5.0
Had to return, which was an easy process. Wanted to buy a larger size but they were all out.
4/10/2026
Smartwool Apparel Size Guide Elevate your undergarment selection with the Smartwool® Merino Sport 150 Brief Boxed. Merino 150 fabric: • Core Spun yarns wrap merino wool fibers around a nylon core for a blend of natural and synthetic performance. • Merino wool offers a supremely soft, next-to-skin feel. • Moisture-wicking performance moves perspiration away from the skin. • Nylon core lends resiliency to the stretch for improved, durable recovery. • 150 g/m² / 4.42 oz/yd² fabric weight. 56% merino wool, 44% polyester. Machine wash, tumble dry. Imported. If you're not fully satisfied with your purchase, you are welcome to return any unworn, unwashed items in the original packaging with tags and if applicable, the protective adhesive strip intact. Note: Briefs, swimsuits and bikini bottoms should be tried on over underwear, without removing the protective adhesive strip. Returns that fail to adhere to these guidelines may be rejected.
Design: Black
Size: Choose a size
International delivery
Shipping calculated at checkout
Returns & exchanges
Within 30 days of delivery
Smartwool Apparel Size Guide Elevate your undergarment selection with the Smartwool® Merino Sport 150 Brief Boxed. Merino 150 fabric: • Core Spun yarns wrap merino wool fibers around a nylon core for a blend of natural and synthetic performance. • Merino wool offers a supremely soft, next-to-skin feel. • Moisture-wicking performance moves perspiration away from the skin. • Nylon core lends resiliency to the stretch for improved, durable recovery. • 150 g/m² / 4.42 oz/yd² fabric weight. 56% merino wool, 44% polyester. Machine wash, tumble dry. Imported. If you're not fully satisfied with your purchase, you are welcome to return any unworn, unwashed items in the original packaging with tags and if applicable, the protective adhesive strip intact. Note: Briefs, swimsuits and bikini bottoms should be tried on over underwear, without removing the protective adhesive strip. Returns that fail to adhere to these guidelines may be rejected.
- SKU
- 7-9526325
- Brand
- Smartwool
- Category
- mens / underwear
- Variants
- 6
Customer reviews
5.0
Super comfortable and great supportive fit
3/16/2026
5.0
New favorite: Super comfortable and great supportive fit
3/15/2026
4.0
My boyfriend got the black pair around Christmas 2025 in medium and he loves them. I recently got him the grey pair because he loved the black ones so much, but they are different. The sizing is weird, the waist is the same, but there is not really any support around the leg openings and his man-goods are hanging out the sides. I offered to return them but he thought maybe washing and drying would help, unfortunately that didn't help. He will still wear them, but they don't seem to be the same quality as the black ones from 2025. Not sure if all of them have changed, but I felt it was worth noting. We love everything else Smartwool and he is a huge fan of the boxer briefs.
2/22/2026
5.0
After decades of wearing Hanes briefs, I'm in the process of turning over my underwear to all merino wool. I bought a couple of pairs to test out. I found them to be comfortable, supportive, softer, and cooler. I guess I didn't know what I was missing, but now I do, so in with the new. Another 5 have been added to the collection, so I should be set for some time. Durability is the only unknown. Time will tell. 33" waist, and the Medium fits great. Snug how I like it, which I guess is the whole point of going with briefs. I thought I might miss the fly, but have learned to adapt. I'll take the more supportive design over easier access.
2/17/2026
5.0
Finally took the leap to smartwool briefs and should have done it before. Very comfortable which I had worried about. Really love how they compliment the base layer. In Minnesota it can be extremely cold and hot and humid. I've been experimenting with hand washing for travel and camping. Dry time is impressive. Another amazing smartwool product
1/27/2026
5.0
I needed something to go under my running tights. Athletic boxer briefs failed. These DELIVERED!
1/26/2026
3.0
As a long-time wearer of the Smartwool boxer brief, I decided to try out a couple pair of these. The flat-front design leaves no room for my manhood which made them uncomfortable to wear for extended periods of time. Seat coverage and materials are great. Designers just need to add a front pouch seam to give the goods room without squishing.
1/22/2026
4.0
I recently moved to a hot humid climate. My cotton underwear stayed wet most of the day if I did anything more active than just sit around. My merino wool underwear drys quickly, and is comfortable all day long. The only drawback - Smartwool chose to sew a long tag to the waistband.
1/22/2026
1.0
they tore at the waist band after the first wash and dry, even before i had a chance to wear them
12/12/2025
