Side view of the Warm Nude Essential Bikini, seamless underwear made from soft, breathable, odor-resistant Merino wool.
Front view of Warm Nude bikini underwear by BRANWYN, natural fiber seamless underwear made from Merino wool.
Back view of the Warm Nude Essential Bikini, soft knit seamless Merino wool underwear for all-day comfort.
Woman in the Warm Nude Essential Bikini, moisture-wicking Merino wool underwear for hiking, yoga, and travel.
Woman with arms crossed in the Warm Nude Essential Bikini, temperature-regulating seamless Merino wool underwear.
Woman smiling in a Warm Nude BRANWYN bra and Essential Bikini, breathable natural fiber underwear.
Back view of the Light Nude Essential Bikini and matching bra, seamless underwear made from Merino wool.
Woman smiling in the BRANWYN Bralette and Essential Bikini, breathable seamless Merino wool underwear for women.
Side view of the Luna Gray Essential Bikini, OB-GYN recommended underwear made from natural fiber Merino wool.
Luna Gray Merino wool bikini underwear by BRANWYN, soft, durable seamless underwear.
Back view of the Luna Gray Essential Bikini, BPA- and PFAS-free seamless underwear made from Merino wool.
Woman stretching the Luna Gray Essential Bikini waistband, sweat-wicking, breathable underwear for active women.
Waistband detail of the Luna Gray Essential Bikini, chafe-free seamless underwear made from Merino wool.
Woman in a yoga pose in a Luna Gray bra and Essential Bikini, quick-drying Merino wool underwear for workouts.
Close-up of the black Essential Bikini, soft and comfortable seamless underwear made from Merino wool.
Side view of the black BRANWYN Essential Bikini, seamless Merino wool underwear made from breathable natural fiber.
Woman stretching in a black Merino wool underwear set, stretchy, wedgie-free seamless underwear by BRANWYN.
Close-up of the black Essential Bikini, OB-GYN recommended seamless underwear made from natural fiber Merino wool.
Back view of the black Essential Bikini, full-coverage seamless underwear made from breathable Merino wool.
Side view of the black Essential Bikini, breathable Merino wool travel underwear for women.
Woman seated in a stretch in a black BRANWYN set, Merino wool underwear for yoga, Pilates, and workouts.
Front view of the Dark Nude Essential Bikini, full-coverage seamless Merino wool underwear for everyday wear.
Back view of the Dark Nude Essential Bikini, odor-resistant, moisture-wicking Merino wool travel underwear.
Woman standing in a Dark Nude BRANWYN bra and Essential Bikini, a natural fiber seamless underwear set.
Woman in the Dark Nude Essential Bikini and matching bra, showing the seamless Merino wool design.
Back view of a woman with curly hair in a Dark Nude BRANWYN seamless Merino wool bra and underwear set.
Woman with silver hair in the Dark Nude Essential Bikini, soft, moisture-wicking natural fiber underwear.
Side view of the Dark Nude Essential Bikini, breathable Merino wool underwear for active women and adventures.
Athletic woman in the Light Nude Essential Bikini, sweat-wicking Merino wool underwear designed for activity.
Close-up of the Light Nude Essential Bikini, breathable, moisture-wicking seamless underwear made from Merino wool.
Back view of a woman stretching in the Light Nude Essential Bikini, Merino wool underwear that wicks sweat.
Woman stretching in the Light Nude Essential Bikini, temperature-regulating Merino wool underwear for every move.
Woman in a three-legged dog yoga pose in a Light Nude BRANWYN Merino wool underwear set.
Front view of the Light Nude Essential Bikini, breathable seamless underwear for active women.
Back view of the Light Nude Essential Bikini and bra, seamless Merino wool underwear for comfort and performance.
Side view of the Light Nude Essential Bikini and bra, naturally soft, moisture-wicking seamless underwear.
Woman with arms raised in a Light Nude Essential Bikini set, seamless underwear made from Merino wool.
Front view of the Future Dusk purple Essential Bikini, full-coverage seamless Merino wool underwear.
Woman in the Future Dusk Essential Bikini, sweat-wicking underwear made from breathable Merino wool.
Back view of the Future Dusk Essential Bikini, full-coverage seamless underwear made from Merino wool.
Woman posing in a Future Dusk BRANWYN set, naturally antimicrobial Merino wool bikini underwear.
Close-up of the Future Dusk Essential Bikini, breathable seamless underwear made from natural fiber Merino wool.
Front view of the Transformative Teal Essential Bikini, seamless Merino wool underwear made from breathable natural fiber.
Side view of the Transformative Teal BRANWYN Essential Bikini, seamless underwear made from Merino wool.
Back view of the Transformative Teal Essential Bikini, odor-resistant seamless Merino wool underwear.

Essential Bikini

$38.00 USD
1120 reviews
1120 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 Bikini Underwear size guide slider.
Color:Black
Size:XS
Quantity:
In stock

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.

The Essential Bikini seamless Merino wool underwear stays put and moves with you through every twist and turn. Seamlessly knit from super-fine 17.5-micron 81% ZQ+™ Merino wool, it keeps you dry, comfortable, and funk-free all day, whatever your adventure.

The seamless design and soft, no-dig waistband won’t roll or ride up on your hike, ride, climb, workout, or vinyasa. It’s so comfortable, you’ll forget you’re wearing it.

Bonus: Our ZQ+™ and Responsible Wool Standard-certified Merino wool is also regenerative and sustainable. 

Double Bonus: Our Bikini is great in and around the water. It dries in the blink of an eye.

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