Men's Merino Running Briefs | Runderwear™ – Runderwear AU

Men's Merino Running Briefs - ADD ANY 3 ITEMS TO YOUR BAG SAVE 15%* more


Seamless Men's Running Briefs enhanced by the magic of Merino. Experience unrivalled comfort and performance.

  • Responsibly sourced, sustainable Merino with seamless design
  • Naturally regulates temperature in any conditions
  • Anti-bacterial, odour-resistant and removes sweat quickly
  • Super-fine, ultra-soft and non-itchy against the skin
  • As with all Runderwear products: Chafe-free, guaranteed


  • S
  • M
  • L
  • XL
  • XXL

Colour: Grey

  • Grey
Runderwear Men’s Merino Running Briefs are designed to deliver unrivalled comfort and performance. All the features of our classic Men's Running Briefs - seamless design, breathable, moisture-wicking and of course, chafe-free - enhanced by the magic of Merino; the world's best natural performance fibre


Merino wool comes from Merino sheep, who face scorching hot summers and bitterly cold winters in their natural Australian mountain habitat. As a result, their wool has evolved to have unmatched levels of temperature control - so our Merino range will keep you at the perfect temperature in any conditions

This intelligent, organic fibre also absorbs both odour-causing bacteria and moisture from your body, quickly. It traps the bacteria to make it odour-resistant and it can absorb up to 35% of its own weight before feeling wet, meaning you stay fresh and dry on your run

To prevent overheating the sheep are sheared once a year, so the fibre is sustainable and renewable. The fineness and softness of Merino is measured in Microns – at 18.5 Microns, Runderwear Merino is super-fine – making it ultra-soft and non-itchy against your skin

Fabric Composition:

45% Merino Wool
40% Polyester Thermocool™
10% Polyamide
5% Elastane

Product Care: 

  • Warm machine wash up to 40°C
  • Wash with similar colours
  • Do not tumble dry
  • Do not soak, bleach or dry clean
Size Guide
CMs 76-81 81-86 86-91 81-96 96-101
INCHES 30-32 32-34 34-36 36-38 38-40

Rundercare Help and Advice:

If you need any help or advice, you can contact our Customer Care team, they would love to hear from you!


Runderwear™ Delivery:

FREE delivery in Australia and New Zealand on all orders over $70

Australia & New Zealand

  • FREE delivery (Australia Post Parcel) on all orders over $70
  • For orders under $70 delivery is $9.

Black Friday & Christmas Delivery

We know that delivery services in the US are busier than usual at the moment during this busy period.

Please be patient whilst our delivery partners work as hard and fast as they can to deliver your order to you.

Runderwear™ Returns:

You can return any Runderwear™ Socks, Crop Tops, Support Bras, Base Layers to us within 14 days of purchase and can request a full refund or a product exchange.

Due to hygiene reasons we can not accept returns on underwear including Briefs, Hipsters, G-Strings, Hot Pants, Boxer Shorts and Tri Suits, if they have been worn.

In the unlikely event that your product becomes faulty, you may return your purchase for a full refund or exchange.

Please package your return appropriately and add in a note to let us know whether you require a refund or product exchange. Please pay the postage in full and send to our Rundercare team at the following address:

Runderwear™ Returns
PO Box 5090

Please email our Rundercare team at if you require any further help.

Customer Reviews

Based on 66 reviews
Stuart Hatcher
Just the best rundies you can buy

these are quite simply the best running underwear item that you can buy and that i have owned and tried. they will last and last as a high quality high performance but of kit, the merino is a great addition to running briefs as it helps wick away and keep you dry. i've used these for marathons and ultra marathons and the performance levels as against other underwear over these distances are superior. there is a lot of great running underwear out there now, but if i was to hands down be asked for 1 recommendation only it would be these. yes there are expensive (the 3 pack makes them almost affordable...) but you get the sense of why they are after using them for a while, and as i say, they will last so the overall investment cost is probably better than inferior product and when you factor in comfort, well, who wouldn't pay any price for that. they feel great, no itching or scratching or chafing and wash up well. just the best rundies you can buy imho.

Thankyou for your lovely feedback, Great to hear that you are loving the Runderwear Merino Briefs and they are the best that you have tried. We love to hear this! Thankyou for your purchases with Runderwear!

George Buckley
Freed from lubricant

So, with a degree of trepidation, I went lubeless……..ultra training, long runs and no Vaseline, super lube or other greasy paste on my bits!
I’ve completed a 65 mile training week, 2 twenty milers in successive days….with my runderwear merino briefs.
I’m delighted… chafing, no soreness and no need for any additional products.
As they say in my part of the world… absolutely wheeker!

Thankyou for your feedback, Great to hear that you are love the Men's Merino Briefs and your 65 mile training week wearing these went well. We love to hear it

Iain Martin
Somewhat disappointing ☹️

Well made briefs, but do not make it easy for a call of nature as you need to drop them a bit. Not really suitable for casual wear.
Wouldn't buy again or recommend.

Thankyou for your feedback, Really sorry to hear that you did not get along with the Runderwear Briefs. I will pass your feedback onto the team this is greatly appreciated.

Daniel Keedwell
Very Good

These are comfortable and well-made briefs, and are the perfect underwear for running in!

Julian Waldron
Nice and comfortable

Does what it says on the tin! Very comfortable to wear and have quickly become a firm favourite.

Buy any 3 items from across our store and save 15%.

Promotional discount codes can be used in conjunction with this offer except on Anti Blister socks.

Full details available here.

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