Womens Gamma MX Hoody-Sweatshirts & Hoodies-Arc'teryx-Carob-Mountain Sports
Arc'teryx

Women's Gamma MX Hoody

Weather-resistant softshell for getting after it in mixed conditions. This product was previously the Gamma Heavyweight Hoody.

$400
Color: Mongoose
Also inWomen's
Size:
Size guide
  • Free shipping on orders $150+
  • Free pickup at our Arlington, TX store today
  • Free 30-day returns
Top features
Hardwearing Fortius™ 2.0 softshell fabric
Taped seams
FC0 DWR (Durable Water Repellent) finish repels moisture…
Description

For the days where you need a little extra warmth but not a fully insulated layer, and a little extra weather protection but not a fully waterproof jacket — the Gamma MX Hoody has you covered. More breathable than a hardshell, this softshell offers excellent warmth for little weight and just-enough weather resistance for mixed conditions and colder days. Wear it as a standalone on chilly hikes and approaches, or as a midlayer on cold, wet-weather treks.

Perfect for
Trail
Hiking and mountain days.
Wind and weather
Repels the shoulder seasons.
Built to last
Covered by the Arc'teryx warranty.
Features
  • Hardwearing Fortius™ 2.0 softshell fabric. Hardwearing Fortius™ 2.0 softshell fabric has increased warmth to weight ratio and durability, with wind resistance and a DWR finish
  • Taped seams. Taped seams for weather resistance, a low-profile finish, and added strength
  • FC0 DWR (Durable Water Repellent) finish repels moisture…. FC0 DWR (Durable Water Repellent) finish repels moisture and is free from intentionally added PFAS
  • Adjustable hem draw cord seals out drafts.
  • Helmet compatible StormHood™ provides full coverage…. Helmet compatible StormHood™ provides full coverage without impacting visibility
  • Articulated patterning. Articulated patterning for unrestricted mobility
Size & Fit
Slim
Regular
Relaxed

Standard fit with room to move. True to size for most.

  • Our classic fit is cut comfortably throughout the chest, waist, hip, and thigh. It allows freedom of movement, provides shape, and layers comfortably over or under our layers.
  • Garment Centre Back Length: Size S is 26"/66cm - Varies by size
Open size guide
Materials
  • Body: Fortius™ 2.0 - 60D Synthetic Stretch Softshell with poly fleece backer, 233gsm, FC0 DWR - 84% Nylon, 16% Elastane 100% Polyester Backing.
  • Lining: Recycled Polyester Brushed Pocket Mesh, 158gsm - 100% Recycled Polyester.
  • Care: Machine wash gentle low; Tumble dry permanent press low; Do not bleach; Wash dark colours separately; Do not dry clean; Iron low; Do not use fabric softener; Double rinse.
About the brand

Born in the Coast Mountains of British Columbia, Arc’teryx designs gear built for the wildest weather and the steepest lines. Every jacket, pack, and layer is engineered for precision and performance — because when conditions get real, your gear should too. At Mountain Sports, we love Arc’teryx for its unmatched craftsmanship and commitment to doing more with less, in nature’s harshest playgrounds.

Shop all Arc'teryx

SKU X000009456 · Style X000009456
Size guide

Arc'teryx Size Chart - Women's Apparel

Arc'teryx Sizing Chart

Measurements are in inches, unless otherwise noted. Charts reflect body measurements, not garment measurements.

Women's Jackets & Shirts:

Size Sleeve Chest Waist Hip
XXS 28.5 30 23.5 33
XS 29.5 32 25.5 35
S 30.5 34 27.5 37
M 31.5 36 29.5 39
L 32 39 32.5 42
XL 32.5 43 36.5 46
XXL 33.5 47 40.5 50

Arc'teryx sizes are intended to fit the body measurements above. If your measurements are between sizes, select a larger size for a looser fit or a smaller size for a tighter fit.

Women's Pants & Shorts (Alpha Sizes):

Size Waist Hip Regular Inseam Short Inseam Tall Inseam
XXS 23.5 33 30.5 28.5 33.5
XS 25.5 35 30.5 28.5 33.5
S 27.5 37 31 29 34
M 29.5 39 31.5 29.5 34.5
L 32.5 42 31.5 29.5 34.5
XL 36.5 46 32 30 35
XXL 40.5 50 32 30 35

Women's Pants (Numeric Sizes 00 - 16):

Size Waist Hip Regular Inseam Short Inseam Tall Inseam
00 24 33.5 30.5 28.5 33.5
0 25 34.5 30.5 28.5 33.5
2 26.5 36 31 29 34
4 27.5 37 31 29 34
6 28.5 38 31 29 34
8 30 39.5 31.5 29.5 34.5
10 31 40.5 31.5 29.5 34.5
12 33 42.5 32 30 35
14 35 44.5 32.5 30.5 35.5
16 37 46.5 32.5 30.5 35.5

Numeric pant sizes correspond to the body measurements shown above. Several Arc'teryx pant models are sized numerically and may be offered in Short, Regular, and Tall inseam lengths - see each product page for the options available.

How to measure: Sleeve - with your arm relaxed at your side and slightly bent, measure from the center back of your neck, across the shoulder, over the elbow and down to the wrist. Bust - with arms relaxed at your sides, measure under your arms around the fullest part of your bust. Waist - measure around your waist at the narrowest part. Hip - standing with feet hip width apart, measure around your hips at the widest part. Inseam - from a standing position, measure from your crotch down the inside of your leg to the floor.
Performance

How it ranks across conditions.

Calibrated against comparable products we stock, so you can compare like for like.

Warmth

Light
Moderate
Warm
Warmest

Fleece-backed softshell.

Weather protection

Water resistant
Water repellent
Highly weatherproof
Waterproof

PFAS-free FC0 DWR finish sheds light rain.

Breathability

Low
Moderate
High
Very high

Woven face fabric with no membrane.

Packability

Bulky
Moderate
Packable
Ultralight

Brand-stated weight 510g.

Best for

Is this right for you?

Hiking and trail days

Moves well on the up, layers under a shell when the weather turns.

Not for: Sustained heavy rain — this repels, it does not seal.

Shoulder season

The range where a shell is too much and a tee is not enough.

Not for: Deep winter without something warmer underneath.

Everyday wear

Clean enough for town; the fabric stands up to a pack and a car seat.

Not for: Formal occasions.

Full spec sheet

Technical Specs

Style numberX000009456
Weight510g / 1 lb 2 oz
FitRegular
Centre Back LengthSize S is 26"/66cm - Varies by size
LiningRecycled Polyester Brushed Pocket Mesh, 158gsm - 100% Recycled Polyester
BodyFortius™ 2.0 - 60D Synthetic Stretch Softshell with poly fleece backer, 233gsm, FC0 DWR - 84% Nylon, 16% Elastane 100% Polyester Backing
Country of manufactureVietnam
VendorArc'teryx
Questions, answered

Before you buy.

Pulled from chats, emails and store visits. The things people actually ask us before they buy. Don't see yours?

Ask a question
How do I wash it?

Arc'teryx specify: Machine wash gentle low; Tumble dry permanent press low; Do not bleach; Wash dark colours separately; Do not dry clean; Iron low.

Where is it made?

This style is manufactured in Vietnam. Arc'teryx publish the facility as SPECTRE GARMENT TECHNOLOGIES VIETNA, Vietnam.

How does it fit?

Arc'teryx call this a regular fit. Our classic fit is cut comfortably throughout the chest, waist, hip, and thigh. It allows freedom of movement, provides shape, and layers comfortably over or under our layers.

Will it keep the rain off?

It sheds light rain and blocks wind, which covers most shoulder-season days. It is not a waterproof shell — in sustained rain you want a hardshell over the top.

What does the Arc'teryx warranty cover?

Arc'teryx warrant their garments against defects in materials and workmanship for the practical lifetime of the product. That covers manufacturing faults, not wear and tear or accidental damage. Bring it to us and we will help you start the claim.

Find the right one for you

How the Gamma MX Hoody compares

Head-to-head against the closest alternatives we stock, so you can see where this one sits before you commit.

Feature
Arc'teryx
Gamma MX Hoody
You're viewing
Arc'teryx
Gamma Lightweight Hoody
Weight510g / 1 lb 2 oz260g / 9.2 oz
InsulationFleece-backed softshellUninsulated softshell
Main fabricFortius™ 2.0 double weave, 233gsm, FC0 DWRFortius™ DW 1.0 double weave, 125gsm
Weather protectionWind resistant, water repellentWind resistant, water resistant
FitRegularFitted
MSRP$400$260
Pick your sizeShop →

Browse all softshell jackets →

Real people, always

Our story

Someone who's been there

Ask about a trail, a tent or a fit, and a person who uses the gear writes back.

Picked, not just stocked

We carry the brands we trust on our own weekends outside.

Easy if it's not right

Free 30-day returns, and help finding the one that is.

Free shipping over $150

Shipped nationwide since '96. Some exclusions apply.