Where most pillows go wrong
A fixed-height pillow bends the neck of anyone it wasn't built for. Every Circadian pillow opens, so you set yours.
Why height matters most
A 2021 review of the pillow research since 1997 found no single correct pillow height. A 2025 study found the right height for a side sleeper tracks the width of their shoulders. Different shoulders need different pillows.
Your head is propped above the line, so your neck bends up toward the ceiling for the whole night.
Your head drops toward the mattress, and your neck bends down to meet it. This is what a pillow that goes flat does.
Your head sits in line with your spine, tipped neither up nor down, and it stays there until morning.
Side sleeping opens the biggest gap, so it wants the most height. Back sleeping needs less. Stomach sleeping needs almost none.
Pillow finder
How you sleep most nights
What you want to feel
Organic Cotton Pillow
The densest fiber we fill with, so your head sits on it instead of sinking through. It feels like a pillow is supposed to feel from the first night, and it holds its shape for years.
For side sleeping: keep most of the cotton in, so your ear, shoulder and hip line up.
For back sleeping: take cotton out a handful at a time until your head sits level with your shoulders.
For stomach sleeping: take out most of the cotton, so your head sits close to level with the mattress.
One step softer is the Organic Wool Pillow, soft and springy. One step firmer is the Buckwool Hybrid Pillow, firm buckwheat on one side and soft wool on the other.
Wild-Harvested Kapok Pillow
It feels the closest to down of anything we make. Kapok is the lightest natural fiber on Earth, so it rests softly on your ear instead of pressing into it, and a quick shake each day springs it back full.
For side sleeping: keep it full, so it fills the space between your ear and your shoulder.
For back sleeping: open the zipper a little and ease some kapok out into a bag until your chin sits level.
For stomach sleeping: ease a good share out into a bag, so your head sits close to level with the mattress.
One step firmer is the Tree-Tapped Latex Pillow, a soft, bouncy hug.
Tree-Tapped Latex Pillow
The latex pieces lift your head and spring back every time you turn, so you never sink into a dip. Air moves through them all night, and the latex is tested to OEKO-TEX Standard 100 at Class 1.
For side sleeping: keep it full, so the latex fills the gap to your shoulder.
For back sleeping: scoop out a handful or two over a bag until your chin sits level.
For stomach sleeping: scoop out a good share over a bag, so your head sits close to the mattress.
One step softer is the Wild-Harvested Kapok Pillow, light and cloud-like. One step firmer is the Organic Wool Pillow, soft and springy.
Organic Wool Pillow
Wool gives under your head and springs back, and it stays full with no daily fluffing. It also keeps you one temperature through the night, which hot sleepers notice first.
For side sleeping: keep most of the wool in, so your ear sits over your shoulder.
For back sleeping: lift the top fold of wool away from the outside, opening it at the nearest crease, until your chin sits level. Never tear it.
For stomach sleeping: lift folds of wool away from the outside, opening each at its crease, until your head sits close to level with the mattress. Never tear it.
One step softer is the Tree-Tapped Latex Pillow, a soft, bouncy hug. One step firmer is the Organic Cotton Pillow, dense and familiar.
Buckwheat Pillow
The hulls flex under your head, then lock into the shape you push them into and hold your neck there all night. Air moves between them, so it is also the coolest pillow we make.
For side sleeping: keep it full. The hulls fill the gap to your shoulder and hold it until morning.
For back sleeping: pour out some hulls for a lower pillow that holds the curve of your neck.
For stomach sleeping: pour out a good share of the hulls, so your head sits close to level with the mattress.
One step softer, and the pillow many buckwheat lovers end up choosing, is the Buckwool Hybrid Pillow: firm buckwheat on one side, soft and silent organic wool on the other.
Make it yours
It arrives full, about a third more than most people keep, because it is easier to take some out than to wish you had more.
Open the zipper on the first night and take some out until your head sits level for the way you sleep. Keep what you take out. Sleep on that height for a few nights before you change it again, then give the pillow a few weeks before you judge it.
If you try again, go a little further than feels right. A pillow that is still too tall feels like a normal pillow, while your neck stays bent.
What buyers say
…apparently my neck has opinions about pillow height.
Once you shape it, it stays that way until morning.
It's easy to make small adjustments to make it fit perfectly.
The list most pillow makers hope you never read. None of it is in a Circadian pillow.
Tap any one to see where they posted it.
Check it yourself
A certification you cannot verify is a logo. Here are ours, with the numbers and the databases they sit in.
Whole pillow, end to end
Audits the fiber farm, the scouring, the mill and the workshop. On the Organic Cotton and Organic Wool pillows and both duvets, the fill and the cover are certified, not just the cover.
Licence GOTS-10229, audited on site every yearStrictest tier, finished material
An accredited lab tests the finished material against more than 100 harmful substances, including PFAS, formaldehyde, heavy metals and pesticide residue, at the threshold used for products made for direct contact with infants.
How Standard 100 worksUpstream, at the source
The Forest Stewardship Council audits the plantations the latex is tapped from against criteria for ecosystem protection, worker safety and land rights. OEKO-TEX tests the finished latex; FSC covers where it came from.
How FSC certification worksThree of our pillows are not GOTS Certified Organic and we say so on the certifications page, along with the reason for each. Read what each certification covers
Side by side
| Question | Circadian pillow | Molded foam pillow | Polyester fiberfill pillow |
|---|---|---|---|
| Height | You set it through the zipper | Fixed when it was molded | Starts tall, then goes flat |
| If you change how you sleep | Take some out or put it back | Stays one height | Stays one height |
| What touches your face | An organic cotton cover | Varies | Varies |
From the founder
Every pillow I tried either flattened in three months or hid a list of chemicals you'd need a glossary to read, so we built one that doesn't do either.Jacob, founder of Circadian
The same hands have been making pillows in this New Jersey workshop since 1981.
A few last questions
Enough to fill the space between the point of your shoulder and your ear, so your ear sits about over your shoulder. That space depends on how broad your shoulders are, which is why no single height suits every side sleeper. Every Circadian pillow arrives full so you can set yours.
A soft, low one. A tall pillow tips your head back and holds your neck bent all night. The Wild-Harvested Kapok Pillow is the softest we make, and any of our pillows can be taken down low through the zipper.
One that fills the small hollow behind your neck, so your chin stays off your chest and your head sits level with your shoulders. That takes less height than side sleeping, so plan to take some out.
Set the height for the position you spend most of the night in. If your neck wants something different from night to night, the Buckwool Hybrid Pillow has firm buckwheat on one side and soft wool on the other, and you flip it.
Any time. Keep what you take out and put it back if the pillow starts to feel low. We also sell refills for every pillow.
Sleep on it for 60 nights. If it isn't your pillow, send it back for a full refund. Most orders arrive in 5 to 10 business days.
Not sure which fits you
Six natural fills, each in an organic cotton cover, each sewn by hand in New Jersey and shipped free.
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