Brooks Glycerin 21 Release Date and Exclusive Preview Insights!


The highly anticipated Brooks Glycerin 21 is set to make its debut on the 1st of February 2024. Building on the success of its predecessors, this upcoming release promises to deliver advanced features, comfort innovations, and cutting-edge design to enhance the running experience.

With its scheduled launch just around the corner, runners can anticipate a new chapter in cushioned performance and tailored support with the Brooks Glycerin 21.


Brooks Glycerin Release Date & Preview

Stay in the know by frequently consulting our running shoe release date calendar for the latest updates on upcoming launches.


I’m Eric Barber, and I’m thrilled to share my insights today on the highly anticipated release from Brooks, none other than the Glycerin 21.

Before delving into the details, it’s important to note that Road Runner Sports graciously provided me with the Brooks Glycerin 21. It’s crucial to mention that they had no preview of this article and all the thoughts and opinions expressed here are entirely my own.

If you’re not familiar with Brooks running shoes, the Glycerin series is distinguished by its substantial cushioning, making it an ideal choice for runners looking for a plush underfoot experience during longer runs or for individuals who spend prolonged hours on their feet.


Versions of the Glycerin 21

The Glycerin 21 offers a diverse range with four versions to cater to different preferences: the regular Glycerin, Glycerin GTS, Glycerin Stealthfit, and Glycerin Stealthfit GTS.

The Stealthfit versions have a knit upper for a snug fit, while maintaining the original Glycerin 21’s midsole, featuring a more traditional engineered mesh upper.

The GTS, short for Go-to Support, is applied to the stability editions, introducing GuideRails on the medial and lateral sides to ensure proper alignment during your run.

The midsole design remains consistent with added foam walls toward the back for additional support. Price-wise, the Glycerin is priced at $160, slightly edging out the Ghost, which comes in at a more budget-friendly $140.


Stack Height

In comparing Brooks Ghost, a quintessential traditional neutral daily trainer with a moderate cushioning level, to the Glycerin 21, it’s clear that the Glycerin 21 takes the lead with its maximal cushioning design.

The Glycerin 21 undergoes a significant enhancement, now boasting an additional two millimeters in stack height, bringing it to 28mm in the heel and 18mm in the forefoot, all while maintaining the familiar 10mm drop. I’m quite happy to see the Glycerin go up in stack height and also down in weight ever so slightly.

I think it’s a move in the right direction. Upon my initial trial, I found myself pleasantly surprised, particularly by the impressive updates to the midsole.


The Brooks Glycerin is one of these top-notch max cushion running shoes. Give it a read!



The midsole on the Glycerin 21 is still being branded as DNA Loft V3. However, and this is a big however, it feels completely different compared to last year, which I thought was on the firmer side of things.

It has been softened up a whole lot in a meaningful way and in my opinion, feels quite pleasant. It was a fun surprise to put this on my foot for the first time.


If you’re not familiar, DNA Loft V3 is a nitrogen-infused foam with a distinct manufacturing approach compared to DNA Loft V2 found in the regular Ghost 15 and original Ghost Max.

So, if you like the Ghost and you want to go with more stack height, you can go in two different ways. You can go to the Glycerin with the nitrogen-infused DNA Loft v3 or you can go to the Ghost Max with its DNA Loft V2.

But in 2024, Brooks is going to use DNA Loft v3 in the Ghost 16 and the Ghost Max 2.

I really do think Brooks is making a big step in the correct direction with this reformulation of DNA Loft V3 so much so in fact they probably should have rebranded it or maybe put some daylight between this and the Glycerin 20 just because the Glycerin 20 was so much more firm and had a completely different experience to what I’m getting with this new Glycerin 21.

The 21 has a nice little squish, energy return, and enjoyment.

It’s also just a solid workhorse daily trainer. You can pick up the pace in it if you really want and if you need to slow it down, there’s plenty of cushion as well.

I just found the Glycerin 21 to be so much more enjoyable and I really do think Brooks has a winner here in a big way with this updated version of DNA Loft V3.

I also think that the rocker geometry is more aggressive compared to prior versions. We also have an updated heel geometry with a little bit more of a curve or bevel to it. So, if you heel strike or walk, you definitely will notice that as well.




Because this is the Stealthfit version, it just fits a little bit snug and the toe box is a little bit pointed.

I do think the Stealthfit version just looks cooler. I will give it that. It looks absolutely dope. You have these heavy plastic overlays across the midfoot on both the lateral and medial side to give you some extra support.

The breathability wasn’t half bad. It’s not amazing and I’d probably give it an average rating with these large ventilation zones in the toe box and come off to the side as well.


The tongue is very elastic and quite stretchy so it’s fairly easy to get your foot in and out of the shoe.

The lacing system fairly similar to what we saw last year. You have strands of rope on both sides and the lace is kind of crisscross so they don’t have to go through the upper and then touch your foot at all. It all stays on the outside of the upper.

I think the lacing system was decent, but my issue is if you really do have to pull those laces tight, you have a moderate amount of lace pressure because that knit tongue is so thin.

Moving to the back of the shoe, we still have that knit collar. It’s not my personal favorite but doesn’t really hurt me or help.


The heel counter is also rather flexible with a moderate amount of cushioning.




As far as the lockdown goes, I thought it fit true to size on the more snug side of things. The lockdown was okay typically with these Brooks knit uppers. I do prefer going with the more traditional engineered mesh upper.

The lockdown with the elastic materials and the flexible heel counter wasn’t perfect. It was fine, but I do have a feeling I’ll probably prefer the more traditional engineered mesh upper when that finally comes out.




The big takeaway is it’s an updated compound. Brooks are calling it Road Track. It’s a mix of rubber and recycled silica supposed to help the longevity, but for me it felt kind of like just a classic Brooks outsole.

You do have some moderate flex grooves through the forefoot. They’ve connected one of the flex grooves to try to stiffen things up a bit.

I will say it bends fairly easily although it is more stiff compared to the Brooks Ghost which is very flexible in the forefoot.

So, there’s not too much to write home about with the outsole other than the updated rubber compound to Road Track.



Overall, I was incredibly surprised by the Brooks Glycerin 21. I think it makes some massive and meaningful updates to the Glycerin 20 and I’ll go as far as to say this might be one of Brooks’ best shoes and I’ll pick this all day every day compared to the Ghost.

It’s lighter, it’s more enjoyable, and it has a little bit more energy turn to it and a slightly more aggressive rocker as well.

I’m very excited to also try out the more traditional engineered mesh upper. I think the midsole is a massive winner.

So, let me know down in the comments what you think of Brooks running shoes in general and what you think of this update to the long-running Glycerin series.

About Eric Barber

Eric Barber is a happy father of two little angels, a husband, and a runner. He eats, sleeps, and dreams anything foot related: running shoes, walking shoes, sneakers, you name it. It all started when Eric was a shoe store specialist watching and fitting people's feet day in and day out.

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