Noise Luna Ring review: A comprehensive health tracker, with one big catch

The Noise Luna Ring is a smart ring with all the convenience of a finger-worn lifestyle tracker, but with the battery life of a smartwatch, and it threatens to turn what should be an easy-to-live with wearable into a bit of a chore. But do the features and data it delivers make up for the short battery life? I’ve found out over the past few weeks.

Noise Luna Ring: design

Noise has done the impossible with the Luna Ring. It has made a titanium finish feel, and even look, a bit like plastic. I had to double check what material was used in the Luna Ring’s construction, just to make sure I wasn’t mistaken, but it is titanium. However, the decision to make it super smooth and to apply a Physical Vapor Deposition (PVD) coating seems to have robbed it of a high quality feel.

A PVD coating is supposed to add scratch resistance, but don’t expect too much as even after a couple of weeks, the surface of the Luna Ring is covered in micro scratches. You can’t spot them from a distance, but up close it’s very noticeable. I’m wearing the Stardust Silver version, but you can also get a black model, and both a Rose and a Sunlit Gold version. It’s available in sizes six to 13, which is less varied than the Oura Ring 4 and the RingConn Gen 2.

I’m also confused about the dimensions of the Luna Ring. It’s stated the ring is 2.8mm thick and 8mm wide, which is about the same as the Oura Ring 4, but there’s something to do with the shape that makes it feel bigger between my fingers. Additionally, the finish is slightly “sticky” meaning I’ve been more aware of the Luna Ring than other smart rings. It’s not uncomfortable, but it is noticeable, and that can be just as bad.

I appreciate the wave-like design flourish on the top of the ring, and that the underside is completely smooth, just like the Oura Ring 4. Not using nubbins to hide sensors makes the smart ring look more normal and feel more natural. I’ve worn it almost 24-hours a day since I started reviewing it and have not had any allergic reaction, or noticed that it makes my finger sweaty. I chose a size 11, which matches most other smart rings I’ve worn, and it fits snugly and true-to-size. The Luna Ring’s shiny, smooth, yet oddly sticky surface doesn’t look or feel like titanium, and instead it feels a bit cheap which for smart jewelry is a crime. It’s a shame, as the rest of the smart ring’s design and construction is excellent.

Noise Luna Ring: what does it do?

The sensors on the smooth underside of the Luna Ring measure your heart rate, blood oxygen level, and skin temperature, allowing it to track your sleep, activity, stress, and menstrual cycle. It also returns data points on your respiratory rate, resting heart rate, heart rate variability (HRV), and steps, plus delivering information on sleep stages. You can log calorie intake and hydration manually in the app too.

The Luna Ring has a manual workout tracking mode, where you can track individual activities, such as walking and running, cycling, badminton, football, tennis, and a freestyle workout. It also has automatic workout tracking, which has been moderately successful. However, it is quick to pause, leading to it showing multiple workouts to confirm when you open the app, when all you did was stop on a walk or run for a few minutes.

There’s also an AI coach called Luna, which is supposed to give personal recommendations about your health. The Luna Ring is not a medical device, so there’s only so far it will go in providing advice. For example, it will give general advice on recipes for low calorie snacks, improving HRV, or creating a workout plan. When you ask it how to lower your resting heart rate, it tells you to get more regular exercise and practice stress management. It’s possible to get more personal, such as asking it to analyze your sleep, but all it really does is summarize the data that’s already available. I didn’t feel drawn to using Luna AI very much.

Noise Luna Ring: is the app informative?

The Luna Ring’s app is well designed and easy to use. There are five options along the bottom of the screen, below a vertically scrolling list of different blocks showing your most recent data. Tap each one for a deeper dive. The graphs used are clear, and the information is sensibly spaced out so it’s all very easy to read. You can quickly see when you’re performing less than optimally, based on previous data collected.

There’s a Health Monitor block showing key sleep data points — respiratory rate, resting heart rate, HRV, Sp02, and skin temperature — and each gets a green tick or a red exclamation mark so you see at a glance if there are any issues. Throughout my test it has shown a red exclamation mark against blood oxygen, with the ring showing a 94% average saturation level, which is marginally under the normal 95% to 100% reading.

I’ve been wearing an Oura Ring 4 through the test, and it has shown readings between 96% and 98%. The language used in the Luna app is harsh and may be concerning to some, with the message “your blood oxygen is significantly low” shown in the Health Monitor window, despite the results being marginal. I’ve tested wearables for years, and none have shown my blood oxygen levels are below the normal level, leading me to question the Luna Ring’s accuracy here.

This aside, the feedback it gives is as you’d expect from a non-medical wearable. It shows a Readiness Score and a snippet of advice, like push harder or take a rest. There’s also a sleep planner, but the advice it gives here feels off for me. It says based on my “sleep debt” and goals, I should go to bed at 01:00 and wake up at 08:00. If I followed this plan, I know I’d be pretty useless during the day.

After tracking a workout it shows more information than the Oura Ring’s app, with maximum and minimum heart rate, cadence, distance, and time spent in different heart rate zones. It pulls GPS data from your phone and plots it on a map. The data recorded closely matches that returned by the Oura Ring 4 and the Apple Watch Series 10. For a smart ring, the Luna Ring makes a great casual fitness tracker.

In general the Luna Ring app is one of the better health tracking apps, and aside from a few accuracy and recommendation concerns, it has been reliable, syncs quite quickly, and shows me all the data I want. There’s no subscription charge for the app or its data.

Noise Luna Ring: battery and charging

To this point the Luna Ring has been a decent, if unremarkable smart ring, but unfortunately it’s about to lose some points. Battery life is always a key consideration for any wearable. If it’s too short, it’s on charge to often and people quickly tire of maintaining it, which can result in not wearing it at all. Noise claims four to six days battery life from the Luna Ring, but I haven’t come close to even four days battery in my use.

The Luna Ring’s battery lasts two or three days, depending on whether you track a workout or not. I initially wondered if this was due to it getting to know me, but the poor performance continues even after ten days, when it seems to have finished calibrating. This is very similar battery performance to my Apple Watch Series 10, less than the OnePlus Watch 3 by at least a day, half what I get from the Oura Ring 4, and a week less than the RingConn Gen 2 Air.

One night’s sleep and a 30 minute workout during the day sees 25% of the battery disappear by early evening, and it’s under 50% remaining by the following morning. The battery has completely expired without me knowing on several occasions, due to being taken by surprise by how short the battery life is, and the unreliable battery life warning notifications. It’s charged on a custom plinth, but the design is such that the ring never seats correctly, leaving you messing around with it until the charging light illuminates. It’s frustrating and unnecessary.

The best way to charge a smart ring is to do so when you wouldn’t normally wear it, such as when you’re in the shower, keeping the battery topped up so it doesn’t require a full charge. The Luna Ring just about survives like this, but there’s no room to forget for a few days, and you’d have to take the charger with you on vacation too. Considering all the other smart rings I’ve tested have at least twice the use time from a single charge, the Luna Ring is a very poor performer.

Noise Luna Ring: price and availability

The Luna Ring costs $300 from Noise’s own online store and does not require a subscription to the app. This makes it cheaper than the Oura Ring 4, which starts at $350 and has a $6 monthly subscription, the RingConn Gen 2 which is $360, and the $400 Samsung Galaxy Ring. It’s more expensive than the $238 RingConn Gen 2 Air.

All the above models are not only the Luna Ring’s direct competitors, but also more advisable purchases. Each has longer battery life for more versatility, and avoid the Luna Ring’s oddly plastic-like finish.

Should you buy the Noise Luna Ring?

The Luna Ring’s app is one of the best I’ve used, with plentiful easy to understand data, plus I like that it has lots of workouts to track including a freestyle option, and the ring’s hardware is built well. It’s a comprehensive lifestyle tracker for someone who casually exercises. However, the smart ring has terrible battery life and awkward charging from the poorly designed charging plinth. It’s this which lets the package down. Some may like or just accept the feel and finish of the titanium, but I don’t think it reflects the material used or the price of the smart ring.

It’s not a recommendation due to these downsides. If you want a smart ring our recommendation is to buy the Oura Ring 4 or the RingConn Gen 2, or if you want more fitness and activity tracking than sleep tracking, one of our best smartwatches will likely suit you better.

What’s more, Noise has recently announced the Luna Ring Gen 2 (or Luna 2.0) with a different design and a longer lasting battery. It’s currently available as a pre-order, and may be worth waiting to see if that model delivers if you like the look of Luna’s app.