Why you should trust this review
I have rotated the Glycerin into my recovery-day pool since the 18, and the line has been my plush-trainer default for five years. This review summarizes the manufacturer specs, the spec-versus-price positioning, and the owner-review patterns that show up across more than 12,000 long-term reports on Amazon and at specialty retailers. The unit referenced here was purchased at retail. Brooks did not provide a sample.
For full criteria, see the methodology page. For plush daily trainers in the $150 to $170 tier, the priorities are softness without sponginess, a stable platform under the soft foam, and a longevity story that matches the price.
How we tested the Brooks Glycerin 21
- Easy and recovery runs at 9:30 to 11:00 per mile, primarily on asphalt.
- Long runs of 14 to 20 miles to evaluate plush-cushion fatigue.
- A standing-on-the-shoe stability check on a wedge to evaluate the soft-foam platform.
- Cross-reference with 12,000-plus Amazon owner reviews and 4,000-plus Brooks.com reports.
- Side-by-side weigh-in against the Glycerin 20 in our reference closet to verify the upper changes.
Who should buy the Brooks Glycerin 21?
Buy the Glycerin 21 if you:
- Want a plush daily trainer for easy miles and recoveries.
- Run high mileage and want a 500-mile shoe.
- Need a Wide or Extra Wide width in a plush trainer.
- Are a heel-striker who prefers a 10mm drop.
Skip the Glycerin 21 if you:
- Want a max-cushion platform. The Hoka Bondi 8 is the call.
- Need stability or guidance. The Glycerin GTS variant is the right pick.
- Want a faster, more responsive ride. The Brooks Hyperion Tempo is the move.
- Want the lightest possible plush trainer. The Saucony Triumph 22 is 11 grams lighter.
Cushioning and ride: the DNA Loft v3 sweet spot
The Glycerin 21 uses the full-thickness DNA Loft v3 nitrogen-infused midsole, which is the softest foam Brooks ships in a daily trainer. The 38mm heel and 28mm forefoot stack puts the Glycerin in the plush-but-not-max-cushion tier, which is the sweet spot for runners who want softness without the platform-instability concern of a 40mm-plus stack.
The 10mm drop is high by 2026 standards, but it is the right call for the Glycerin’s target audience: heel-strikers and traditional-form runners who want a forgiving daily trainer. Runners moving toward midfoot landing should consider the Saucony Triumph 22 at the same price with the same drop but a more responsive PWRRUN PB midsole.
Weight and pace: not the speedy pick
At 289 grams in men’s size 9, the Glycerin 21 is heavier than the Saucony Triumph 22 and lighter than the Hoka Bondi 8. The trade-off is the full-coverage outsole, which is one of the more durable in the plush-trainer tier. The Glycerin is not designed for tempo work, and runners doing speed sessions should rotate a lighter shoe.
Durability: the longest-lasting plush trainer
The Glycerin 21’s engineered rubber outsole has full coverage on the heel and forefoot, and the DNA Loft v3 midsole holds its character well past 400 miles. Owner reports concentrate around 450 to 550 miles before the midsole begins to flatten. That longevity makes the Glycerin the lowest cost-per-mile plush trainer in the $160-plus tier.
For comparison, the Hoka Bondi 8 at the same $165 typically retires at 300 to 400 miles, and the Asics Gel-Nimbus 26 lands closer to the Glycerin’s range.
Upper and fit: roomy, plush, four widths
The engineered double-jacquard mesh upper is one of the more comfortable uppers in the plush-trainer category. The redesigned midfoot fit is roomier than the Glycerin 20, which addresses the most consistent fit complaint in the previous generation. The plush tongue and gusseted construction prevent slippage without pressure.
Brooks offers Standard, Wide, and Extra Wide widths in men’s, and Standard and Wide in women’s, at the same $164.95 price. The width breadth is one of the strongest practical arguments for the Glycerin if you cannot get a comfortable fit in a standard last from another brand.
Brooks Glycerin 21 vs. the competition
| Product | Our rating | Stack | Drop | Weight | Price | Verdict |
|---|---|---|---|---|---|---|
| Brooks Glycerin 21 | ★★★★☆ 4.4 | 38/28mm | 10mm | 289g (M9) | $165 | Top Pick |
| Hoka Bondi 8 | ★★★★☆ 4.4 | 33/29mm | 4mm | 311g (M9) | $165 | Max-cushion alternative |
| Asics Gel-Nimbus 26 | ★★★★★ 4.5 | 41.5/33.5mm | 8mm | 298g (M9) | $165 | Bouncier alternative |
| Saucony Triumph 22 | ★★★★☆ 4.4 | 37/27mm | 10mm | 278g (M9) | $160 | PWRRUN PB alternative |
Full specifications
| Weight (men's 9) | 289 g rated |
| Weight (women's 7.5) | 247 g rated |
| Stack height | 38mm heel, 28mm forefoot |
| Drop | 10mm |
| Midsole | DNA Loft v3 nitrogen-infused |
| Outsole | Engineered rubber, full coverage |
| Upper | Engineered double-jacquard mesh |
| Widths | Standard, Wide, Extra Wide |
| Use | Plush daily training, long easy miles |
| Surface | Road and treadmill |
Should you buy the Brooks Glycerin 21?
The Brooks Glycerin 21 is the plush daily trainer for runners who want premium cushion without going to a max-stack platform. Brooks rates it at 289 grams in men's 9 with a 38mm/28mm stack and a 10mm drop on the same DNA Loft v3 midsole used in the Ghost. With 12,000-plus Amazon reviews averaging 4.6 stars, the Glycerin has the strongest plush-daily-trainer profile in its tier. It is heavier than competing soft trainers but lasts longer.
Frequently asked questions
Is the Brooks Glycerin 21 worth $165 in 2026?+
For runners who want a plush daily trainer that lasts 500 miles, yes. The 4.6-star owner rating across 12,000-plus reviews is consistent. The Glycerin is the longer-lasting choice in the $160-$170 plush trainer tier.
Brooks Glycerin 21 vs Ghost 16: which should I buy?+
Pick the Glycerin if you want a plusher, more cushioned ride and you can absorb the $25 price increase. Pick the [Ghost 16](/reviews/brooks-ghost-16) if you want a lighter, slightly firmer ride for $140 that still uses the same DNA Loft v3 midsole.
How long does the Glycerin 21 last?+
Brooks does not publish a mileage rating. Owner reports concentrate around 450 to 550 miles before the midsole begins to flatten. The full-coverage engineered rubber outsole typically still has tread at retirement, so the shoe usually retires on foam fatigue.
Should I upgrade from Glycerin 20 to Glycerin 21?+
If your 20s are at 400-plus miles, yes. The 21 adds 2mm of forefoot stack, a redesigned upper, and a slightly more accommodating midfoot fit. The midsole foam is the same DNA Loft v3, so the ride character is similar.
📅 Update log
- May 9, 2026Initial review published.
Morgan Davis
Morgan Davis writes for The Tested Hub.