Here’s my totally honest, no-nonsense review of the Lumen device after using it for the past three months. I went into this with a mix of curiosity and scepticism, wondering if a little breathalyzer-like gadget could actually help me understand my metabolism better. Now that I’ve put it to the test, I’ve got a lot to share. And if you’re thinking about trying it for yourself, don’t forget to use discount code GYMFLUENCER10 for 10% off.
My First Impressions
Let’s kick off this review of the Lumen device but talking about how excited I was when it first arrived. The packaging was sleek, the device itself felt high-quality, and setting it up was ridiculously easy. You just charge it, connect it to the app, and within minutes, you’re taking your first breath measurement.
The app walks you through how to use it, explaining that Lumen measures the CO2 levels in your breath to determine whether your body is burning carbs or fat. That’s when it hit me—this thing could actually give me real-time feedback on how my metabolism is working.
Using Lumen Daily
I started my Lumen journey by taking morning readings before eating or drinking anything. The app would then tell me whether I was in fat-burning or carb-burning mode, which gave me a clear idea of how my metabolism was functioning.
At first, I was just excited to see the numbers. But after a week or two, I started noticing patterns. On days when I ate more carbs the night before, I woke up in carb-burning mode. On nights when I had a lower-carb dinner, my body had switched to fat-burning by morning. It was kind of wild seeing my metabolism react in real time.
I also used Lumen before and after workouts to see how my body was fuelling itself. Some days, my readings told me I needed more carbs to push through a high-intensity session. Other days, I learned that I could go fasted without feeling sluggish. This was one of the biggest game-changers for me, and definitely something I wanted to mention in this review of the Lumen device.

What I Loved About the Lumen Device
One of the other main things I have to mention in this review of the Lumen device is how easy it is to use. The app is super intuitive, and the daily insights actually helped me tweak my nutrition and workouts in a way that felt sustainable.
- It showed me exactly how my body responds to different meals.
- It helped me figure out the best way to fuel my workouts.
- I learned how to shift between burning carbs and fat more efficiently.
Most importantly, it made me aware of my metabolism. I wasn’t just following some generic diet plan—I was making choices based on what my body actually needed.
The Downsides
No product is perfect, and I know this review of the Lumen device needs to be balanced, so here’s what I didn’t love about it.
- You have to be consistent with taking your readings. If you forget for a few days, it’s harder to see trends.
- The breath measurements take some getting used to. You have to inhale and exhale in a controlled way, and it took me a few tries to get it right.
- If you’re expecting instant results, this isn’t a magic weight-loss tool—it’s a metabolic tool. You still have to put in the effort.
My Review of The Lumen Device – Is It Worth It?
Let me wrap up this review of the Lumen device by saying this – if you’re the kind of person who loves tracking your health and making informed choices, then yes, Lumen is absolutely worth it. It’s not just about weight loss—it’s about understanding how your body works and using that knowledge to optimize your metabolism, workouts, and energy levels.
After three months, I genuinely feel like I have a better handle on how my metabolism functions. I’ve made small but meaningful changes to my eating habits, and my energy levels have never been better. I also love that Lumen helps me avoid unnecessary carb-cutting or restrictive dieting because I can see exactly when my body actually needs them.
And if you’re thinking of trying it out after reading this review of the Lumen device, now’s the perfect time. Head to the Lumen website, use the discount code GYMFLUENCER10 for 10% off and see for yourself what it’s all about.



