthetic underlayer, with the most likely reason being odor control. Wool is naturally odor-resistant, and while we didn't notice significant odor buildup in any of the products we tested, if this is the main reason you're investing in some fancier, non-cotton undies, these may be the perfect pair for you. Of the four wool bikini and hipster models we tested, the Icebreaker Siren Bikini is the best. It's light, dries fast, and is super cozy against our skin.

Read review: Icebreaker Siren Bikini

Best Thong


Icebreaker Siren Thong


86
OVERALL
SCORE
  • Comfort 9
  • Fit 9
  • Drying Time 8
  • Packability 7
Material: 83% Merino Wool, 12% Nylon, 5% Lycra Spandex | Weight: 0.9 oz
Most comfortable merino fabric
Stays in place
Quick drying
Naturally odor free
Sized accurately
Heaviest thong cut tested
Price

At first we had our doubts about taking a thong into the backcountry. That was until we tested the Icebreaker Siren Thong. This pair is so comfortable and stretchy we forgot we were even wearing underwear at all. We love the true to size fit, that offers great coverage where you want it and less where you don't, helping to conceal panty lines. The solid waistband kept everything in place and soft merino corespun fabric feels great next to our skin.

It might go without saying, but we realize that this cut isn't what everyone desires to wear. Some folks may be most happy in a hipkini or bikini cut. Additionally, the Icebreaker Merino Siren Thong is one of the more expensive models that we tested; however, we are confident that you will be satisfied with your investment. Whether you are headed out for an ultralight mission or simply want to hide panty lines beneath your favorite summer dress, these undies will not disappoint.

Read review: Icebreaker Siren Thong

Compare Products

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Score Product Price Our Take
89
$28
Editors' Choice Award
Ready for any adventure, these high performing undies do not disappoint, standing out as the best chance for most women
86
$30
Top Pick Award
Get ready for your next ultralight adventure with this quick drying, breathable, and well designed product
84
$35
Top Pick Award
This little bikini has a flattering cut that moves with you and quick drying merino wool to keep you comfortable on the trails
82
$22
Breathable and soft, the Hipster finds the middle ground between a great fit and a nice price
76
$30
Ready for lightweight adventures, this merino pair is soft, lightweight, and fast-drying
73
$24
With an outstanding fit, this is an excellent product great for any adventure
71
$17
Unfortunately you get what you pay for with this affordable price tag
70
$15
You get what you pay for, noticeably lacking the quality of other comparable models
70
$18
A long standing favorite featuring a breathable and well-constructed design
70
$12
Best Buy Award
At an incredibly low cost, this model is impressively comfortable and quick to dry
64
$30
Uncomfortable and itchy, we would recommend other merino wool thongs ahead of this pair
62
$40
Expensive and uncomfortable, this pair is soft yet heavy and slower to dry
58
$34
Itchy and heavy, with a poor fit to boot

Why You Should Trust Us


For this review, we assembled a team of the most well-traveled, adventurous staffers that we have and sent them all over the globe to put these undies to the test. Our lead tester and author, Lauren DeLaunay, took these undies to the mountains of Argentina, the beaches of Cuba, and the rainforests of Chile, where she hiked, climbed, and jumped in rivers. Oh, and did we mention the four flights and overnight bus ride to get there? When not in the southern hemisphere, Lauren spends a lot of time on the road, often living out of her van. And in the summers, she is a member of the Yosemite Search and Rescue Team. Back in Oklahoma, Trish Matheny caught the attention of her co-workers when she was preparing for her first extended backpacking trip out west by researching a single pair of merino underwear that would accompany her on the entire trip. For this review, she took these undies with her on multiple trail runs throughout the Tetons and the Sierra, up vertical rock walls in Zion and Red Rock, and to various yoga studios in between.

Click to enlarge
Click to enlarge
Click to enlarge

We started this review by spending hours in stores and on the web researching the most popular, best-selling women's travel underwear models out there. We compared specs, investigated new products on the market, and eventually chose a line-up of undergarments for rigorous hands-on testing. We wore each pair nonstop for a week to see what it could handle. We ran, climbed, swam, slept, and traveled in them, getting to know their smallest details to report our four scoring metrics accurately. In doing so, we decided that comfort, fit, drying time, and packability were the most important criteria, developing specific tests for each, including weighing each product and hanging them side-by-side to dry. After months of travel, we arrived home satisfied and confident that we found the best products available, ready to report back to make your shopping experience as easy as possible.

Related: How We Tested Travel Underwear for Women

Analysis and Test Results


We determined four crucial metrics to judge each pair of travel underwear throughout our many weeks of testing. We'll describe each metric below, including what we did to measure each category to reach objective conclusions. Because undies are a personal purchase, you may find that certain metrics are more important to you personally than what we gave them credit for. As you read each description below, make a note of anything that sounds particularly important to you, as you'll be able to look for the products with the highest scores in each metric.

Related: Buying Advice for Travel Underwear for Women

Value


We found the products in this review to vary in price significantly and understand that even the most inexpensive undergarment could be considered pricey to some. We recognize "value" to be the intersection of price and performance. Sometimes, a product performs so well that we argue it's worth the money, and sometimes we find that a less expensive product does the trick just fine.


In so many outdoor categories, higher prices allow for more luxurious materials and solid construction, and this review is no different. We are confident that you will be satisfied with your investment after purchasing the ExOfficio Modern Travel Bikini, which is more expensive than some of its competitors but gave a knockout performance in all of our testing categories. For a more affordable option, the Under Armour Pure Stretch undies are well-rounded and comfortable, with decent breathability and drying time. As the most affordable product we tested, we think these are a great buy for shoppers on a tighter budget.

Comfort


If you've ever been stuck on an overnight bus or trekked through a humid island jungle, you know that comfort is the queen of underwear performance. Because underwear makes such a high level of skin contact, comfort is paramount, and we came up with a few specific traits to look for when evaluating a product's overall comfort score.


The first thing we noticed and evaluated about each pair of undies was the material's softness. This may seem like a no-brainer, but after trying multiple pairs, we realized that there's a wide range of material textures, and each product has its unique feel. In general, we prefer the silky, thinner models to the itchy, thicker ones, as the thickness of each product contributes significantly to its breathability, another significant factor of comfort.

The ExOfficio Modern Travel Bikini features bonded seams and sheer...
The ExOfficio Modern Travel Bikini features bonded seams and sheer side panels to minimize panty lines and increase comfort.
Photo: Trish Matheny

Of all the models we tested, the highest scorers for comfort are the ExOfficio Modern Travel Bikini and the Icebreaker Siren Bikini and Siren Thong models. These products have different feels but are both silky smooth with comfortable waistbands and light and airy with excellent breathability. We like the Icebreaker's waistband a bit more, but ExOfficio is right up there in performance and comfort with its bonded seams. Perhaps the greatest compliment here is that once we were dressed and headed out the door with these three pairs, we never thought about what underwear we were wearing.

Two competitors tied for second place: the ExOfficio Give-N-Go 2.0 and the Patagonia Barely Hipster. We love the soft and stretchy material of the Barely Hipster, and even though the Give-N-Go is a little bit heavier, the material is still very smooth. Because comfort is so important to the enjoyment of our undergarments, we weighted "comfort" as 30% of each product's overall score.

We preferred removing the manufacturer tags to increase next to skin...
We preferred removing the manufacturer tags to increase next to skin comfort.
Photo: Trish Matheny

Fit


At first, we were going to include "fit" into the comfort category, but after months of testing, our team agreed that there were enough traits unique to "fit" that another metric was warranted. For this product, we looked less at the materials and more at the cut. To be consistent, we generally choose either bikini, hipster, or thong models, though many of these products have sister models in other shapes and cuts.


We dealt with an unfortunately high number of wedgies on this review and learned quickly that this was an instant deal-breaker. A few factors cause wedgies, some of which remain mysteries to us. However, we did find a strong correlation between the fit of the leg openings and the likelihood of wedgies. The Barely Hipster, for example, has tight leg openings that do a great job at keeping the garment in place, while the Icebreaker Sprite features loose openings that often give a wedgie.

The fit of the Active Hipster is secure, comfy, and ready for any...
The fit of the Active Hipster is secure, comfy, and ready for any adventure.
Photo: Lauren DeLaunay

While all the models in this review have different waistbands, from the seamless one of the Under Armour Pure Stretch to the thick band of the Active Hipster, there is no single shape that's more appealing, though we prefer a stretchy waistband overall. As you may assume, stretchiness was a huge factor in a product's "fit" score, and our favorite products were those that let us move freely while they stayed in place. The Barely Hipster and Icebreaker Siren Bikini achieve this well with ultra-stretchy fits and leg openings that are snug yet comfortable. The ExOfficio Modern Travel Bikini also excels in this metric. This pair hugs our waist, staring in place, and they stay in place through active use all day long.

The Patagonia Barely Hipster fits great and is made out of comfy...
The Patagonia Barely Hipster fits great and is made out of comfy materials with enough stretch to move with you.
Photo: Trish Matheny

Drying Time


The time needed to air dry is an important factor in the overall score of a pair of travel underwear for two big reasons: sweat and washing. The ability of our base layers to dry quickly on the go is crucial to keeping us comfortable. Similarly, when we're on the run from city to city and have a plane to catch, a quick wash in the sink is the perfect remedy. But if our undies take too long to dry, valuable time could be wasted.


To test for this metric, we soaked each product in water and hung them to dry. We tried various methods, including wringing out the garments by hand and with a towel and found consistent results across the board. In general, the thinner the material, the quicker the drying time. It's no surprise, then, that the ExOfficio Modern Travel Bikini and Pure Stretch are such high scorers in this category.

What's the Deal with Washing?

We've mentioned washing on the go as an integral part of long-term travel, so we thought we'd pause here to add a few tips. Washing your undies in the sink is a great travel option. Usually, we run out of underwear before we need to wash the rest of our clothes. So while the sink may not work for your jeans and jackets, it will extend the time before you have to make a trip to the laundromat. First, find something to plug the drain. Fill the sink with hot water and let the garments soak until fully saturated. Pour in some detergent and scrub each garment, using its own material to scrub dirtier sections. While there are some convenient single-use laundry detergents out there, we prefer a more versatile product such as Dr. Bronner's that can be used to wash our clothes or our hair. When space is limited, finding products that have multiple purposes helps save space.

Wringing out the water in the ExOfficio Give-N-Go 2.0 before...
Wringing out the water in the ExOfficio Give-N-Go 2.0 before starting our timer.
Photo: Trish Matheny

One of our favorite drying methods is the towel-roll method. We used this consistently during our testing, and we'll never forget it. Lay your undies on a towel and roll it up. Then you can wring out the towel, forcing water from the undies into the towel. The products will be considerably drier than if you just wring them out by hand, cutting down on your drying time so you can get back to your adventures as soon as possible. We're also a fan of strapping our socks and undies to the outside of our packs while backpacking to get them to dry while not taking up too much of our time.

If you're going to wash your clothes in a stream or river, we recommend doing your research and using eco-friendly soaps. Ideally, you can use the water from a river to wash your clothes in a bag or bucket away from the water source itself. A dry bag works great for this purpose, and there are even some new "washing bags" on the market. These are basically dry bags with scrubby internal nodules. While we haven't tested them out ourselves, these could make for a great option if you're hitting the road for an extended period without weight as a concern. We probably wouldn't carry this into the backcountry with us. Additionally, we're often surprised by how well a quick rinse and scrub without detergent does at getting the sweat out of our garments, keeping us fresher longer before we have to return home. No matter what method you choose, a quick drying time keeps you out there having fun longer, which is precisely why this metric was such an essential part of our testing process.

Undies drying on the line outside the cabin in Victor, Idaho during...
Undies drying on the line outside the cabin in Victor, Idaho during one of our drying tests. The ExOfficio Modern Travel Bikini dried in just 31 minutes.
Photo: Trish Matheny

Packability


Because one of our primary goals with the products in this review was to be able to pack them up and go into the backcountry for extended periods, weight and compactness are of the utmost importance. That being said, the weight of each pair varies by fractions of an ounce, and differences in packed size are small when compressed in a travel bag or suitcase. We wouldn't use this metric as your sole or top deciding measure, but it's worthy of a tie-breaker status. For this reason, "packability" was only 10% of each product's overall score.


For weight, we put each product on our scale to see how they stacked up. The weights ranged from 0.35 to 1.4 ounces with the top scorers, the Smartwool Merino 150 Lace Thong, the REI Co-op Active Thong, and the REI Co-op Active Bikini coming in at 0.35, 0.42 oz or 0.6 ounces, respectively.

The Merino Siren Thong packs down smaller than a bandana.
The Merino Siren Thong packs down smaller than a bandana.
Photo: Trish Matheny

In addition to weight, our testing team looks at the compactness of each product. The thinner, stretchier materials tend to fold down to a flatter, smaller package, and some take up more room in our packs or suitcases than others. Again, these measurements are within fractions of an inch. While packability is undoubtedly important, we suggest evaluating potential purchases by their scores in other categories first and then use this metric to make a final call.

Comparing packed size of the travel underwear we tested, with the...
Comparing packed size of the travel underwear we tested, with the Icebreaker Siren and REI Active Pursuits models (right side) packing up smallest.
Photo: Trish Matheny

Conclusion


Fussing over your underwear might seem a little unnecessary, but after weeks on the road, we can tell you that comfortable travel undeniably starts with undies. From comfortable material to enough stretch to move, the construction of each pair of undies is critical to its performance. Keeping dry in a wide variety of climates is just as important as drying quickly after a hand-wash. During weeks of testing throughout multiple seasons, we found a few stand-out performers in performance, price, and material. We hope our suggestions help you along for journeys to come.

Lauren Delaunay & Trish Matheny