REI Co-op Active Briefs - Women's
Made to move, the moisture-wicking, quick-drying REI Co-op Active briefs for women are your ticket to comfy on and off the trail. Designed for people who like to move.
- Briefs style features a higher rise and longer outseam than our Active Bikini and Active Hipster underwear
- Stretchy polyester mesh is constructed with minimal seaming and trim details
- Moisture-wicking and quick-drying after sweating or washing
- Pairs with REI Co-op Active bralette (not included)
- Machine wash warm; use only non-chlorine bleach, when needed; tumble dry low
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
Imported.
View all REI Co-op Women's BriefsBest Use | Multisport |
---|---|
Underwear Style | Brief |
Fabric | 86% polyester/14% spandex mesh |
Moisture Wicking | Yes |
Quick Drying | Yes |
Gender | Women's |
Sustainability | From a Climate Label Certified brand |
XXS | XS | S | M | L | XL | 1X | 2X | 3X | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18W | 20W | 22W | 24W | 26W | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Numerical Size | 00 | 0-2 | 4-6 | 8-10 | 12-14 | 16 | 18 | 20-22 | 24-26 | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | 26 |
Bust | 31 | 32-33 | 34-35 | 36-37 | 38.5-40 | 41-42.5 | 43-45 | 47-49 | 51-53 | 32 | 33 | 34 | 35 | 36 | 37 | 38.5 | 40 | 42.5 | 45 | 47 | 49 | 51 | 53 |
Sleeve Length | 29.5 | 30 | 30.5 | 31 | 31.5 | 32 | 32.5 | 33.5 | 34.5 | 30 | 30 | 30.5 | 30.5 | 31 | 31 | 31.5 | 31.5 | 32 | 32.5 | 33.5 | 33.5 | 34.5 | 34.5 |
Waist | 24.5 | 25.5-26.5 | 27.5-28.5 | 29.5-30.5 | 32-33.5 | 34.5-36.5 | 37.5-39.5 | 40.5-42.5 | 44.5-46.5 | 25.5 | 26.5 | 27.5 | 28.5 | 29.5 | 30.5 | 32 | 33.5 | 36 | 38.5 | 40.5 | 42.5 | 44.5 | 46.5 |
Hip | 34 | 35-36 | 37-38 | 39-40 | 41.5-43 | 44-46 | 47-49 | 50-52 | 54-56 | 35 | 36 | 37 | 38 | 39 | 40 | 41.5 | 43 | 45.5 | 48 | 50 | 52 | 54 | 56 |
Inseam | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements. Some women's pants are available in petite and tall sizes. Typically petite sizes fit women 4'11" to 5'3". Regular sizes fit women 5'4" to 5'8". Tall sizes fit women 5'9" to 5'11".
PETITE: Generally, as compared to regular sizes, petite sizes are 2.5 inches shorter in inseam, 1 inch shorter in body length, 1.25 inches shorter in sleeve length and ¾ inch shorter in total rise.
TALL: tall sizes are 3 inches longer in inseam, 2 inches longer in body length, 2.5 inches longer in sleeve length and 1.25 inches longer in total rise.
Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.
Inseam is measured to the floor.
Better gear is built together
From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.


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Newer version runs very large
The newer version in the jasper green color runs large compared to previous versions in the same size. I hesitate to purchase more as replacements when the XS is so much larger than it used to be. I'm bummed out because this active line has otherwise been my absolute favorite underwear for hiking the last several years.
The cotton gusset is gone!
The original version of these underwear was my favorite of all active brands/styles/materials I have tried over the years. They were incredibly lightweight, did not budge and dried in a flash. It was like wearing nothing with essentially no visible lines, even under leggings. Then came version 2.0 which suffered from major durability issues and the inclusion of a cotton gusset that bunched awkwardly and was the opposite of quick drying. This version appears to finally be back to the original template. I can't speak to long-term durability yet but fabric and fit seem to be just like my original pairs in initial wearing. Those pairs are still going strong after 3 years of constant use. One note is that, as always, the color range on these is limited and these are unlikely to provide a true nude color for any skin tone. If that is not a concern, they're a great option for hiking, camping and travel.
Buyer Beware!
I’m a longtime fan of REI’s briefs - my previous pairs were super durable, fast drying & flattering - my go-tos for hiking, travel, etc. Unfortunately, they’re no longer widely available, but I thought I’d lucked out when I found a few pairs being offered through REI Outlet. Too bad I didn’t read the most recent reviews! The four pairs I recently purchased bore only a superficial resemblance to my previous ones. The stitching in the waistband wasn’t stretchy. In one pair it ripped out the first time I tried them on. All four pairs were a size small, yet the sizing between them varied widely. And even though I bought them through the outlet, they were still over $15 a pair. Not sure what happened to quality control? I’d return them, but I cut out the tags before I realized the issues. Don’t make the same mistake!
Comfy and Stays Put
I’m very picky about underwear. My butt seems to eat underwear for breakfast, lunch and dinner. I just can’t seem to keep from getting a wedgie and I don’t like wearing thongs. These underwear stayed put all day! No wedgies. And they’re soft and light.
Please keep making this underwear REI!
This is the only underwear I've ever had that is always comfortable and never gives me a wedgie. So comfortable and perfect for moving around and being active. PLEASE restock these REI, I'm desperate to buy more!
size down - these stretch out
I bought these using the size guide and was quite disappointed with the fit. I had the old active briefs and they had a nice seamless no VPL fit. These stretched out after one use. They are comfortable but probably not what I would choose on a long hike.
Plz keep making these....
PLEASE DON'T STOP MAKING THESE. These are the only underwear that don't give me a wedgie. Please.
why are these NEVER in stock???
These stay so dry when I’m exercising. Huge help. I love them. And they stay out and don’t ride up. And they contain my ample butt. I want more!!!!!
the best underwear but never in stock
I wish these were consistently in stock. How hard is it to supply underwear??
Do not buy these.
I bought two pairs of these to wear when walking and hiking through the mountains of France (the Chemin du Puy). One pair fell apart after just a week. Completely fell apart. I was left with one pair of knickers that were slowly falling apart for the next 6 weeks. Finding plus size anything in France was impossible. Do not buy these. They will let you down.