Branwyn Essential Thong Review

Finding the right underwear for backpacking is quite the challenge. It has to hold up to multiple days of wear and lots of sweat.

The Branwyn Essential Thong is made from ethically acquired merino and is built for comfort, a low profile, and to keep you feeling fresh all day long. Let’s be clear though, it is a thong — you should know if that’s what right for you before you try it out.

Photo: Branwyn

Branwyn Essential Thong at a Glance

MSRP: $30
Material: 81% extra fine merino wool, 12% nylon, and 7% Spandex
Fit: Seamless and low rise

Circumstances of Review & Intended Use

 I’ve worn the essential hike out on multiple day hikes, days skiing, and a backpacking trip this fall. These are designed to be “barely there” for all day comfort, while also keeping you dry and funk free. I’ve worn these plenty of times while active to truly put them to the test.


Merino: Branwyn uses merino wool for it’s ability to be quick drying and to keep things fresh down there. Their wool is also ZQ, OEKO-TEX, and Responsible Wool Standard certified merino is also regenerative and sustainable. (Which also means it is free of BPA, BHP, and toxic forever chemicals.)

Seamless: The thong is designed to be low-profile and seamless. This keeps seams from rubbing, but also keep them invisible, aka no panty lines — even through leggings.

Comfort Waistband: The comfort waist band keeps the underwear from digging in or rolling out of place no matter what activity you’re doing and which way you’re bending. 

Comfort and Fit

The Essential Thong fits as expected for me, so check the size chart and order your usual size. They’re comfortable, and they definitely hug tight to your body. I found this fit great for staying in place all day, but it’s not the most flattering if that’s something you care about. It’s worth saying this too: it’s a thong, and that’s not for everyone. They do a great job at covering only what you want, and not leaving any panty lines. 

Odor Prevention

This was the first pair of merino underwear I’ve personally tried, but I’ve been wanting to for a while. The change in keeping funk-free after a long day of hiking or a tough workout was instantly noticeable. The odor-neutralizing and naturally breathable properties of the merino work exceptionally well when compared to synthetics I’ve mostly used before. 

Wicking Capabilities

I was also impressed by how dry this underwear stays, even after a full day of sweating. That’s another great property of the merino blend. It was again a noticeable difference from synthetic underwear I’ve previously used. This also helps to keep you warmer, another great quality of merino, but the warmth isn’t the most noticeable as a standalone feature since the thong doesn’t cover much.


These have held up great, showing no signs of wear through many washes. The material feels strong and like it will last; no pulls or other signs of damage have shown whatsoever. It is important not to put them through the dryer so as to not shrink or damage the fabric. There are easy-to-follow care instruction on Branwyn’s site.


Branwyn takes every step possible to make their products more sustainable. From using ethically sourced merino and waste-reducing knitting technology to the brand’s recyclable and compostable packaging, they truly make an effort. This is something I always care about in an outdoor company. 

Photo: Branwyn


Comfortable: The Essential Thong was comfortable to wear all day long and never bunched up or moved no matter how much I moved.

Moisture Wicking: These stayed dry and kept me warm even after all day hiking and sweating.

Odor Control: The merino kept everything fresh with it’s odor prevention properties, unlike many synthetic pairs of underwear I’ve worn before.

Seamless: The comfort band and seamless design of the Essential Thong improves comfort and makes it so panty lines don’t show

Ethical business practices: Branwyn has taken a lot of effort to keep all aspects of their business as sustainable as possible, something that I value in any company.


Expensive: At $30 for one pair of underwear, the Essential Thong is relatively pricey. However, it’s reasonable compared to similar merino products. It’s also the cheapest of all Branwyn’s products.

Not recommended for the dryer: One of the downfalls of merino is that it can’t go in the dryer (usually it will shrink). It’s another item I have to remember to take out and air dry every time I do my laundry. On the plus side, the thong at least dries quickly.

Photo: Branwyn

Unflattering: I liked the fit of the Essential Thong, but I felt the way it hugged my hips wasn’t the most flattering. This is a personal preference and was inconsequential when compared to its benefits.

Overall Value

For a quality pair of merino underwear, these are a great option and value. Not only are they comfortable and functional, but they also come from a company with values worth supporting. I can see these being my go-to underwear for all my active needs for the future.

Shop the Branwyn Essential Thong

Comparable Products

Branwyn Essential Bikini

MSRP: $38
Materials: A GLDNspun knit blend of 81% extra fine merino wool, 12% nylon, and 7% spandex

Ibex Women’s Natural Thong

MSRP: $30
Materials: 83% merino wool, 12% nylon, 5% elastane

Exofficio Women’s Everyday Thong

MSRP: $20
Materials: 95% Viscose, 5% Elastane, Jersey, 150g/sqm

The Branwyn Essential Thong was donated for the purpose of review.

Affiliate Disclosure

This website contains affiliate links, which means The Trek may receive a percentage of any product or service you purchase using the links in the articles or advertisements. The buyer pays the same price as they would otherwise, and your purchase helps to support The Trek's ongoing goal to serve you quality backpacking advice and information. Thanks for your support!

To learn more, please visit the About This Site page.

What Do You Think?