I recently picked up the Brooks Glycerin 21 after my go-to shoe, the Brooks Adrenaline, was out of stock. I was told the Glycerin was a good alternative, but unfortunately, it didn’t live up to that promise—at least not for me. Right out of the box, the Glycerin 21 felt plush and well-cushioned, which initially gave me hope. However, once I started running, the comfort quickly disappeared. The fit felt off, especially around the arch and heel, and I noticed discomfort within the first couple of miles. After a few runs, the pain in my feet became consistent enough that I had to stop using them altogether. To be fair, the Glycerin 21 might work well for runners who prefer a softer, more neutral shoe, but if you're coming from the Adrenaline—especially if you rely on the stability features—it’s just not the same experience. I felt like I had less support, which may have contributed to the discomfort during runs. Overall, I wouldn't recommend the Glycerin 21 as a substitute for the Adrenaline, especially if foot support and comfort are high priorities for you. Hopefully, the Adrenaline comes back in stock soon because this one just didn’t work for me.

Good After Break In.

I love the cushion of these shoes. I’m currently using them for my longer runs. Initially I had a bit of discomfort on the outside of one foot but after some time they seem to have broken in and that discomfort is all but gone. I’m a big guy that doesn’t run fast so they don’t feel very heavy. I would have given these 5 stars had it not given me discomfort in one of my feet.

Good Cushioning Sneaker

Purchased these sneakers in black 3 weeks ago. These are very cushioned and fit a little smaller than other Brooks styles.

Maybe The Best Shoe I’ve Had

Love the comfort. Definitely much softer than the 21,fit is great in forefoot and heel. Felt good for the first 5 mile run. Nothing short of amazing!

Great!

We purchased these for our Disney trip. As much as we loved them previously, they hurt my husband's heels? Not sure if they needed some breaking in prior or if it's this model but they did great for our joints.