The Ultrahuman Air Ring Review
I bought the Ultrahuman Air Ring in February 2025.
Not because I needed another wearable, although I do love shiny tech.
But because, as someone with PCOS who tests wearables for a living, I really wanted this one to work. An Oura ring alternative with no monthly subscription? Sign me up!
I’ve spent years teaching fertility awareness, charting long and irregular cycles, and cross checking biomarkers the old fashioned way. I also understand why people want wearables to work.
And to be fair, wearables can be helpful in certain contexts.
So when Ultrahuman positioned the Air Ring as a sleek, subscription free alternative to Oura, I was interested. I don’t love the idea of paying a monthly fee just to access my own data.
All in all, if you’re looking for a general health, sleep, and movement tracker, the Ultrahuman Air Ring holds up.
If you’re hoping to reliably track basal body temperature or ovulation, especially with PCOS, you’ll want to read this entire post.
Context Matters: Who This Review Is For
Before I get into the details, it’s important to say that I’m reviewing the ring as
a fertility awareness educator
someone with PCOS and long, irregular cycles
someone who cross referenced the data against Tempdrop
someone who understands how ovulation is actually confirmed and the difference between that and an algorithm giving you your estimated fertile window.
This is a fertility charting based review.
Where the Ultrahuman Air Ring Did Well
Sleep Tracking
Let’s start with what it did do well, because there are strengths here.
Sleep tracking was genuinely one of the best parts of the Ultrahuman experience.
The data felt accurate and consistent with how I actually felt day to day. Sleep stages, duration, and recovery trends were intuitive and easy to interpret. If you like nerding out (and stressing over) sleep, this was a win.
Step Tracking and Movement Nudges
As someone who works from home and spends a lot of time sitting, the gentle nudges to move were helpful.
Steps, daily movement worked reliably. The ring doesn’t auto-detect other activities other than steps.
It motivated me to get up, stretch, and walk which I feel overall was a positive.
Interface and User Experience
The app itself is clean, modern, and easy to navigate.
The data is presented clearly. From a UI standpoint, Ultrahuman did a nice job here.
If you’re looking for a subscription free health tracker for sleep and movement, I get the appeal.
Where It Fell Apart: Fertility Charting
When it comes to the cycle tracking side of things, this is where Ultrahuman didn’t do a great job.
Because while the ring markets itself as a cycle tracking, what that actually looks like in practice matters, and this is where it lost me.
It Could Not Reliably Detect Ovulation
Ovulation confirmation is not about fertile window predictions, it’s about confirming ovulation based on fertility biomarkers that the tech is tracking. When we’re looking at temperature as a sign of ovulation we’re looking specifically at:
a sustained temperature shift
interpreted in context
ideally cross checked with another biomarker
Across the cycles I tested, the Ultrahuman Ring failed to consistently identify temperature shifts that were clearly present when cross referenced with Tempdrop.
Sometimes shifts were missed entirely and other times, the data was incomplete or delayed.
Data Gaps Made Interpretation Impossible
I went through multiple rings due to hardware issues (more on that below), which meant extended periods of missing temperature data while waiting for replacements.
This matters because BBT is about consistency. Missing chunks of data break the pattern you’re trying to interpret. And even when temperatures were elevated due to ovulation, the algorithm often didn’t register a clear shift.
Retrospective Cycle Interpretation Is Not Fertility Awareness
In one cycle where the app did identify a luteal phase, it was marked retrospectively, based on the start of menstruation not on the actual real time temperature data.
That luteal phase was labeled as 26 days long. Which biologically, is not how luteal phases work, unless I was pregnant (which I wasn’t).
This is one of my biggest issues with many cycle tracking apps. If ovulation is “confirmed” after your period arrives, that’s just the calendar method.
For people trying to avoid pregnancy, retrospective confirmation alone is functionally useless.
The PCOS Factor (And Why It Matters)
To be fair, to give the device the benefit of the doubt, having PCOS complicates things:
longer follicular phases
more variability
more irregularity
It’s possible that someone without PCOS, with very regular cycles and pristine data, might have better results. But I get really hung up on this because devices that claim to track cycles should be tested against non textbook cycles, not just ideal ones.
PCOS is statistically common for a significant portion of the population, and fertility awareness tools need to work for us too, not just in perfect 28 day cycles.
The Bigger Deal Breaker: Hardware Issues
Even if the fertility data had been mediocre but improving, I might’ve stuck with it longer, but this is where the experience fully broke down.
Four Rings. Multiple Battery Failures.
I went through three rings with battery issues and the fourth ring wouldn’t reliably stay connected.
Each time, the process looked like this:
device stops syncing
reset required
wait several days to re pair
briefly works
glitches again
When you’re collecting daily temperature data, that kind of instability is really really annoying.
After the fourth ring, I requested a refund.
The State of Wearables for Fertility in 2026
Wearables are everywhere, but based on what I’ve tested personally and cross referenced with real charts, here’s where things stand for me right now.
Devices I’ve Tested
Tempdrop
Still my top pick for BBT accuracy, especially for long or irregular cycles. Read my updated Tempdrop review.
Apple Watch
When I tested it across three cycles, it was roughly 66 percent accurate when cross checked with other signs.
Ultrahuman Ring
For me, accuracy for ovulation detection was effectively zero when cross referenced with Tempdrop.
Devices I Haven’t Personally Tested
Oura Ring and the Natural Cycles wristband are big ones that I get a lot of questions about. I’m testing the Natural Cycles band next, so stay tuned.
What I do recommend, regardless of device, is this:
Always cross reference any wearable with oral BBT for at least two cycles before relying on it, and never trust app interpretation without understanding the underlying signs.
Proceed With Caution (And Curiosity)
Here’s the thing I want to be very clear about: wearables can be super helpful, but no device currently replaces your own understanding of your cycle.
Temperature alone is less reliable for pregnancy avoidance than:
temperature plus cervical mucus
interpreted by a human
with context
If an app tells you that you’ve ovulated, stay skeptical and ask how it knows.
What’s Next for This Perpetual Experimenter
For now, I’m honestly considering buying a second hand Fitbit purely for step tracking. I’m also testing the Natural Cycles wristband next, so stay tuned!