Side view of BRANWYN Essential Bikini Merino underwear in warm nude. Soft, breathable, and odor resistant, sustainable underwear.
Warm nude Merino bikini panties by BRANWYN. Made from regenerative Merino wool to provide a sustainable solution for eco-conscious women.
Back view of Merino bikini style underwear in warm nude. BRANWYN's Essential Bikini is made of super soft, knit, seamless Merino wool for ultimate comfort.
Woman in Merino warm nude underwear set from BRANWYN. The women's Essential Bikini is perfect for hiking, yoga, and gym sessions with moisture wicking comfort.
Close up of warm nude Essential Bikini underwear from BRANWYN. This Merino Wool underwear is temperature regulating perfect for everyday comfort.
Woman smiling and posing in Merino Innerwear set from BRANWYN in warm nude colorway. Designed for women by women for natural everyday comfort.
Back view of light nude Essential Bikini underwear and matching bra by BRANWYN Innerwear. Seamless women's underwear designed for comfort.
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Side profile of BRANWYN Essential Merino wool Bikini underwear in Luna Grey. Gynecologist recommended underwear made of natural fibers.
BRANWYN Grey Merino Wool Bikini Underwear—seamless, soft, sustainable, and twice as durable as synthetic underwear.
Back view of BRANWYN Essential Bikini Underwear made of sustainable Merino. Naturally toxin and forever chemical free women's underwear.
Women stretching grey Merino underwear. Sweat wicking, breathable, Merino underwear that moves with you and supports you for active women.
Back view detail of bikini underwear waistband in Luna grey Merino Wool. BRANWYN's Essential Bikini is completely seamless making it comfortable and chafe free.
Woman doing yoga in grey BRANWYN Merino bra and underwear set. Breathable Essential Bikini underwear is quick drying and keeps you fresh for workouts.
Close up of soft, comfy, seamless Merino underwear in the bikini style by BRANWYN in black.
Side view of BRANWYN Essential Bikini Merino underwear in black. Made of natural fabric free from BPAs, PFAs and forever chemicals.
Woman stretching in black Merino wool underwear set. The seamless design makes these a comfortable, stretchy, wedgie free underwear.
Close up of BRANWYN's black Essential Bikini underwear. Gynecologist approved Merino wool underwear made of natural, sustainable knit fabric.
Back view of the comfiest Merino bikini style underwear in black with full coverage bikini style, seamless design and breathable Merino wool.
Side view of BRANWYN's Essential Bikini underwear in black. Made of  Merino wool this underwear is odor reducing, easy to wash and perfect for travel.
Woman sitting and stretching in black BRANWYN Merino underwear set. Active underwear perfect for yoga, stretching, pilates, and workouts.
Front view of dark nude Essential Bikini underwear, full coverage Merino wool panties for everyday wear.
Back view of the best travel underwear. BRANWYN's Essential bikini in dark nude is perfect for on the go with odor reducing and mositure wicking Merino wool.
Dark nude brown BRANWYN Merino wool bra and panties set on woman standing, sustainable toxin-free underwear made of regenerative materials.
Woman wearing dark nude brown BRANWYN Essential Bikni underwear and matching bra, showing seamless design.
Back view of woman with curly hair smiling in BRANWYN seamless Merino wool bra and underwear set in dark nude brown
Woman posing in dark nude brown Merino underwear set, wearing BRANWYN Essential Bikini underwear made from soft, moisture wicking natural fibers.
Woman in BRANWYN Essential Bikini underwear set, side view, made of breathable Merino wool for active women and outdoor adventures.
Athletic woman wearing the BRANWYN Essential Bikini underwear in light nude. Merino wool underwear designed for activity with breathable knit and sweat wicking wool fabric.
Close up of BRANWYN Essential Bikini underwear in light nude. These Merino panties stay dry with breathable, mositure wicking Merino.
Stretching woman wearing BRANWYN Merino wool underwear designed to wick sweat, stay dry, and remain breathable.
Woman stretching in Merino wool athletic underwear by BRANWYN, sweat wicking and temperature regulating comfort no matter the movement.
Woman in three legged dog yoga pose in matching light nude BRANWYN Merino Wool underwear set.
Front view of woman in BRANWYN Essential Bikini underwear in light nude Merino wool, sustainable and breathable for active women.
Back view of BRANWYN Essential Bikini underwear in light nude, seamless Merino wool bra and panties designed for comfort and performance.
Side view of woman wearing BRANWYN Essential Bikini underwear and matching bra in light nude Merino wool. Seamless underwear that is naturally soft and moisture-wicking.
Woman posing with arms raised overhead in BRANWYN women’s seamless Merino wool bikini underwear set in light nude.
Front view of BRANWYN Essential Bikini Merino Wool underwear in Future Dusk purple. Showing seamless full coverage panties with stretchy waistband.
Front view of BRANWYN Essential Bikini underwear in Future Dusk purple. Sweat wicking underwear made of breathable Merino wool, to keep you feeling fresh.
Back view of BRANWYN Essential Bikini underwear full coverage seamless panties in Future Dusk purple.
Woman posing in Merino underwear set, wearing BRANWYN Essential Bikini underwear in Future Dusk purple. Eco-conscious underwear made of regenative natural fibers.
Close-up detail of BRANWYN Essential Bikini underwear in Future Dusk purple Merino wool, seamless and breathable underwear made of natural fibers

Essential Bikini

Sale price$38.00 USD

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.

Our Essential Bikini is designed to stay put and move with you, while keeping you funk-free, dry, and comfortable throughout your entire day no matter your adventure. Crafted from super-fine Merino wool, our seamless design and comfort waistband eliminate digging and rolling during your hike, ride, climb, workout, or vinyasa — so comfortable, you’ll forget you’re even wearing it!

Bonus: Our ZQ, OEKO-TEX, and Responsible Wool Standard certified Merino is also regenerative and sustainable. (which also means it is free of BPA, PFAs, and toxic forever chemicals).

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!

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

Odor Resistant

BUTTERY SOFT NATURAL FIBER

GYNECOLOGIST APPROVED

Customer Reviews

Based on 852 reviews
88%
(749)
11%
(91)
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L
Lauren Philp (Richmond, US)
WIDE GUSSET 👏🏼👏🏼👏🏼

This is my favorite underwear ever and ESPECIALLY for pregnancy and postpartum because of the WIDE GUSSET that helps me feel clean, dry, and like I can take proper care of myself when I need extra TLC. Yes it runs small and I'm happy that the size range has increased.

P
PNW Stephanie (Portland, US)
Great but run small

I’ve worn merino underwear from Icebreaker for a long time. I prefer these, as they are more pliable & less noticeable on. I have worn the Branwyn busty bras for over a year. They’ve held up well. I prefer the coverage of the busty because they stay put. I have ended up wearing them EVERY day because they’re so comfortable, so I decided to try the underwear a few months ago. They’re great. I don’t worry about lines, they’re so breathable, & they don’t really creep.

Be aware that they run SMALL. I’m 5’5”, 116# & comfortably wear a medium in the bikini underwear. For reference, I’m usually a small or xs (occasionally xxs) in clothing.

I always wash in cold water & hang dry. The other day I noticed that the Branwyn bikini undies dried in about half the time as Paka bikinis, which makes them even better for travel.

K
Kate Skinner (Auburn, US)
Best undies!

Of course the fabric is wonderful and very comfy! No tight elastic yet covers the bun! I bought the small but I bet I could do the xsmall too. I’m 5’2” 109 lbs for reference!

E
Elizabeth Como (Cambridge, US)
Comfy underwear

Fits well, feels great on my body

J
Jay (Lake Stevens, US)
I'm so sad to say this... but it's not worth the money...

Let me start by saying I love this product, and if they were half the price, I would just keep my mouth shut and buy more. Over the past two years, I have purchased many of both the essential bikini and essential bras, replacing all my undergarments. However, within this time, the band stitching has come undone on all of the underwear, and the elastic in the straps of my bras is starting to warp. The stitching at the end of one of the straps has even come undone. These are expensive panties, I want them to last, so I wash everything in an undergarment bag on delicate. I have not reported this to customer service, as I'm sure it's outside of any warranty, but be warned, these garments do not last.

MONEY BACK GUARANTEE FOR 14 DAYS

Not sure about wool?

Merino is super soft like cashmere!

We know you'll love it! But just in case you don't, we’ll give you a full refund.