Free 2-Day Shipping on Orders Over $50* Up to 25% Off Marmot– Save on Clothing and Gear


Pull on the Marmot microfleece Reactor Pant for an extra layer in between you and the cold.

Whether you’re stuck in the cold or in the cold for fun, the Marmot Reactor Pants keep you warm. Enjoy the durable comfort of Marmot’s Polartec polyester microfleece midlayer and keep out the winter winds. Combine the Reactor with a waterproof shell when you find yourself neck-deep in powder in the backcountry, or wear them under your Carhartts on a chilly night around the campfire.

Share your thoughts



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


Height (ft, in):

Weight (lbs):

Size Purchased:

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

Now review from the App.Download

Here's what others have to say...


Comfy and warm

  • Familiarity:I've put it through the wringer
  • Fit:True to size

Nothing makes a cold winter day lounging around the house or lodge better than a comfy pair of fleece pants. These are legit!


very nice cold weather pants

  • Familiarity:I've used it several times
  • Fit:Runs large

100 weight fleece make a warm and comfortable pants. Layer under shell pants or layer over capilene base layer. Fits good at waist but a little baggie through the legs. Zip back pocket is great but the front pockets suck. To shallow to allow much inside. Side seam pockets would be a much better design.


Great base layer

  • Familiarity:I've used it several times
  • Fit:True to size

I use these when it's cold and I'm just in uninsulated 3 ply gore-tex bibs as a base layer. Perfect! Too warm if I'm in insulated pants. Just what I got them for. Great quality..


They changed them

  • Familiarity:I've put it through the wringer
  • Fit:True to size

I have owned a pair of these for a number of years, and recently ordered a pair as a replacement. But the new pair have side patch pockets, which is different from the side seam pockets on my original pair and as shown in the picture -- so I returned them. I also thought that the cut was baggier -- more like sweats than the original sleeker shape. They would still keep you warm, but not for me.


Best fleece pants ever

    They are very comfortable, not too warm - and the cut is perfect for myself (6'0" and usually wear longer inseams). The front pockets are a bit shallow but great for small items or warming your hands, and then the zippered back pocket is perfect for holding a few things (cell phone, keys, etc).

    Any pockets anywhere?

    Any pockets anywhere?

    Best Answer

    Yes there are pockets...two in the front and one back zip pocket

    hope this helps...

    do the marmot reactor fleece pants have a...

    do the marmot reactor fleece pants have a smooth exterior surface or a rough fleece exterior?

    They have a standard fleecy exterior, i.e. not a smooth face fabric.


    Best Jammies in the WORLD

      I have owned a pair of these for quite some time so after they started to wear a little thin I had to get another pair. They are great for backpacking, day hiking, or whatever ....mostly I wear them around the home at night. The zipper pocket is nice so my cash doesn't fall out. I am a size 34 waist and the large size fits me perfectly. They expand a little and have a draw string. Get em, you will luv them. These are a MUST for anyone that likes comfort in the backcountry!


      Just right

        I've worn these under ski pants for back country adventures, under my dry suit on 20 degree river paddles, and in my sleeping bag and around camp. After all of the beatings, soakings, stretching, and washings they don't look or work any different than they did out of the package. Picked up a second pair because I thought as much as I use them they wouldn't last and the second pair is still sitting in the packaging in the drawer. There has been minimal to no piling and not a stitch has moved. They are thick enough to be warm but thin enough to fit under most other garments even with lightweight tights on. I do miss having "front access" but not enough to wear something else. Highly recommended.

        Does the men's fleece ski underwear of...

        Does the men's fleece ski underwear of Marmot have a fly?


        Great for summit

          Wore these on summit night of Mt Kilimanjaro over some Burton thermals and under a light shell. Worked beautifully at 15 degrees and was very light.