Does a wool pillow help you sleep better? I let WHOOP score 173 nights to find out.
In a development few saw coming, the founder of Circadian has concluded that Circadian makes a good pillow. I know how that sounds, so I brought receipts. Across 144 nights at home on the Circadian Organic Wool Pillow, I averaged 88.4% sleep performance and slept 7 hours 58 minutes a night. The average WHOOP member scores 82% and sleeps 7 hours 11 minutes. On the nights I slept away from my pillow, I scored 82.0%, right back with everyone else.
- On 144 nights at home on the Organic Wool Pillow, from April 2 to October 4, 2026, I averaged 88.4% WHOOP sleep performance. WHOOP's published member average is 82%.
- I slept 7 hours 58 minutes a night, 47 minutes more than the 7 hours 11 minutes the average WHOOP member sleeps.
- 106 of 144 home nights (74%) reached 85% or better, the level WHOOP says is enough sleep to perform. On 29 nights away from the pillow, 10 did (34%).
- 141 of 144 home nights (98%) met the National Sleep Foundation's mark for good sleep quality, asleep for at least 85% of the time in bed.
- Every night is counted, including five nights with a red recovery score.
I am the least neutral person who could run this study.
Every pillow company says its pillow helps you sleep, and so would I. That is the problem with asking a founder. So I took my opinion out of it and let WHOOP do the scoring.
The Organic Wool Pillow arrived at my door on April 1, 2026. From April 2 to October 4, WHOOP scored 173 of my nights. I slept 144 of them at home on the wool pillow. The other 29 were away from home, on whatever pillow the bed came with.
Hayleigh's evening routine ends on her Organic Wool Pillow. She presses it, opens the zipper to show the layers of wool inside, and goes to sleep.
33 seconds, with sound
On the pillow, I beat the average WHOOP member on all six of these numbers.
WHOOP publishes what its members average, and that is the fairest yardstick there is for my nights, because it is the same device doing the measuring. WHOOP's sleep performance score compares the sleep you got with the sleep your body needed that night, so 100% means you got all of it.
| WHOOP measure | Me, at home on the Organic Wool Pillow | Average WHOOP member |
|---|---|---|
| Sleep performance | 88.4% | 82% |
| Time asleep | 7 h 58 min | 7 h 11 min |
| Share of time in bed spent asleep | 92.6% | 89% (7 h 11 min of 8 h 2 min) |
| Recovery | 68.4% | 58% |
| Heart rate variability (higher is better) | 98 ms | 65 ms for men, 62 ms for women |
| Resting heart rate (lower is better) | 44.9 bpm | 55.2 bpm for men, 58.8 bpm for women |
How we checked this table: my figures are averages of my own WHOOP nights at home on the pillow, April 2 to October 4, 2026. The WHOOP column is quoted from WHOOP Member Averages, updated May 15, 2026. Download every night as a spreadsheet (CSV).
WHOOP's 2025 Year in Review adds two more yardsticks. Its best-sleeping generation, Gen Z, averaged 7 hours 4 minutes a night, 54 minutes less than my home nights. Its most consistent sleepers, the Boomers, averaged 71.4% sleep consistency, which measures how close your bedtime and wake time land from one night to the next. Mine was 77.0%, so I now keep a steadier bedtime than the average WHOOP Boomer.
There is an outside standard too. In 2017 the National Sleep Foundation set its mark for good sleep quality at asleep for at least 85% of the time you spend in bed. 141 of my 144 home nights cleared it.
Away from the pillow, I sleep like everyone else.
Over the same six months, with the same sleeper and the same WHOOP, my average only fell back to the WHOOP average on the nights I spent somewhere else.
| WHOOP measure | Home, on the Organic Wool Pillow | Away, same months |
|---|---|---|
| Nights tracked | 144 | 29 |
| Average sleep performance | 88.4% | 82.0% |
| Nights at 85% or better | 106 of 144 (74%) | 10 of 29 (34%) |
| Nights at 90% or better | 66 of 144 (46%) | 4 of 29 (14%) |
| Average time asleep | 7 h 58 min | 7 h 49 min |
| Sleep consistency | 77.0% | 68.7% |
Travel is hard on sleep, and WHOOP's own research with CLEAR found people lose about an hour of sleep the night before a flight. So I checked the trips inside the US on their own. On those 19 nights my sleep performance averaged 82.5%, still almost six points under my home nights on the pillow, and only 7 of 19 reached 85%.
I also wanted to know whether the home and away gap could be luck. I shuffled all 173 nights into random home and away groups 20,000 times, and a gap in good nights that wide came up about once in every 4,000 shuffles.
You stay asleep when the pillow stays dry.
The wool pillow is naturally cooling, and staying cool is a large part of staying asleep. Most people who wake up hot never feel the heat building. They kick off the covers and surface out of deep sleep without ever fully waking.
Wool keeps a pillow cool by moving moisture. It can take in up to 30% of its own weight in moisture vapor, which keeps the surface under your head cool and dry. It pulls the damp up from the organic cotton under your cheek and lets it go into the room. The heat leaves with it. A pillow that gives its heat away stays cool through the night, and the person on it has one less reason to come up out of deep sleep.
If you want the body side of that story, our guide to body temperature during sleep explains why your skin warms up as your core cools down.
I left the bad nights in.
Five of my 144 home nights came in with a red recovery score, WHOOP's lowest band. All five were weekend mornings, and I have my suspicions about what happened the night before. I kept every one of them. Taking them out would have raised my average sleep performance by 0.3 points, from 88.4% to 88.7%, and a founder grading their own homework should not get to pick which pages count.
Naps are the only thing missing, because WHOOP scores them separately. Every figure above comes from a full night's sleep.
How we checked
- Study type: a single-sleeper observational study (n of 1). Nights at home on the pillow are compared with WHOOP's published member averages and with my own nights away from it over the same months.
- Sleeper: Jacob Katz, founder of Circadian. Yes, the same one.
- Device: WHOOP, worn to sleep on every night counted here. Sleep and recovery records were downloaded through WHOOP's developer API.
- Window: April 2 to October 4, 2026. The pillow was delivered on April 1, 2026, per the order record.
- Home or away: decided night by night from my calendar and from the time zone WHOOP records with each sleep.
- Nights: 173 scored nights, 144 at home and 29 away, 19 of those inside the US. Naps were excluded. No other night was removed.
- Good night: WHOOP sleep performance of 85% or better, which WHOOP's Sleep Planner describes as enough sleep to perform.
- Statistics: a permutation test with 20,000 random shuffles of the home and away labels.
- Benchmarks, quoted as published: WHOOP Member Averages (updated May 15, 2026); WHOOP Year in Review 2025 (December 8, 2025); the National Sleep Foundation's sleep quality recommendations in Sleep Health (2017); WHOOP and CLEAR on travel and sleep.
- Conflict of interest: complete.
Frequently Asked Questions
Does a wool pillow help you sleep better?
On 144 nights of my own WHOOP data at home on the Circadian Organic Wool Pillow, I averaged 88.4% sleep performance against WHOOP's member average of 82%, and 74% of nights reached 85% or better. On 29 nights away from it in the same months, I averaged 82.0%. Wool takes in moisture vapor and lets it go, which keeps the surface under your head from warming up through the night.
How much sleep did you get on the Organic Wool Pillow?
An average of 7 hours 58 minutes a night across 144 nights at home, from April 2 to October 4, 2026. That is 47 minutes more than the 7 hours 11 minutes WHOOP reports for its average member.
What is a good WHOOP sleep performance score?
The average WHOOP member scores 82%, according to WHOOP's published member averages. WHOOP's Sleep Planner sets three targets: 100% of your sleep need to peak, 85% to perform and 70% to get by. My home nights on the wool pillow averaged 88.4%.
Isn't sleep always worse when you travel?
Often it is, which is why WHOOP's own member average is the main yardstick here rather than my trips. My away nights scored 82.0%, almost exactly WHOOP's 82% member average. Counting only trips inside the US, I averaged 82.5%, against 88.4% at home on the pillow.
Isn't it biased for the founder to test the pillow?
Completely, which is why the founder did not do the scoring. WHOOP scored every night, the method is listed above, and every night from April 2 to October 4 is counted, including five nights with a red recovery score.
Is a wool pillow good for hot sleepers?
Yes. Wool keeps a pillow cool by moving moisture, taking in up to 30% of its own weight in moisture vapor and releasing it into the room. The heat leaves with it, so the surface under your face stays cool and dry all night.
Founder recommends product. Organic wool inside an organic cotton cover, set to your height through the side zipper, with 60 nights to decide.
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