Which pillow to choose: what science really says

In short: studies show that a pillow mainly affects stiffness upon waking, very little the quality of sleep itself, and that no material clearly comes out on top. The criterion that really matters is height - the one that keeps your neck aligned with your spine in your position. And the silk pillowcase is playing a different game altogether.

We have written a great deal here about what covers the pillow. The momme, the grade, the way silk glides beneath the cheek. Almost never about what lies underneath. This is a blind spot, and it is a troubling one: in October, when the nights grow longer and we spend an extra hour under the covers, it is the pillow - not the pillowcase - that determines how we turn our head in the morning.

What science says (and what it does not say)

The literature on pillows is more modest than one might imagine, and that is interesting in itself.

The most robust synthesis remains that of Chun-Yiu, Man-Ha and Chak-Lun, published in Clinical Biomechanics in 2021: a systematic review with a meta-analysis covering 35 articles, including nine studies of good methodological quality and 555 participants. Its results are nuanced. Latex and spring pillows significantly reduced neck pain and symptoms upon waking, with noticeably higher satisfaction. But the same study found no effect of pillow design on sleep quality, and observed that cervical spine alignment in the side-lying position did not appear to vary according to the material.

A more recent systematic review, Ghosh, Goyal and Goyal, Rehabilitación, 2025 (vol. 59, no. 3, 100922), reaches the same conclusion while being even more stringent: of the 29,091 references screened, only five studies (239 participants) were usable. Improvements in pain were minor and not statistically significant, sleep quality scores remained unchanged, and no type of pillow - latex, foam or standard - proved clearly superior. The authors conclude that the evidence is limited and highly heterogeneous, and call for better trials.

What we can honestly take away from this, without overinterpreting it: a suitable pillow seems to modestly improve comfort upon waking and satisfaction. It does not help you sleep better in any measurable sense, and there is no miracle material. If you wake up with persistent neck pain, the pillow is one piece of the picture - not a treatment, and the matter deserves the advice of a healthcare professional.

The only criterion that really matters: your sleeping position

Since the material does not make the difference, geometry is what decides. A good pillow is one that exactly fills the gap between your head and the mattress, so that your neck remains aligned with your spine. This gap is not the same size depending on how you sleep.

A simple test, standing against a wall: slide the pillow behind your neck in the position in which you sleep. If you have to force your head back to touch the wall, it is too high. If your head tilts backward, it is too low. It is rudimentary, but more reliable than any label.

Filling, firmness, lifespan

• Latex. The most favorably documented in the 2021 meta-analysis. Springy support that pushes back slightly: you sink into it less.
• Memory foam. Stable support that contours to the neck and does not compress during the night. It retains heat - worth noting if you sleep hot.
• Down and feathers. Incomparable softness, but the height collapses under the weight of the head; it needs fluffing every morning.
• Microfiber. Affordable and pleasant at first, but it quickly compresses. This is often the pillow people keep for too long.
• Silk. Lightweight, breathable softness, appreciated by sleepers sensitive to dust; this is a filling comfort feature, not a health device.

As for lifespan: a pillow that does not regain its shape when folded in half and released has reached the end of its life. In practice, two to three years for most fillings, longer for good latex.

And what about a silk pillowcase?

This is where the two subjects clearly diverge, and that is why I wanted to write this article.

The pillow is the skeleton: it supports the neck. The pillowcase is the interface: it determines what your skin and hair endure during seven hours of friction. The two are not interchangeable. A mulberry silk pillowcase will never make up for a sagging pillow - and a perfect pillow left bare, or covered in rough cotton, leaves your cheek creased when you wake up and your hair static in the morning. We have explained elsewhere what science says about pillow marks, and how to choose your pillowcase.

For a pillowcase, the right benchmark remains the fabric weight: 19 to 22 momme for everyday use, neither too thin nor too heavy. If that number means nothing to you, everything is explained in our momme guide.

One practical detail that is often overlooked: check the size before buying. In France, the square 65 × 65 cm and rectangular 50 × 70 cm sizes coexist, and a silk pillowcase will gape or pull if it does not match the pillow it covers.

Where to start, concretely

• You sleep on your side, or wake up with a stiff neck - an ergonomic memory foam cervical pillow, for consistent height and support.
• You're looking for softness and breathability - a mulberry silk-filled pillow, lighter beneath your head.
• You often sleep somewhere other than home - a silk neck pillow that solves the problem of train and plane travel.

The rest of the selection can be found in the Pillows collection. And if you change your pillow this week, take the opportunity to look at the pillowcase you are putting back on it: it is often the oldest piece on the bed.

Frequently asked questions

“Silk pillow” - does that mean the pillow or the pillowcase?

Both expressions are used, and this is a frequent source of confusion. A silk pillow refers to a pillow filled with silk. A silk pillowcase, on the other hand, is the cover that goes over it. You can have one without the other - and it is the pillowcase that touches the skin.

Do you need a firm pillow if you have neck pain?

Not necessarily. The available research does not identify one winning firmness: it is the height suited to your sleeping position that most often comes up in the conclusions. A very firm pillow that is too high is still a poor pillow. For persistent pain, speak to a healthcare professional.

How often should you replace your pillow?

The real test is mechanical: fold it in half and let go. If it stays folded, it no longer provides any support. Allow two to three years for most fillings.

Is a cervical pillow compatible with a silk pillowcase?

Yes, provided you choose a pillowcase in the right size: ergonomic pillows often have their own format, narrower than a classic 65 × 65. Measure before ordering.

What if I sleep on my stomach?

This is the most demanding position for the neck, as it requires rotation. The flattest pillow possible is the best compromise; some sleepers do without one entirely and instead slip a thin pillow under their pelvis.

A bed, when you get down to it, is a stack of decisions layered on top of one another: the mattress, the pillow, the pillowcase. We often focus on the most visible one. The pillow is the quietest, and yet it is the one we feel with the first movement of the morning.

Discover StudioSoie pillows →

— Inès, for the StudioSoie Journal