Free 2-Day Shipping on Orders Over $50* - Limited Time Only

Wool underwear? No, we’re not kidding. The I/O Bio Women's Contact 1 Boy Brief’s silky-smooth Enigma knit caresses your nether-regions with never-itchy, naturally anti-odor, and super-soft merino wool. A touch of elastane ensures that it doesn’t sag or bag, and the wide elastic waistband stays put without digging. Out on the trail, skiing the steeps, or every day, these boy-cut undies offer killer comfort.

Share your thoughts

What do you think of the

I/O Bio Merino Contact Boy Brief - Women's

? Share a...

Write a review

No file chosen

Rather attach a photo from another website?

Rather attach a photo from your computer?

    Add a:
  • Share a photo
  • Share a video


Product Fit:

Add Your Size

in cm

Height (ft, in):

Weight (lbs):

Size Purchased:

Only jpg, jpeg, png, gif or bmp files please.

Submit Cancel
Now review from the App. Download

Here's what others have to say...

4 5

A lil' different from the Icebreaker one

I found these on crazy sale so I figured that maybe they are like the Icebreaker Sprite Hot Pants (which I love) since they look almost exactly alike and went for it. I got the size S. The main noticeable difference is that the leg openings on these bottoms are a little tight, but they aren't too constricting so its still wearable. I have muscle-y thighs, which I've noticed can be an issue when getting boy shorts-type underwear, but I don't have this problem at all with the Icebreaker ones.

5 5


I own them in lime (two pairs), pink and orange. I'd snag the black too if they'd ever get them in medium! They wash and wear great. Stay put and are very flattering. I need more pairs!

4 5

Not for me, but pretty nice

I have fuller thighs and found these to bind at the leg openings, it wasn't so bad that I couldn't stand it but I didn't want to chance getting chaffing in a sensitive area. Other than that they were a great fit in every other way. I really love the I/O sport bras and wished I could have kept these undies to have a matching set, but oh well.

5 5

i/o bio merino contact boy brief

Love these when I ski. comfy and keeps my bottom warm.
too bad my size is sold out.

5 5


Just right coverage. I am 5-5 140 and wear med. (38" hip). They wash nicely but no dryer. Just lay flat. I am very happy with the fit and the feel.

Can anyone comment on the rise? They look...

Can anyone comment on the rise? They look like low rise in the pics. I'm looking for something with a medium rise.

I consider them a medium rise. Definitely not waist high, but fit is about 3-3 1/2" below navel and just above the wide part of my hips on me. (5-5 and 140 lbs)

I would definitely say mid-rise. The newest ones are about an inch lower in the rise than the prior generation, but still mid. The cool part is that they are made of stretchy merino so you have a little more wiggle room as far as rise anyhow...

The past two seasons brief is lowrise.. Loved the old fit! I have a big but, and these will not really stay put, I have to pull up to often... but as I said, I have a big but (108cm seat 78cm waist). If your but is more average you should be better than fine whit these! Despite the 'update' of these, they are still my absolute favorite.

i guess it depends on your definition of *low* and *mid* rise and your unique body. i am 5'10" and 130lbs. i bought the size small in these and they fit perfect. the waistband sits at 3 1/2" below my navel. i get full coverage in the back thanks to the wide waistband. super cute, super comfy whether you call them low or mid rise...

5 5

Once you go Merino you will never go back

I have never cared much about what I wear in terms of underwear on a ski day. Lace to cotton, thong to grannies I have warn it all in the backcountry, however now that I have gone Merino I will never go back! These are not only soft, but they keep EVERYTHING nice and dry and the cut is super comfy so you aren't left trying to adjust yourself when you should be dropping that line. If you are looking to treat yourself to something really great, you want to treat yourself to some I/O BIO briefs!

5 5


Very soft to the touch, the wool couldn't be softer, not itchy at all. Wears and washes well. and they look cute too. would buy more in different colors, cause i keep reaching for them not only for sports. great product.

5 5

Comfy and Cute!

These are some of the most comfortable underwear I've worn. You don't realize you're wearing them until it's time to take them off. I find myself reaching for these over other underwear for more than just sports. Super soft and not itchy at all, and they are super cute!