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When you’re hiking hard, your apparel needs to be just as durable and comfortable as any other piece of gear. The best underwear for hiking should wick moisture, stay in place, and resist odor. Men and women hikers took these pairs into the field to determine the best pairs to keep you dry and comfortable on trail.
Men’s
- Best for Men: Icebreaker Cool-Lite Merino Anatomica Boxers
- Best Thermal Underwear: Smartwool Merino 150
- Best Synthetic: Royal Robbins Readydry Boxer Brief
- Patagonia Sender Boxer Briefs
- Smartwool Merino Boxer Brief
- Minus33 Woolverino Micro Weight Wool Boxer Shorts
Women’s
- Best for Women: Ibex Women’s Natural Brief
- Best Thermal Underwear: Montbell Super Merino Wool Lightweight
- Best Full-Coverage: Icebreaker Merino Siren Bikini Briefs
- Best Synthetic: Patagonia Women’s Active Hipster
- Best Wool Alternative: Paka Alpaca Underwear
- Best Medium-Coverage: Smartwool Merino Brief
- Paradis Sport Seamless Thong
How We Tested the Best Underwear for Hiking
Outdoor Life testers wore the best underwear for hiking on 20 mile walks around town, on trails, and while backpacking. We wore them for multiple days to test odor control and noted each’s ability to retain its shape and stay in place even during vigorous exercise.
Best Men’s Underwear for Hiking: Reviews & Recommendations
Best for Men: Icebreaker Cool-Lite Merino Anatomica Boxers
Key Features
- Sizes: S-XXL
- Fabric Content: 50 percent merino wool, 33 percent lyocell, 12 percent nylon, 5 percent elastane
- Available Styles: Trunks, boxers
Pros
- Comfortable
- Secure
- Odor resistant
Cons
- Line dry
Icebreaker’s Cool-Lite Merino Anatomica boxers were our tester’s overall favorite. The high merino content and flat-lock seams provide a comfortable and secure fit without chafing. These boxers are breathable and moisture wicking with a snug fit without compression. Of the merino wool picks, Icebreaker was the only one that was odor resistant and kept its comfort and shape over several days and miles. That makes these the best men’s underwear for hiking.
Best Thermal Underwear: Smartwool Merino 150
Key Features
- Slim fit
- Flatlock seam construction
- 87 percent merino wool, 13 percent nylon core
- Weight: 6 ounces
Pros
- Slim, lightweight
- Durable
- Super warm
- Not restricting
- Multiple colors and patterns
Cons
- Too warm for some activities
I have been a fan of Smartwool for years. Their products are durable and downright comfortable, and the 150 line is no exception. Once I slipped the tops and bottoms on, I almost forgot I was wearing them. And I don’t mind wearing these all day. These Merino layers do a fantastic job of regulating your body temperature and wicking moisture. I’ve used them skiing, camping, and hiking in cold temps, and I’m always impressed by how well their profile contours your body and keeps you warm. Pair these with some of the best hiking pants, and you’ll be prepared to face even the most frigid temps outdoors.
Read Next: Best Thermal Underwear for Men
Best Synthetic: Royal Robbins Readydry Boxer Brief
Key Features
- Sizes: S-XXL
- Fabric Content: 94 percent polyester, 6 percent elastane
- Available Styles: Boxers, 4-inch boxer briefs, 7-inch boxer briefs, briefs
Pros
- Comfortable
- Secure
- Made with recycled polyester
Cons
- Not very odor resistant
Royal Robbins was our tester’s favorite synthetic hiking underwear for men. While the Readydry boxer brief was less comfortable than Icebreaker, they were far more comfortable than the other synthetics. The breathable mesh fabric and flat locked seams retained their fit and flexibility without chafing. However, like other synthetics, it started to smell after the second day. If your skin is too sensitive for wool or prefer synthetic materials, these are a great pick for all-day comfort.
Patagonia Sender Boxer Briefs
Key Features
- Sizes: S-XXL
- Fabric Content: 89 percent recycled nylon, 11 percent spandex mesh
- Available Styles: Boxer briefs
Pros
- Comfortable waistband
- Recycled nylon
Cons
- Not very odor resistant
The Sender boxer briefs from Patagonia are another good synthetic option. However, synthetics won’t provide the same odor resistance as wool options. The Sender’s waistband design is secure with no rolling, and a comfortable fit. And the recycled material is low maintenance: machine washable and tumble dry.
Smartwool Merino Boxer Brief
Key Features
- Sizes: S-XXL
- Fabric Content: 88 percent merino wool, 12 percent nylon
- Available Styles: Boxers, boxer briefs
Pros
- Odor resistant
- Temperature regulating
Cons
- Fit issues
While Smartwool’s merino boxer briefs are temperature regulating and odor resistant, our tester experienced some fit issues that held this pair back. The thick band and loose leg fit resulted in many wedgies. Depending on your body type, this pair could still perform for you, just be wary if riding up is a typical issue you experience with adventure underwear.
Minus33 Woolverino Micro Weight Wool Boxer Shorts
Key Features
- Sizes: S-XXL
- Fabric Content: 84 percent merino wool, 12 percent nylon, 4 percent spandex
- Available Styles: Boxers, boxer briefs, briefs
Pros
- Odor resistant
- Temperature regulating
Cons
- Fit issues
Similarly to the Smartwool, Minus 33 was noticeably less comfortable for our tester owing to the thin band and loose leg fit. In the case of Minus 33, this could be because it’s a boxer short, but overall, the tester felt as though he was wearing a merino wool diaper in both pairs. I also tested the Minus 33 women’s boyshorts and found that the legs do curl up at any opportunity. The soft merino wool and loose fit makes these better for lounging at camp than hiking there.
Best Women’s Underwear for Hiking: Reviews & Recommendations
Best Overall: Ibex Women’s Natural Brief
Key Features
- Sizes: XS-XL
- Fabric Content: 83 percent merino wool, 12 percent nylon, 5 percent elastane
- Available Styles: Brief, thong
Pros
- Odor resistant
- Comfortable
- Good coverage
Cons
- Thinner waistband
You might think of wool as a winter-exclusive material and not at all what you want rubbing on your bum all day. But wool has a ton of great features that make the best hiking socks and this merino underwear ideal for year-round adventures. While wool has a reputation for being scratchy, ultra-fine merino wool is very soft. It also has a number of qualities that traditional cotton underwear does not, helping to regulate your body temperature, drying out quickly, and breathing surprisingly well. The high merino wool content in Ibex’s natural hiking underwear gives them excellent odor control and a comfortable feel.
During testing, they provided good coverage, with no slipping. They stayed comfortable when they were wet, as well as for multiple days in a row on longer backpacking trips. This is because the merino wicks away moisture while the naturally antimicrobial fabric lets go of smells. But they’re also soft and comfortable enough for everyday wear. The elastic is thinner, but it is soft and recovers well so it doesn’t dig in or stretch out.
Best Thermal Underwear: Montbell Super Merino Wool Lightweight Tights
Key Features
- Fabric Content: 85 percent merino wool, 15 percent polyester
- Weight: 4 ounces
- Available Sizes: S through L
- Pair with Montbell Super Merino Wool Lightweight Shirt
Pros
- Soft and comfortable
- Lightweight and thin material will layer under almost anything
- Affordably priced
Cons
- Fabric is thin to the point of being sheer
The Montbell Super Merino Wool Lightweight Shirt and Tights had everything we wanted: a soft, comfortable skin feel, great thermoregulation, good fit, and affordable price. Testers noted that it was surprisingly soft given the high percentage of merino wool and that it hugged their body more than other layers we tried. That’s helpful for both quickly wicking sweat away from your skin and reducing bulk when you layer other clothing on top of it.
The high merino wool content meant we could go longer between washes with this layer than with the synthetic thermal underwear we tested; but even so, we ended up washing our favorite top frequently over the spring and summer. We’re happy to report that it still looks the same as when we first received it in the mail: no pilling, no stray strings, no holes. This is doubly impressive given that this layer is so thin it’s practically sheer.
Read Next: Best Thermal Underwear for Women
Best Full-Coverage: Icebreaker Merino Siren Bikini Briefs
Key Features
- Sizes: XS to XL
- Weight: 1.12 ounces (small)
- Fabric Content: 83 percent merino wool, 12 percent nylon, 5 percent lycra
- Available Styles: Bikini brief, hipkini brief, thong
Pros
- Soft
- Dries quickly
- Multiple styles available
Cons
- Stretches out more quickly in between washes
The Icebreaker has a very similar fabric composition to the Ibex hiking underwear. They even have a similar cut. Icebreaker uses merino corespun, a durable merino blend where finer merino strands, with all of their performance benefits, are wrapped around a stronger nylon core. This allows your hiking underwear to regulate your body temperature in all weather conditions, wick moisture, and prevent smells while lasting longer.
The icebreaker is available in the hipkini brief for even more coverage than the bikini brief, or a thong. During testing, the fabric did tend to give more and stretch out a bit quicker than the Ibex natural brief in between washes.
Best Synthetic: Patagonia Women’s Active Hipster
Key Features
- Sizes: XS to XL
- Weight: 1.1 ounces
- Fabric Content: 88 percent nylon (40 percent recycled),12 percent spandex
- Available Styles: Bikini, hipkini, barely hipkini
Pros
- miDori bioSoft for added wicking and softness
- HeiQ Pure provides odor control
Cons
- Not wool
- No thong option
If you have a wool sensitivity, or just a wool addiction, this synthetic option from Patagonia is a nice change of pace. OL’s resident wool-head Laura Lancaster says she wouldn’t normally pick a synthetic pair of underwear for hiking, but she found them comfortable and surprisingly capable.
The miDori bioSoft is a softening treatment that aids in moisture wicking by helping the fabric absorb more moisture and expediting evaporation. HeiQ Pure is a 90 percent bio-based treatment that prevents odor from clinging to your clothes with a small amount of recycled silver and salt. These are slightly cheaper than our wool picks and have a couple style choices. The barely hipkini features a smaller waistband than the active models.
Best Wool Alternative: Paka Alpaca Underwear
Key Features
- Sizes: XS-XXL
- Fabric Content: 48 percent tencel, 33 percent organic cotton, 14 percent royal alpaca, 5 percent spandex (in waistband)
- Available Styles: Brief
Pros
- Breathable
- Soft
- Odor resistant
Cons
- Only one style
Paka’s soft and lightweight briefs stay in place and resist odor. They’re breathable and stretchy for unrestricted motion and comfort. The alpaca fibers provide moisture wicking, anti-microbial properties, and odor resistance. If you’ve struggled with sheep’s wool in the past, alpaca wool is worth a try.
Best Medium-Coverage: Smartwool Merino Brief
Key Features
- Sizes: XS to XL
- Fabric Content: 88 percent merino wool, 12 percent nylon
Pros
- Stretchy
- Soft elastic
Cons
- Wedgie-prone
Smartwool uses a similar spinning technique to Icebreaker where the durable nylon is encased in soft merino fibers. The fabric feels soft, stretchy, and breathable. The slim cut is designed to hug your curves. However for those with hiker glutes, this underwear tends to stretch and slide into an uncomfortable position.
The wool is quality with nice odor control and moisture wicking. But the medium-coverage cut and stretchability means for some, it won’t stay in place while hiking. If you tend to prefer a slim cut or want extra stretch in the fabric, these could prove to be very comfortable.
Paradis Sport Seamless Thong
Key Features
- Sizes: S to L
- Fabric Content: 94 percent nylon and 6 percent spandex
- Available Styles: Bikini, thong
Pros
- Made in the USA
- Stays in place
- Breathable
Cons
- Thin
- No odor control
- Tight
Paradis Sport is creating soft, athletic underwear that stays in place while exercising. The brief and thong have stretch, moisture-wicking, and quick-drying qualities for hiking. The fabric is thinner allowing for the right amount of support and breathability. However, the thinness might have contributed to some pilling on the rear of the bikini.
The thong’s thick waistband never rolls and the material feels fresh on my skin. Best for day hikes or short backpacking trips, these don’t offer much odor control. Now a natural fiber version is available using micro-modal which is sustainably harvested from beech tree pulp. However, I no longer reach for the Paradis sport underwear because while they never budge on long hikes, they are tight and irritating on the groin area. If this fit issue sounds bothersome to you, opt for something more loose fitting.
How to Choose the Best Underwear for Hiking
The best hiking underwear should stay in place, feel comfortable, dry quickly, and reduce odor. Your body type will likely have a lot to do with the staying power and comfort of your underwear so check sizes, styles, and measurements like you would other performance apparel. Sweat, rain, and river crossings can dampen your drawers so a fast dry-time will keep you more comfortable. If you’re traveling, you might also need to wash clothes on the go and the faster your first layer dries, the better. Odor control is great on trail to town days and when you’re hiking for days or weeks at a time.
FAQs
Wool underwear wicks moisture, breaths, and resists odor better than synthetic materials. If you’re sweating a lot while hiking, turn to the thermoregulating and odor control powers of merino wool.
If it’s very cold outside, you might opt for long underwear while hiking. But when you’re on the move, your body will start to heat up. Typically pants or shorts with a pair of performance underwear is sufficient.
Yes, if you choose to wear thermal underwear for hiking, I would recommend wearing underwear underneath. This will keep your thermals cleaner for multiple wears.
Final Thoughts on the Best Underwear for Hiking
The best underwear for hiking is dependent on your personal comfort. To help you find pairs that perform on trail and fit comfortably, we took some of the top brands hiking and backpacking. While fit is subjective, the design and materials of every pair on this list is up to the hard hiking.
Men’s
- Best for Men: Icebreaker Cool-Lite Merino Anatomica Boxers
- Best Thermal Underwear: Smartwool Merino 150
- Best Synthetic: Royal Robbins Readydry Boxer Brief
- Patagonia Sender Boxer Briefs
- Smartwool Merino Boxer Brief
- Minus33 Woolverino Micro Weight Wool Boxer Shorts
Women’s
- Best for Women: Ibex Women’s Natural Brief
- Best Thermal Underwear: Montbell Super Merino Wool Lightweight
- Best Full-Coverage: Icebreaker Merino Siren Bikini Briefs
- Best Synthetic: Patagonia Women’s Active Hipster
- Best Wool Alternative: Paka Alpaca Underwear
- Best Medium-Coverage: Smartwool Merino Brief
- Paradis Sport Seamless Thong