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Icebreaker Siren Thong Review

This exceptional thong-cut garment is a super comfortable, well-designed product that excels in urban and backcountry travel
Icebreaker Siren Thong
Photo: Icebreaker
Top Pick Award
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Price:  $30 List | $30.00 at REI
Compare prices at 3 resellers
Pros:  Most comfortable fabric, well-constructed design, quick drying, true to size
Cons:  Expensive, heaviest thong tested
Manufacturer:   Icebreaker
By Trish Matheny ⋅ Review Editor  ⋅  Jul 13, 2021
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86
OVERALL
SCORE


RANKED
#2 of 13
  • Comfort - 35% 9
  • Fit - 30% 9
  • Drying Time - 25% 8
  • Packability - 10% 7

Our Verdict

We are impressed by the Icebreaker Merino Siren Thong because of its double merino wool corespun fabric that affords comfort and moisture-wicking capabilities, as well as the overall fit that allows us to move our bodies and forget we are even wearing underwear, let alone a thong. This garment is for the person who appreciates a little luxury when on the go, away from the comforts of home. In return for your investment, you will receive a super comfortable, quick-drying, breathable product that performs flawlessly during active or casual use.

Compare to Similar Products

 
Awards Top Pick Award Editors' Choice Award Top Pick Award  Best Buy Award 
Price $30.00 at REI
Compare at 3 sellers
$28 List
Check Price at REI
$22.75 at Backcountry
Compare at 3 sellers
$22.00 at REI
Compare at 2 sellers
$12 List
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Pros Most comfortable fabric, well-constructed design, quick drying, true to sizeSilky fabric, stays in place, cute design, breathability, bonded seams prevent chafing and panty lines, quick dryingLightweight, quick-drying, merino woolBreathable, comfortable, inexpensiveInexpensive, soft, quick-drying, no bulky seams
Cons Expensive, heaviest thong testedExpensive, runs largeLess practical fit, expensiveTight fitImperfect fit for some
Bottom Line This exceptional thong-cut garment is a super comfortable, well-designed product that excels in urban and backcountry travelSuper 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 woolThe Barely Hipster is a super comfortable and affordable product made to stand the heatSoft, stretchy, and quick to dry, this value-forward garment won us over without making us pay a high price
Rating Categories Icebreaker Siren Thong Modern Travel Bikini Icebreaker Siren Bi... Patagonia Barely Hi... Pure Stretch Hipster
Comfort (35%)
9.0
9.0
9.0
8.0
7.0
Fit (30%)
9.0
9.0
8.0
9.0
5.0
Drying Time (25%)
8.0
9.0
8.0
8.0
9.0
Packability (10%)
7.0
8.0
8.0
7.0
8.0
Specs Icebreaker Siren Thong Modern Travel Bikini Icebreaker Siren Bi... Patagonia Barely Hi... Pure Stretch Hipster
Material 83% Merino Wool, 12% Nylon, 5% Lycra Spandex 82% Nylon, 18% Spandex 83% Merino Wool, 12% Nylon, 5% Lycra 89% Nylon, 11% Spandex 68% Nylon, 32% Elastane
Measured Weight (oz) .9 oz (M) .8 oz (S) 1.1 oz (S) 0.8 oz (S) 0.7 oz (S)
Flat-lock Seams Yes Seamless No Seamless Seamless
Cut Tested Thong Bikini Bikini Hipster Hipster
Cuts Available Thong, bikini, hipster Bikini Bikini, thong Hipster, bikini, thong Hipster, cheeky, thong

Our Analysis and Test Results

The Icebreaker Merino Siren Thong stands out from the competition. The soft and comfortable merino corespun fabric feels great on the body with enough stretch to allow for freedom of movement, along with a great waistband to hold things in place. This thong received high scores in almost every testing category and became one of our go-to's as an ultralight thong for extended travel.

Performance Comparison


We loved the stretchy waistband of the Merino Siren Thong for...
We loved the stretchy waistband of the Merino Siren Thong for overall comfort and performance.
Photo: Trish Matheny

Comfort


We believe comfort is key to any garment that you'll be traveling with for an extended period, so we began by testing each pair of underwear side by side to evaluate the level of comfort next to skin, whether or not the fabric was breathable during activity, how thick the material was when compared to other garments, and finally, the type of material the garment is constructed from.


The Merino Siren Thong earns high marks in this category because of the incredibly soft next-to-skin feel and breathability of the corespun, mostly merino fabric. The unique fabric, made out of 83% merino, 12% nylon, and 5% elastane, helps to regulate your body temperature during high activity and wick away moisture. The Siren Thong quickly became our go-to thong, even while recreating and being active. It is so comfortable that it remains unnoticeable throughout the day, which is what we want in underwear.

We maximized the overall comfort of the underwear that we tested by...
We maximized the overall comfort of the underwear that we tested by removing the tags for a smooth next to skin surface.
Photo: Trish Matheny

Fit


To score the fit for each pair of underwear, we considered the details of the cut, how well it covered our body, whether or not the material was stretchy enough to move with us, and if the waistband did its job of holding the garment in place.


The cut is true to size, offering great coverage where you want it and less where you don't, making it a great option to hide those distracting panty lines or appreciate during your next adventure. We love the waistband on this thong over the flatlock seams of other merino wool options. The stretch allows for freedom but is also tight enough to provide control so we never need to adjust. When considering overall fit, including just the right amount of stretch, the Merino Siren Thong is our favorite out of the thong cuts we put to the test.

We are super impressed by the Merino Siren Thong fabric; enough...
We are super impressed by the Merino Siren Thong fabric; enough stretch to offer freedom of movement with a great waistband to hold things in place.
Photo: Trish Matheny

Drying Time


We tested the drying time of each pair of underwear on a spring day in Victor, Idaho in between travels by soaking each pair in water, wringing them out by hand, and then hanging each pair on a line to dry in partial sun with a light breeze.


The Icebreaker Merino Siren Thong gives a top-notch performance in this category, completely dry in a time of 44 minutes. The super-soft merino fabric also dried quickly from sweat during high-performance activity, again allowing us to move freely and not become distracted by the discomfort of our underwear. We even took a dip in an alpine lake with these undies and after wringing them out, they dried on the body during movement before we even finished the descent.

The Merino Siren Thong dries in well under an hour.
The Merino Siren Thong dries in well under an hour.
Photo: Trish Matheny

Packability


We understand that every ounce counts when it comes to extended travel and carrying all your essentials on your back. To test for the overall packability, we decided to weigh each garment on our scale and then we performed a side-by-side comparison between each garment to assess which model required the least amount of space within luggage or a backpack.


Weighing in at .88 ounces, the Merino Siren Thong is heavy compared to the thong cuts we tested. We attribute this extra weight to the double merino corespun fabric which not only increases comfort, but also helps to wick moisture away from the body. We understand that selecting a thong cut over a hipkini can help to shave ounces off the weight of your pack, however, when we compared each pair for their compact size and minimal space requirements, we noticed little difference in terms of bulk. While the Siren Thong is not the lightest in the bunch, we are pleased to sacrifice a small amount of weight for luxurious comfort, fit, and breathability.

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

Value


The Merino Siren Thong is one of the more expensive garments that we tested from minimal thongs to full coverage hipkinis. However, who doesn't want a little luxury when traveling away from the comfort of home? In return for your investment, you receive a high-quality, well-designed product that will make you forget you are even wearing underwear, making the Icebreaker Merino Siren Thong not only worth its weight but also worth the price.

Conclusion


If thongs are your preference, we strongly recommend the Icebreaker Merino Siren Thong for travel. Featuring a double merino corespun fabric that is not only quick-drying and breathable but will also keep you comfortable during your next adventure. Hands down, it's our favorite of all thong cuts we tested.

Our favorite travel thong, the Merino Siren Thong features a great...
Our favorite travel thong, the Merino Siren Thong features a great fit with optimal breathability.
Photo: Trish Matheny

Trish Matheny