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The soft, lightweight knit and smooth, flat seams on the SmartWool Women's Microweight Hiphugger Undewear can be confusing, because these features don't line up at all with what most people think of when they hear the term 'wool underwear.' But this performance brief isn't the slightest bit itchy, bulky, or saggy; rather, the soft merino wool-elastane blend hugs your curves, regulates moisture against your skin, and fights odors. So check your preconceptions at the door.

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Size down, stretches A LOT

  • Familiarity: I've put it through the wringer
  • Fit: Runs large
  • Size Bought: medium

I ordered this in medium and small originally, but returned the small because the small felt slightly tight and the mediums fit perfectly when I initially tried them on. After wearing for a little bit, the material stretches a lot and can bunch up. The material feels good and wicks well. I currently save this underwear for under thicker material pants (like jeans) or laundry days. If I order again I would size down.

Is this love at first sight?

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: True to size

I ordered one pair of these to see if they are really as awesome as I hope, and so far it's promising. When they arrived, I tried them on about six different times because I just couldn't make up my mind about whether to keep them or return them because of the cut.

Smartwool calls these 'mid rise' underwear, but I find them to be super-ultra-absolutely low rise on me. They are low on my hips (aghhh....buttcrack!) and even lower at the leg. It feels like they cover more of my leg than my behind, like 'boy shorts' without the inseam and shorts part. I kinda wish that just one inch of fabric was redistributed to be higher cut on the leg and higher in the back.

I agree with other reviewers that the fabric is generally fantastic (same pointelle fabric as my Smartwool micro weight base layers), and the seams are nice. I'm not worried about longevity because I mend things and Smartwool has a lovely lifetime warranty (stick to your wool wash!). I generally wear XL in my Smartwool items and these fit as expected.

I thought about trying the bikini version instead, but it looks to be of the same "mid rise is actually low rise' design, and I usually prefer a bit more coverage anyway. Smartwool has a PhD bikini that looks to be more high cut in the back, but it's 15% nylon and I am committed to full merino on a long, sweaty trip, so these hiphuggers are the undies of choice.

Final decision: After a day of running around, these have turned out to be low, but comfy and not shifting/sliding down when I'm moving. They might be THE ONES despite my initial concerns. They pretty much look and feel invisible. I was worried that they would be uncomfortable or at least irritating because I'm a sensitive texture/tag/seam person, and these are such a different design than my typical undergarments, but they are like a dreamy cloud. Definitely worth getting a few pair on sale.

disappointing cut

  • Familiarity: I've put it through the wringer
  • Fit: True to size

I have half a dozen pair of the Smartwool microweight bikinis. Love them! But the hip hugger cut actually makes it look like I have a muffin top of sorts at the hip. They also cut across the rear at an odd spot. Not at all flattering. Is it weird to return underwear? My waist is 28, hips are 38, and a medium fit nicely.

Great undies

  • Familiarity: I've used it several times
  • Fit: True to size

These are extremely comfortable and the thin band leaves almost an unnoticeable panty line. These are great for trips where you might have to wear them multiple days. The colors are cute and i love the cut.

The BEST :)

  • Familiarity: I've used it several times
  • Fit: True to size

These are the most comfortable underwear I've ever had. After getting the initial couple of pairs, I got several more pairs, and then some, while they were on sale and couldn't be happier.


  • Familiarity: I've put it through the wringer
  • Fit: True to size

These undies are well worth the money! They hold up well and I've worn them for up to eight days before they're washed (and could have gone longer). Great investment!!!!!! The fit is great and they're comfy (not itchy) and incredibly soft! No wedgies, unlike other "technical" undies. I'm 5'3, about 115 pounds, and I wear an XS. I wash them and line dry :)

cute and functional

  • Familiarity: I've used it several times
  • Fit: True to size

I have the heather gray ones with the blue elastic. The blue actually has shades and hits of other colors in the band adding some fun detail. These undies are quite comfortable. I was expecting the fabric itself to be more stretchy but I should have payed closer attention to the 95% merino wool label. These are not itchy or scratchy at all, so if you are looking for undies with the cotton like feel and look but more wicking ability you have found them.


    Bought a few pairs for skiing and hiking this winter. I have tried Ibex and Icebreaker and these have the best fit and fabric by far. They also held up great for two weeks of touring, skiing, and hut living above the arctic circle in Norway. I am slowly stocking up on more and more for every day use. I also avoid the dryer and hang mine to dry. Something I do for all the merino I own, just to be on the safe side.

    Bad quality

      These are great fabric, great fit, soft, sadly though, they have poor quality. Mine started unraveling at the top after about 3 washes (no dryer). I expect better from $30 underwear.

      Great as always

      • Familiarity: I've put it through the wringer

      Got another pair...grey this time. And great as always. Running, skiing, long days in the OR. Expect nothing less from smartwool and backcountry. I'd advise against drying. No major skrinkage but changes the wool a bit. TTS. L and I'm 5'8 size 10/12.

      Mostly great

      • Familiarity: I've used it several times

      I bought 6 pairs for a trip. 5 have held up great, 1 fell apart after about 3 washes. While this is clearly an anomaly it prevents the 5 stars.

      That said, they don't ride up. They fit really well, feel weightless on, clean easily and dry quickly.

      Best Underwear Ever!!!

        Simply put wish I could replace every pair of underwear I own with these. And the sale price didn't hurt other. Seriously so comfy even while working out. They never move and no awful lines. Washed well- I hung dry so they didn't shrink or fray. My only wish is they hadn't sold out in the grey in my size.

        Best Underwear I've Ever Owned

          I'm not surprised to see that my size is sold out in every color now - you need to grab a pair of these before they sell out! The fit/coverage in the back is great - these will never ride and fit perfectly. I can rinse these out at night after a hike and they're dry and like-new in the morning. These are my go to for all sports and they're even a perfect fit under jeans because they're so sleek. I hope more of these come into stock, I would buy the whole inventory.

          Poor quality

            I wore these once and somehow, they got a whole in the material, i.e. not along the seams. I'd like to send them back, but feel weird about doing this. On the other hand, they were close to $30 and I expected the workmanship/material to be of better quality.


              Wore this for an undisclosed amount of time climbing up Kilimanjaro and they never bunched, stunk, caused any itching or hot spots. A little pricey, but worth it. I bought a medium (my usual size) and it fit perfectly. I'm a little curvy back there so I was surprised when they fit me so well.