Type a shoe name, like Pegasus, Clifton or Kayano.

Brooks Glycerin 21

Daily trainer · Neutral · Road · 10 oz · 10mm drop · 38/28mm stack

Discontinued — we no longer see this shoe in stock. The Brooks Glycerin 22 replaced it

How it ranks

The Brooks Glycerin 21 is one of the strongest daily trainers in our data. Comfort and cushioning are its strongest sub-ratings. Looks scores well below its other sub-ratings. The rating rests on 19 runner reviews and 12 other rated shoes in the Glycerin product line.

Brooks Glycerin 21

of 5

Excellent

97/100
Overall
97
Comfort
99
Durability
98
Cushioning
98
Value
81
Appearance
81
Confidence

Confidence

How settled the rating is against every other rated shoe. A shoe can rate high on confidence with relatively few reviews of its own when its product line has a long record and external ratings from retailer sites agree. Confidence will score low when we have few ratings or when runners disagree.

See the product line's history

Confidence

92/100

92

What runners say

“These shoes are so comfortable, I could sleep in them.”
4/5 Full review 15 mpw training for a marathon came from the Mizuno Wave Rider 27
“Cushioning is good and firm.”
5/5 Full review 40 mpw training for 5K and 10K came from the New Balance Fresh Foam X 860 v13
“These are a bit soft in that department so I had to purchase a new pair of shoes before the usual amount of miles.”
4/5 Full review 15 mpw training for a marathon came from the Mizuno Wave Rider 27
“The Brooks Glycerin 21 meets all those needs.”
5/5 Full review 55 mpw training for a marathon came from the Mizuno Wave Rider 28
“Heel striking not cushioning as advertised.”
2/5 Full review 6 mpw came from the Brooks Ghost 16

Prefer this shoe over another

57% 4/7

Where to buy

No offers available

Affiliate links included. They never affect our ratings.

Prices updated daily. Last checked Sep 14.


Pros

  • Reviewers praise the comfort, and one calls the cushioning good and firm.
  • Durability averages 4.5 out of 5, and one reviewer logs 40 miles a week for ten weeks without trouble.
  • One reviewer at 72 and another who describes themselves as heavy both say it lets them get their mileage in.

Cons

  • Appearance and value are the weakest dimensions, at 4.2 out of 5 each.
  • One heavier reviewer wears the sole out before the usual mileage, and another says it does not cushion a heel strike as advertised.

Rating & Confidence vs. other shoes for sale

Each dot is one rated shoe for sale, placed by its rating and by how much evidence sits behind it. Shoes toward the top right are both well rated and well established.

Confidence
50 60 70 80 90 100 25 50 75 100

Better Shoes Rating

Glycerin 21 rates 97. This shoe has high certainty. See how we rate shoes.

Better Shoes Rating of prior versions of the Brooks Glycerin

Each dot is one version of the Glycerin, placed by its rating and release year. The gold dot is this shoe.

Rating

Release year

We use the reviews of past versions to inform this shoe’s rating. See why.
  • Glycerin 23

    2026 · 4 reviews

    93 Excellent

    79 Confidence

  • Glycerin 22

    2025 · 4 reviews

    94 Excellent

    84 Confidence

  • Glycerin 21 This shoe

    2023 · 19 reviews

    97 Excellent

    92 Confidence

  • Glycerin 20

    2022 · 50 reviews

    97 Exceptional

    97 Confidence

  • Glycerin 19

    2021 · 4 reviews

    96 Excellent

    85 Confidence

  • Glycerin 18

    2020 · 2 reviews

    79 Decent

    49 Confidence

  • Glycerin 17

    2019 · 21 reviews

    98 Exceptional

    96 Confidence

  • Glycerin 16

    2018 · 21 reviews

    96 Excellent

    94 Confidence

  • Glycerin 15

    2017 · 17 reviews

    89 Good

    91 Confidence

  • Glycerin 14

    2017 · 3 reviews

    95 Excellent

    85 Confidence

  • Glycerin 13

    2016 · 3 reviews

    96 Excellent

    82 Confidence

  • Glycerin 12

    2014 · 27 reviews

    93 Very good

    93 Confidence

  • Glycerin 11

    2014 · 16 reviews

    87 Good

    86 Confidence

Reader Ratings

19 ratings
5/5 13
4/5 5
3/5 0
2/5 1
1/5 0

Specs & fit

Sizing and ride details at a glance.

Weight
10 oz
Release
2023 Q4
Stack Height
38mm heel - 28mm toe
Drop Height
10mm

Runner reviews

Write a review

Showing 6–8 of 8 written reviews

Great Shoe for Daily Runs

5/5

Overall

Great comfortable shoe to run in.

Anonymous runner · Jun 28, 2024

15 mpw training for 5K and 10K came from the Brooks Ghost 16

Comfort
5/5
Cushioning
5/5
Durability
5/5
Appearance
5/5
Value
5/5

Reader review

2/5

Overall

Heel striking not cushioning as advertised 

Anonymous runner · Jun 14, 2024

6 mpw came from the Brooks Ghost 16

Comfort
2/5
Cushioning
2/5
Durability
3/5
Appearance
3/5
Value
2/5

Don't want to take them off, but soft soles for a hefty gal.

4/5

Overall

These shoes are so comfortable, I could sleep in them.  After trying a myriad of other brands, thee were a welcome cushion.  I am a heavy person so I wear out a shoe's bottom sole first.  These are a bit soft in that department so i had to purchase a new pair of shoes before the usual amount of miles.  They give me no other issues (no blisters, chafing, etc.) so I don't mind.

Adrienne · Dec 4, 2023

15 mpw training for a marathon came from the Mizuno Wave Rider 27

Comfort
5/5
Cushioning
5/5
Durability
4/5
Appearance
3/5
Value
4/5

Alternatives

Other shoes worth considering.

More from Brooks

Compared to other shoes

See how this shoe compares to others like it.

Current shoe
Choose a model
Best durability
Newest / Lowest price
Lightest / Best overall / Best comfort
Shoe properties
Type
Daily trainer
Daily trainer
Daily trainer
Pronation
Neutral
Neutral
Neutral
Weight
10 oz M
8.5 oz M Lightest
Stack
38/28mm
40/35mm
Drop
1mm
5mm
Release
2023 Q4
2026 Newest
2023 Q1
MSRP
$175
$145
Best price
$145 Lowest price
$149.99
Ratings
Overall
Excellent (97)
Excellent (93)
Exceptional (99) Best overall
Comfort
Exceptional (99)
Exceptional (99)
Exceptional (99) Best comfort
Cushioning
Exceptional (98)
Exceptional (98)
Exceptional (99) Best cushioning
Durability
Exceptional (98) Best durability
Exceptional (98)
Very good (92)
Appearance
Good (81)
Decent (79)
Very good (91) Best appearance
Value
Good (81)
Decent (76)
Good (88) Best value
Specific shoe

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