Is the TikTok-famous Pillow Cube the secret to a better night's sleep? After trying it, I'm not so sure.

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If you've seen ads with someone sleeping on what looks like a quilted tissue box, then you're acquainted with the Pillow Cube. The foam pillow, designed for side sleepers, is meant to keep your head parallel to the mattress so your neck doesn't curve at an awkward or uncomfortable angle. 

For the most part, I sleep on my side and frequently have trouble falling asleep right away. I wanted to see if the Pillow Cube Side Cube could really really be one of the best pillows, helping me fall asleep more quickly. 

What is the Pillow Cube?

The Pillow Cube is a squarish foam pillow that's intrigued and befuddled TikTok. The shape doesn't have much to do with the pillow's ability to keep your head and neck aligned but rather the foam core does. It's soft but structured, without too much give so your head doesn't sink in too much.

"That's not a cube," my astute husband said when he saw the pillow. He's right. The Side Cube is rectangular, giving you more room to flip over or roll than an actual cube-shaped pillow.

The Side Sleeper Pro is 24 by 12 inches and available in three heights: 4, 5, and 6 inches. The pillow is 100% polyurethane, and the cover is an spandex and polyester blend. 

How to find the right size Pillow Cube

Essentially, you want to figure out how much space there is between your head and mattress when you're lying down. You want your neck aligned with your head, not curving up or down. A video from the company suggests putting your head on a stack of books and adding and subtracting books until you find the right height. You then measure the stack to find your pillow cube height. Mattress firmness also factors into the equation. 

Alternatively, you can choose your pillow based on your height. When I emailed the company about testing a sample, they simply asked for my height and mattress firmness. (For what it's worth, I got the same result when I took Pillow Cube's height quiz.)

What's it like to sleep with the Pillow Cube?

Sleeping on the Pillow Cube was a bit of an adjustment. I often sleep with my regular pillows propped against the headboard, but the Pillow Cube lies flat on your bed. When I press down on it, the Cube's foam resumes its usual shape more slowly than a feather pillow. When I lay down, my head sank in but not far enough to make my neck curve. 

I am mostly a side sleeper but do occasionally fall asleep on my back if I'm listening to an audiobook before bed. For me, the Pillow Cube worked fine either way, but I do have the slimmest version. I would imagine the thicker pillows wouldn't work for back sleepers, and they're very much not for stomach sleepers, who need very flat pillows. 

One thing you should keep in mind if you're measuring for a pillow is whether you tend to sleep on your arm or turn your body a bit so you're resting a bit on your chest or back too. I do sometimes round my shoulder in, and I found the pillow a bit less comfortable in those instances.  

Can you use a normal pillowcase with the Pillow Cube?

Technically you can, but the excess material just kind of flops around, looking sad. It's probably not a huge deal for most people, but it's something to be aware of if you make sure your bed looks picture-perfect every morning. 

Also, Pillow Cube's website says the pillowcase and outer cover are machine-washable, but the instructions on the pillowcase's tag said to hand wash. I put it in the washing machine on cold, and it still fits.

Is the Pillow Cube a magic bullet for a better night's sleep?

No. For one thing, there are only a few heights for a wide range of body types. The pillow isn't adjustable like the Coop Home Goods Adjustable Pillow, the top choice in our pillow guide. If you need, say, 4.5 inches, you'll have to add some extra padding to a 4-inch pillow Pillow Cube to make it just right. 

I found that the Pillow Cube traps heat. After lying on the pillow for even a minute without the pillowcase, the Pillow Cube felt noticeably warmer. The brand does sell a cooling version of the Side Cube, the Ice Cube. (Check out our guide to the best cooling pillows if you tend to sleep hot.)

As for the Pillow Cube's promises to make me fall asleep faster and stay asleep longer, these didn't bear out according to my Apple Watch sleep stats. I still averaged around 7.5 hours. 

If you find you need a different height or just don't like the feel of the foam, you can return or exchange the Pillow Cube within 60 days of purchase. You can also choose to add a 2-year warranty for $21.99. That flexibility is especially important in a pillow that isn't for everyone.

What are your alternatives?

We still think the best pillow for side sleepers is the Coop Sleep Goods Original Pillow, which has an adjustable fill so you can dial in the perfect fit. Individual anatomy varies, so it's hard to find a one-size-fits-all pillow for side sleepers, but the Coop comes close since you can add or remove filling to find your ideal loft.

If you suffer from neck and back pain, we recommend the Eli & Elm Cotton Side Sleeper Pillow in our best pillows for neck pain guide. Its unique C-shape helps cradle your head and neck and promote better spinal alignment.

The bottom line

For me, the Cube was a good balance of support and softness, but I didn't notice an enormous difference from my everyday, fraction-of-the-cost pillows. 

Whether you'll have similar results will depend on whether the Pillow Cube's thickness perfectly fits the gap between your head and mattress. If you want to test the viral sensation yourself, the Pillow Cube does offer a 60-day return so you can try it out.