Side view of the Light Nude BRANWYN Essential Thong, seamless underwear made from Merino wool for travel and everyday.
Back view of the Light Nude Essential Thong, seamless Merino wool thong underwear for women.
Side view of the Light Nude Essential Thong, a temperature-regulating, odor-resistant Merino wool travel thong.
Woman in the Light Nude Essential Thong, moisture-wicking natural fiber seamless underwear.
Woman jumping in the Light Nude Essential Thong, OB-GYN recommended underwear made from Merino wool.
Side view of the Dark Nude Essential Thong, a comfortable Merino wool thong for outdoor adventure and everyday.
Front view of the Dark Nude Essential Thong, a sweat-wicking Merino wool thong made to keep you dry.
Woman posing in a Dark Nude BRANWYN bra and Essential Thong, seamless underwear made from Merino wool.
Woman in the black Essential Thong, seamless, breathable underwear made from Merino wool.
Back view of the black Essential Thong, a low-profile seamless thong made from Merino wool.
Side view of the black Essential Thong, sweat-wicking Merino wool underwear for exercise, hiking, and active women.
Woman in the Warm Nude Essential Thong, BPA- and PFAS-free underwear made from natural fiber Merino wool.
Back view of a Warm Nude bralette and Essential Thong, a Merino wool thong for hiking and outdoor adventure.
Detail of the Warm Nude Essential Thong, soft seamless Merino wool underwear that stretches and moves with you.
Side view of the Luna Gray Essential Thong and matching bralette, seamless Merino wool thong underwear.
Luna Gray Essential Thong with bralette, seamless underwear made from breathable Merino wool.
Luna Gray BRANWYN Essential Thong, soft, moisture-wicking seamless underwear made from Merino wool.
Side view of a woman seated in the Luna Gray Essential Thong, soft, stretchy, naturally antimicrobial underwear.
Detail of the Future Dusk purple Essential Thong, soft, breathable seamless Merino wool underwear.
Woman in the Future Dusk Essential Thong and bralette, seamless performance underwear made from Merino wool.

Essential Thong

$36.00 USD
387 reviews
387 reviews
Merino wool benefits listed with icons: [Sheep icon] Merino wool = Sweat free freshness [Knit icon] Seamless knit = Second skin comfort [Sustainability icon] ZQ Merino = Ethical and sustainable fiber
BRANWYN Merino wool Essential Thong Underwear size guide slider.
Color:Black
Size:XS
Quantity:
In stock — only 3 left

Underwear Size Guide

All our knitwear has a lot of stretch, so you might be able to wear two different sizes. If you are unsure, size up.

WAIST HIPS PANT
XS 23 - 24 32 - 34 0 - 2
S 24 - 26 34 - 36 2 - 4
M 26 - 28 36 - 38 6 - 8
L 28 - 30 38 - 40 10 - 12
XL 30 - 32 40 - 42 12 - 16
XXL 32 - 34 42 - 44 16 - 18

Tell me more about the fit

Our Performance Innerwear is meant to fit snugly on the body. If you prefer a looser fit, we recommend sizing up. If it feels just a little tight and you aren't sure if the next size up would be better, then we recommend wearing and washing a few times to see if it breaks in to your liking before exchanging it for another size.

Will it stretch out?

Not really. Our Performance Innerwear does give a bit with wear, but instead of becoming loose, it will mold to your body more over time.

Underwear Size Guide

All our knitwear has a lot of stretch, so you might be able to wear two different sizes. If you are unsure, size up.

WAIST HIPS PANT
XS 23 - 24 32 - 34 0 - 2
S 24 - 26 34 - 36 2 - 4
M 26 - 28 36 - 38 6 - 8
L 28 - 30 38 - 40 10 - 12
XL 30 - 32 40 - 42 12 - 16
XXL 32 - 34 42 - 44 16 - 18

Tell me more about the fit

Our Performance Innerwear is meant to fit snugly on the body. If you prefer a looser fit, we recommend sizing up. If it feels just a little tight and you aren't sure if the next size up would be better, then we recommend wearing and washing a few times to see if it breaks in to your liking before exchanging it for another size.

Will it stretch out?

Not really. Our Performance Innerwear does give a bit with wear, but instead of becoming loose, it will mold to your body more over time.

Where it all started: our seamless Merino wool Essential Thong underwear has a low profile and a barely-there feel. Knit from super-fine 81% 17.5-micron ZQ+™ Merino wool, it keeps you fresh, dry, and funk-free from your first coffee to your last mile.

The soft, no-dig waistband won’t roll, so there are no lines and nothing to adjust, even on your longest adventures and toughest workouts. It’s so comfortable, you’ll forget it’s on.

Bonus: Our ZQ+™, Woolmark™, and RWS-certified GLDNspun™ seamless Merino wool is also regenerative and sustainable. 

Double Bonus: Virtually invisible under leggings and base layers, our Essential Thong feels like a second skin and stays put as you bend, squat, and stretch.

For more, scroll down to check out our customers' reviews!

COMPLETE THE SET

Woman in a black BRANWYN seamless Merino wool bralette, a soft natural fiber bra for everyday wear and activewear. Close-up of a black seamless Merino wool bralette as a woman raises her arms, natural fiber bra by BRANWYN.
Essential Bralette
$52.00 USD
Front view of the black Racerback Sports Bra, a seamless Merino wool compression sports bra that wicks sweat on hikes. Back detail of the black Racerback Sports Bra, a heavyweight, compressive seamless Merino wool knit that's breathable.
Essential Racerback Sports Bra
$85.00 USD

PERFORMANCE WITHOUT COMPROMISE

Designed for superior performance and maximum comfort—it all starts with Merino wool. Super-soft, ultra-fine Merino wicks sweat to keep you dry, fresh, and funk-free. The natural crimp of its fiber traps air so you stay cool when things heat up and keep warm when there’s a chill.

Moisture wicking

Naturally breathable

Temperature regulating

Benefits of Merino wool icon: Odor-resistant quality of seamless Merino wool

Odor Resistant

BUTTERY SOFT NATURAL FIBER

GYNECOLOGIST APPROVED