Last Updated: December 14, 2022
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Osprey Mutant 38 Backpack Review: A Great Mountaineering Pack?


Osprey Mutant 38 Backpack

Specifically built with alpinists, climbers, and mountaineers in mind the Osprey Mutant 38 Backpack is a pack of note that makes life in the mountains that little bit easier. There is a space for all your gear which is easy to access, nothing gets in the way, the pack is super comfortable and supportive, plus you can dump weight when you need to, and lots more. View Latest Deal

If you are an alpinist or a climber who likes to push to summits having the right backpack for the journey is key to making your life up to the summit as easy as possible.

Having the ability to store all your gear in easy-access places that don’t get in the way, being able to shed parts of the backpack before pushing to the summit, and having space to store all the gear you need for an adventure is one thing.  

But your pack also needs to support you up the mountain, providing comfort and support for your body under the strain of a 4-5 day pack being carried across harsh terrains. Not many backpacks can live up to these kinds of demands but the Osprey Mutant 38 Backpack does just that.

Join me in our Osprey Mutant 38 Backpack Review you can find out why this is the backpack you want to carry when summiting mountains, crossing glaciers, and climbing crags. 


  • Very comfortable when fully loaded
  • Great value for money
  • Super durable
  • Has excellent features
  • Removable components
  • A spot for everything
  • A-frame ski-carry
  • Dual ToolLocks with bungee tie-offs
  • Glove-friendly buckles and zippers


  • Could be lighter

Product Rating

82Overall Rating
Materials & Durability
Comfort & Support
Weight & Volume
Value for Money

Product Information

  • Best Use: Mountaineering & Climbing
  • Frame Type: Internal Frame
  • Body Material: 210-denier nylon
  • Bottom Material: 420-denier nylon
  • Frame Material: Framesheet with aluminum stays
  • Number of Stays: 2
  • Reservoir Compatible: Yes
  • Pack Access: Top
  • No. Exterior Pockets: 1 + main compartment
  • Dimensions: 29 x 13 x 12 inches

Materials & Durability

The first questions I always ask myself when buying outdoor gear are, what is it made of and how long is it going to last? Especially when it comes to backpacks made for mountaineering.

There is never any reason to buy something that isn’t going to last as long as the next best product, so let’s see how the Osprey Mutant 38 Backpack does when it comes to its materials and durability.


The Osprey Mutant 38 Backpack is built from two different grades of material and this is to keep the weight down while ensuring the areas of the backpack that take the most wear remain durable.

Most of the Osprey Mutant 38 Backpack is made using 210 denier nylon and this is the most used density (210D) on backpacks of this kind.

But the Osprey Mutant 38 also adds a 420 denier nylon to the pack’s bottom to ensure that it can handle being placed on harsh surfaces like rocks and doesn’t wear through.

To put it into perspective, packs made for long expeditions are usually made from 420 denier nylon, so it is great that Osprey added this to the Mutant.


Thanks to Osprey’s well-thought-out design, they have dramatically increased the durability of the Mutant Backpack by adding the 420D nylon to the bottom of the pack.

This addition ensures that the mutant is going to last longer than most packs of this type but without compromising on the empty pack weight.

Mountaineers look to save every gram possible and there is always a balancing act to be played between material weight and durability, and I think Osprey has hit the nail on the head with the Mutant.

Comfort & Support

Osprey Mutant 38L Climbing and Mountaineering Unisex Backpack, Mars Orange, S/M

If your backpack isn’t comfortable to carry or doesn’t offer any support under a heavy load, you are going to sell it and look for a new one. And, this is even more important when it comes to climbing and summiting.

How good is the Osprey Mutant 38 Backpack when it comes to comfort and support?

Frame & Backpanel

The Osprey Mutant 38 features an internal aluminum frame with a well-padded back panel to ensure maximum carrying comfort.

The frame does a great job of evening out the weight distribution to ensure no single part of your body is overloaded while the padded back panel ensures no sharp climbing gear is stabbing you in the back while you hike.

Another great thing about this backpack is that you can remove the aluminum frame sheet when you want to dump weight before a final push to the summit, but you can leave the back panel in place for protection and comfort.

You can remove the foam from the back panel too and it is great for sleeping on, but your sharp gear will dig into you on your ascent.


The Mutant has a slim shape that conforms to your body to allow better natural movement as you ascend. You can move your hops well and this ensures you can climb far more efficiently and for longer.

Hip Belt

The hip belt included on the Mutant is quite narrow but well-padded meaning that it provides all the support you need for a full heavy pack but the narrow profile ensures it doesn’t get in the way when used in conjunction with a climbing harness.


Breathability is key to comfort on the mountains, especially when mountaineering in the summertime.

The Mutant is covered with super breathable fabrics that manage to wick moisture very quickly despite being very close to the body.

This means you won’t overheat and will be able to push harder on your climb.

Shoulder Straps

The shoulder straps are well padded and breathable but feature thin foam, which may be a little confusing for some.

The foam is thin but firm which aids the better movement of your body and when used with the sternum strap distributes the load very well.

Overall, the Osprey Mutant 38 Backpack is excellent when it comes to comfort and support!


Osprey Mutant 38L Climbing and Mountaineering Unisex Backpack, Tungsten Grey, S/M

For a backpack to be useful when mountaineering, you need it to have the right features so you can carry all the right gear and access it easily.

The Osprey Mutant 38 Backpack pretty much nails it when it comes to this and here is how.

Rope Carrying

The pack features a rope carrying system on the front of the pack which is a great addition as it makes carrying a rope, which you always need, very easy.

Having the rope on the front is a bit of pain though as it will get in the way of your ice tools unless you clip it in.

Helmet Carry

You will find a helmet carry system on the top of the pack which is great as it means you won’t damage the helmet when putting the pack down.

You can also add the helmet to the front of the pack if you want to but you do risk cracking it when you put your pack down. It also adds weight away from your center of gravity which affects your comfort.

That being said, it does allow you to carry your helmet when you have dumped your lid, which is an awesome feature.

Removable Lid & Flap Jacket

The lid is fully removable which is an awesome addition as it allows you to dump weight before the final push.

It also comes with a FlapJacket which you can deploy over the pack when the lid is removed so your gear is still protected from the elements.

Gear Attachments

There are loads of well-placed gear attachment points that are easy to access on this pack. You will find an ice clipper attachment sleeve, gear loops on the hip belt, an ice axe attachment system, plus a load more.

All the attachment points mean you can quickly get to what you need and they don’t get in the way while you climb either.

Ski/Crampon Attachment

The A-frame ski carry at the front of the pack is very handy and this doubles up as a place to carry your crampons too. You can also use the front helmet carry system in conjunction with this.

What’s Missing?

With the lid removed, you lose the zippered mesh pocket, so small things will move around and be harder to find.

The axe or tool carrying system also overlaps with the buckle closure system which is a bit of a pain.

Weight & Volume

Osprey Mutant 38L Climbing and Mountaineering Unisex Backpack, Tungsten Grey, S/M

Every gram is on the line when it comes to summits and climbing so it is important to own a backpack that weighs as little as possible while providing enough volume for all your gear.

How does the Osprey Mutant 38 Backpack manage this?


Ultimately, the Mutant is a bit heavier than other packs of a similar volume but not by much.

The reason it weighs a bit more is because of its increased durability and all the amazing added features we have just run through above.

Other packs that are lower in weight don’t quite compare when it comes to features, comfort, and durability, and therefore the Mutant is still a winner in this section in my eyes.


The Osprey Mutant 38 Backpack is a 38-liter backpack that is a volume usually used for day or overnight mountaineering trips.

But, thanks to its intelligent design and all the extra gear attachments, this is actually a pack you can use for 4-5 day adventures which you would usually use a 58-liter pack for.

Overall, the Mutant 38 does amazingly well when it comes to volume vs carrying caapcity.

Value For Money

Osprey Mutant 38L Climbing and Mountaineering Unisex Backpack, Tungsten Grey, S/M

The Mutant costs $194.95 which is a standard cost for a mountaineering backpack around the 38-liter mark. But, the Osprey Mutant 38 is by no means your average mountaineering pack.

With all its comfort, awesome features, durability, and the fact you can fit enough for a longer adventure inside it, we think it is excellent value for money.


Scoring 82 out of 100 on our rating system,  the Osprey Mutant 38 has done very well.

It excels when it comes to durability, materials, volume, comfort, features, and value for money but lost some points in the weight and features categories as it could be lighter and a few tweaks to the features would make it better.


Overall, the Osprey Mutant 38 Backpack is simply fantastic. Between the levels of comfort it provides with the awesome features that make mountaineering easier plus the amazing amount of things it can hold, it has to beat.

Add in the handy removable frame, lid, and foam, plus the awesome carry system, this is the 38-liter pack all alpinists should own.