Lumen Metabolism Tracker Review: Pros, Cons, and Does It Work?

This post may contain affiliate links. Read our disclosure policy for more details and read how our review process stands apart!

Welcome to my Lumen metabolism tracker review article, where I share how it works, pros, cons and if it actually does work.

lumen metabolism tracker rating by fit healthy momma

I tried this metabolism tracker. You actually breathe into the device shown in the image and then you get some real data. This is my rating of the product.

Fit Healthy Momma Rating: 8.2/10

Lumen is a revolutionary, pocket-sized metabolism tracker that’s helping people better understand their bodies and what role their unique metabolism plays in them. With personalized nutrition information, in-app lesions, and easy-to-understand metrics, Lumen is convenient and effective for those looking to gain better insight into their health and wellbeing.

$50 off coupon code: FITMOMBF

It feels like we’re all trying to find the latest trick to finally look and feel the way we want, right? As a personal trainer, wellness enthusiast, and realist, I’ll tell you that I don’t subscribe to the so-called hacks out there when it comes to your fitness and nutrition.

So when Lumen reached out and asked me to review their metabolism tracker, I was skeptical. I mean, can a little breathalyzer-type device truly give you access to accurate data relating to your metabolism and how it works? Can you hack your metabolism so that you can start to see the results you’re looking for?

I did a little digging before consenting and discovered that the reviews of Lumen out there are actually quite positive and enthusiastic. Being that I’m curious and obsessed with all things fitness and wellness, I agreed to review Lumen so that I could gain a firsthand experience and then share it here with you.

So let’s dive into everything Lumen, including the pros, cons, and whether or not I think it’s worth it.

Why Try to Hack your Metabolism? What Does That Even Mean?

The goal of the Lumen device is to “hack” your metabolism, but what does that mean? Well, the goal, they say, is to become capable of metabolic flexibility, which means that your body can efficiently shift from using carbs and fats as fuel. This is achieved through things like exercise type, macronutrient manipulation, and eating time frames like intermittent fasting.

Macro manipulation is the process of optimizing the amount of each macronutrient (protein, carbs, and fats) that you consume so that you can improve your insulin sensitivity and help your body burn more fat. Sounds complicated, right?

Here’s the deal, your breath can reveal if your body is burning fats or carbs at any given point in your day. The Lumen device uses a Co2 sensor and flow meter to determine the Co2 concentration in a single breath, which will then indicate the type of fuel your body is using to produce energy.

With this information at your disposal, you can then use the Lumen app to get a custom nutrition plan for each day that will align with your personal, long-term goals. If you want to take it a step further, try a CGM like NutriSense CGM - a wearable blood glucose tracker that provides in-depth data to optimize your health.

Quick Summary of Lumen Metabolism Tracker Review


Lumen Metabolism Tracker




Merav Mor, Michal Mor

Year Founded:



Discount Code:

Use code FITMOMBF for $50 off

Main Purpose:

To track your metabolism and bring personalized nutrition to people in a fast, efficient way.

Transparency Rating:

10/10 ⭐

Avg. User Rating:

4.6/5 ⭐ (Rating is considered "Excellent" and there are 1,993 reviews on Trustpilot)

FHM Overall Rating:

8.2/10 ⭐

Introducing Lumen: A Peek Behind the Brand

The Lumen team are “big believers in science, data, and you.” They believe that having a healthy metabolism unlocks the door to better health and that it’s attainable for all of us.

turning on the lumen device

The brand was founded by twin sisters, Merav and Michal, both Ironman winners and PhDs in physiology. Given their background, they were both passionate about nutrition and how to optimize it based on our unique, individualized needs. What they found was that the traditional ways of measuring metabolism are both costly and time-consuming.

So, like all entrepreneurs, they decided to solve the problem. Together with other experienced brand builders, they came up with the very first Lumen prototype after spending two years in the research and development stage. Their solution for hacking metabolism was to measure it in a single breath in less than a minute as opposed to doing so in an hour-long lab test.

Now, this tech is available to everyone, everywhere. Let’s get down to the nitty-gritty of how Lumen works and what the benefits are.

What Are The Benefits of the Lumen Device?

Lumen promotes metabolic flexibility, which is basically the ability of your body to switch back and forth between using carbs and fat for your fuel source based on their availability.

the lumen device

$50 off coupon code: FITMOMBF

Let’s talk about the benefits of Lumen and its ability to create metabolic flexibility:

Weight Loss

By improving your metabolism, you’re inherently cultivating an environment that will result in natural weight loss. With an optimized metabolism, you’ll be able to lose weight in a sustainable way.

Decreased Snacking

With Lumen, you can increase your body’s ability to burn fat, which will naturally decrease your hunger level and need for snacking throughout the day. Side note, this is by far the most challenging thing for me personally, so I love this benefit!

Improved Energy and Mood

With a high functioning metabolism, your energy levels will be up and your mood will lighten.

Better Overall Health

Improving your metabolic flexibility can help to prevent diseases like obesity, diabetes, and other metabolic syndromes.

Enhanced Weight Maintenance

It’s easier to maintain your weight when your body’s metabolic rate is optimized and burning fat properly.

Controlled Blood Sugar Levels

Blood sugar spikes can cause us to feel hungry, which leads to overeating and excessive snacks. Lumen lets you take control of your body’s ability to burn carbs so you can avoid these blood sugar spikes.

Understanding Lumen Levels and How It Works

This is perhaps the most perplexing part of the Lumen device; understanding what you’re reading and how you’re supposed to interpret it, so let’s break it down and answer some common questions, shall we?

reviewing lumen levels

This image shows the levels of lumen, from 1 through 5.

When should you take your Lumen measurement?


The most important and most insightful measurement of the day is your morning breath. When you are sleeping, your body goes into a resting state and you are also in a fasted state (no food or beverages). By measuring your morning breath, Lumen can gather all of the data it needs to prepare a personalized meal plan for you that specific day.

Pre & Post-workout

Measuring your breath before your workout will provide insight into whether or not your body needs to fuel up based on that activity’s intensity and duration. For example, if you’re planning an intense workout like a HIIT workout, your Lumen might indicate that you need to eat some fast-digesting carbs before starting your workout for optimal performance and results. After your workout, you should wait at least 30 minutes before taking another measurement to be able to see the impact that your workout has on your body.

After Meals

Take your measurements 1-2 hours after each meal to get an idea of how your body responds to certain foods.

After a Fast

This can mean first thing in the morning or, if you practice intermittent fasting, you can take your measurements after your fast to see how it impacted your metabolism.

Random Check-Ins

Every once in a while, it’s encouraged to check in with your breaths throughout the day. Doing so will help you to gain a better understanding of your metabolism and how it reacts and responds throughout the day.

When Do I want to Receive a High or a Low Lumen Level?

The Lumen levels can feel a bit overwhelming at first glance, so here’s my understanding. When you take your first breath into your device in the morning, you would ideally like to receive a Lumen level of 1 or 2 which would indicate that your body was burning fat while you were sleeping.

morning lumen levels best results

Then, when you eat a meal that contains carbs, you would want to receive a Lumen level of 4 or 5 indicating that you are burning energy from your food, not your fat stores. This is a good sign that your body recognizes that it’s been fed and is now using the energy you consumed as fuel.

The overarching goal is to achieve metabolic flexibility which is your body’s ability to switch efficiently between the two energy sources. In a perfect scenario, your body would use the fuel you eat during meals to power you through the day, then switch into a fat-burning mode at nighttime when you’re fasting.

What If My Levels Are Sub-Optimal?

Let’s say you measure your breath and your results aren’t looking like what they outlined here. Don’t panic! Here are a few tips and things to look out for.

question about sub optimal lumen levels
1. Make sure you’re at rest when measuring

If you’re trying to take your measurement when you’re running around, trying to get the kids out the door, or to work on time, your levels won’t be accurate. Try to find a minute or two to sit in peace in a comfortable chair and with a calm, relaxed mind.

2. You have low metabolic flexibility

We all start somewhere, so if your levels are really high starting out, know that the ultimate goal is to optimize them. If you’ve struggled with your weight and diet for months or years, then your metabolism is not likely to be super flexible right now. The best piece of advice is to stick with the nutrition plan outlined by Lumen and tryst the process, it takes time!

3. You’ve had a lot of carbs lately

Contrary to popular belief, your Lumen level is affected by your food intake for up to 3-4 days, not just within the last 24 hours. So, if you have eaten a lot of extra carbs (hello, pizza night!) within the last few days, chances are your body’s glycogen (carb) stores are full, so you’ll need to give them some time to empty before getting a more accurate reading.

4. You’re stressed

Stress can do some serious damage to our bodies, and most of us aren’t even aware it’s happening. By raising cortisol and adrenaline levels, your body automatically shifts into fight or flight mode which turns on the carb-burning mode instead of fat burn. To combat this, try meditation or lower intensity workouts.

5. You’re not sleeping well

Similar to the way stress can lead to an increase in cortisol, so can poor sleep. Even one night of a few missed hours can lead to your body’s response to kick into carb-burning mode.

All that said, if you’re still having trouble with your Lumen levels, the Lumen team is there to help. They have a chat option o their official website where you can get in touch with one of their experts anytime you wish

What Information is Available on the Lumen App?

The Lumen app is not only where you’re able to record and track your breathing and metabolic rate, it’s also the center of all your personalized information, insights, and recommendations for optimizing your life.

information on lumen app

This is the route I chose in the lumen app.

Lumen’s dashboard has information including a personalized nutrition plan, monthly cycle tracking (for females), your Breath signature, daily measurements, weekly goals, and more.

Next, let’s dig into the personalized nutrition plan that’s based on your physiological needs.

Personalized Nutrition Based on Your Physiology

The Lumen device takes the guesswork out of figuring out what to eat and when to eat, all based on your personal physiology. With this guidance, you’re better prepared for what to expect and subsequently, how to stay on track with your meals and snacks. An understanding of how your diet affects your body is crucial to dialing in your nutrition and making sure it’s working for you and not against you.

personal nutrition plan on lumen app

The three key features of the nutrition information include:

  1. Personalized meal recommendations
  2. Real-time daily metabolic insights
  3. Sustainable, custom-tailored meal plans

Cycle-Specific Information and Tracking

For women using Lumen, we can put our menstrual cycle information into the app and it will not only track the phases of our cycle, but it will also provide us with insights and information relating to what and how we should be eating based on where we’re at in our cycle.

For example, as I was writing this review, I was on day 8 of my cycle, which is considered phase 2. During this estrogenic phase (high estrogen levels), Lumen recommended that I eat all my daily carbohydrates before dinner as it makes it easier for my body to burn fat.

I have always struggled with having a normal menstrual cycle, so now that I do, I am super into finding ways to optimize my body, nutrition, and life around the phases of my cycle. I truly appreciate the insights and guidance that Lumen offers in this super-important area of women’s health.

Lumen and Women’s Health - New Features & Benefits

Lumen recently added even more advanced women’s hormone health tracking and insights into the Lumen app. Women can now utilize the menstrual cycle tracker and menopause insights, depending on what stage of life their in, to gain a deeper understanding of their bodies and how to optimize their nutrition throughout the month.

Female users can indicate inside the Lumen App what day of their menstrual cycle their on, how long their average cycle length is, and how long their cycle typically lasts. Updating this information inside the app allows Lumen to offer feedback, suggestions, and insights into your cycle that will play a role in your nutrition. 

The same goes for menopausal women. Inside the app, you have the ability to indicate which stage of menopause you’re in (perimenopause, menopause, or post-menopause and whether or not you’re taking HRT (hormone replacement therapy).

With your menstrual cycle or menopause settings in place, you’ll begin to get daily or weekly tips and insights that will help guide your nutrition and exercise choices so that you start to see the effects of your natural hormonal fluctuations and begin to explore your metabolism’s reaction to your cycle. The more you track and pay attention to your cycle, the stronger the connection will be between your metabolism and your habits. It’s just one more way to connect the dots and feel your best. 

How Does Cycle Tracking With Lumen Work?

It’s really simple to track your cycle inside your Lumen app! Here’s how to get started:

  • Step 1 Go to your “Me” tab
  • Step 2: Go to the personal info area.
  • Step 3: Tap the monthly cycle area.
  • Step 4: Indicate that you would like to track your monthly cycle and enter the start date of your last period, the average duration of your person, and the average duration of your cycle.
  • Step 5: Click save. The monthly cycle area will now display your current cycle phase.

Once you’ve entered your cycle information, you will then be able to see your monthly cycle card on your “today” screen dashboard. This card will show you what phase of your cycle you’re currently in and will provide you with recommendations based on your cycle and metabolism.

It’s important for women to understand their menstrual cycles and how each phase affects their energy and metabolism. Lumen’s cycle tracking functionality is making understanding our cycles and how we can tailor our habits to it can truly help us to feel our best all month long.

Breath Signature

Inside the app, you’ll also gain access to your unique breath signature. This is your metabolic measurement taken over time. With continued use, your Lumen levels will get more accurate.

Lumen recommends that you take daily morning measurements as well as follow the Breath Signature instructions so that you can get to your goals most efficiently.

Daily Tracking

Each day of the week, you can check in with your daily summary to see your progress and determine what specific targets you need to hit. The information within this area of the Lumen app includes:

  • How many carbs and/or fat servings you should be aiming to get each day per your metabolic rate and goals
  • Planned overnight fasting period
  • Your current Lumen levels as measured by your breath
  • Monthly cycle day and phase
  • Your sleep information (which will pull from your Apple Health integration)
  • Workout information (which you will add yourself from the home screen)
  • A section for daily notes (on this particular day, I would add a note that my sleep was off due to my toddler waking in the night)

Workout Tracking

If you take the time to pre-plan your workout schedule, Lumen will increase the number of recommended carb servings to your daily nutrition plan to accommodate the extra intensity and exertion.

How to Take Your Lumen Level Measurement

The best part about Lumen and their app is that they really hold your hand throughout the whole process, so you don’t have to worry about feeling lost or confused.

When it comes to taking your measurement, aka breathing into your Lumen, you’ll be guided by the app on how to proceed. You’ll start by taking in a deep breath where you’ll be able to track it on the screen of the app. You need to keep the green ball inside the target zone. If you mess it up, you’ll get feedback on how to do it better and will be prompted to try again.

After your inhale, you’ll remove your mouth from the Lumen and hold your breath for 10 seconds. On-screen, you’ll be queued to when you’re to exhale back into your Lumen. When it’s time to exhale, you’ll do something similar in that you’ll be aiming to get the green ball inside the middle of the target.

It sounds more difficult than it is. Once you do it a couple of times, you’ll get the hang of it and it’ll only be a minor disruption to your normal schedule.


  • Helps users to optimize their nutrition and understand their metabolism
  • A comprehensive app that connects to the device seamlessly
  • Cycle, workout, and sleep tracking
  • It’s a small, discreet device
  • Might be able to help the user lose weight through specified nutrition and adherence
  • There’s plenty of support and interactivity available to help you understand what to do and how to process your measurements


  • Carrying Lumen around throughout the day is inconvenient (although it’s small enough for your pocket or purse)
  • The breath required to get an accurate measurement is big (could be difficult for some?)

How Much Does Lumen Cost?

Currently, Lumen offers three different “tracks” that you can choose from. Here are the details on the three options:

cost of lumen and pricing model

The Lumen costs are as follows based on information from their website, as this image shows the Metabolism booster costs $249, the Advanced Fat Burn costs $259, and the Optimal Health costs $349

Does Lumen Require a Subscription?

Yes, Lumen requires you to pay for a subscription to their app. You can choose from a 6, 12, or 18-month track (subscription) and it will automatically renew once the term is up. The subscription grants you access to the Lumen app, tracking, and personalized insights and information related to your nutrition and metabolism.

Real Lumen Metabolism Tracker Ratings and Reviews

As we do with every review we write, we like to source the internet and other user reviews to see what real users are saying about the product. One thing that I will say about Lumen is that this technology is still fairly new, so it’s tough to read the pulse when reviews are limited.

That said, I did discover that, of those who have spoken about Lumen, the vast majority of them are incredibly happy with their device and the results they’re seeing. So many of us struggle with nutrition and knowing what to eat and when. There are so many different takes on diets and what works and what doesn’t on the internet that I think we get trapped in an endless cycle of trying random things hoping one of them sticks.

The overall sentiment from Lumen users is that they are elated to be able to get unique, personalized insights into their body, how it works, and then actionable steps on how to optimize it. This is not a one size fits all diet program, rather, it’s a device + app that has the ability to help you reach your goals based on your physiology. 

This is a trend that I have seen come to the surface more and more lately when it comes to weight loss and I personally think it’s brilliant. Gone are the days of standard diets that don’t take into account individual needs. Science is allowing us to be far more intentional with our bodies and the way we set ourselves up for success.

So, Does Lumen Work for Hacking Your Metabolism?

Based on my experience, yes, it does. Is it a great tool for gaining valuable insight into your body and how it’s currently working. Armed with the data, Lumen then provides you with actionable steps to optimize your nutrition and metabolism for optimal fat loss results.

holding lumen getting ready to use it

Is it a magic cure for losing excess weight and keeping it off? Of course not! Lumen is a tool, that if used properly, can provide you with the framework for improving your health and metabolic rate. You still have to put in the work!

Using Lumen correctly for “hacking” your metabolism requires you to understand and adhere to the nutritional guidelines given to you by the device. Furthermore, you’ll need to spend some time tracking, measuring, and adding in other tools like exercise to see the best results possible.

Final Call: Is Lumen Worth It?

Lumen is worth trying out if you’re someone who is struggling with weight loss and would like to better understand your unique body and how it works. For those of us who enjoy the data and the numbers, Lumen is well worth the investment. It’s important to keep in mind that this isn’t going to be a cure-all for your weight and metabolism problems, it’s a tool and should be used as one.

all the products in lumen box worth it

When I first received my Lumen device, I went to my Facebook group and asked them what they thought about a device that could help them gain valuable insights about their metabolism and how to optimize it. The response I got was of genuine interest and curiosity. Is it worth $300? That depends on whether or not it works, and this is dependent on your willingness to use the device properly and take the information and feedback and turn it into results.

If you want my honest opinion, I think the Lumen device is incredibly cool and one that I will definitely continue to track to see if I can truly improve my metabolism and the way my body processes fats and carbs. If nothing else, I now have a much better understanding of what and when my body should be doing what with the fuel it has, which is incredibly valuable for someone who cares about their body and looking and feeling their best at all times.

We all have to eat, we might as well be doing so efficiently! The daily feedback you get just might be the missing puzzle piece that helps you lose weight and keep it off for good - finally!

Are you going to try Lumen? The great news is that you can try it risk-free for free for 30 days. If you don’t like it or find it useful, you can return it no questions asked. Also, they so generously gave me a code to share with you!

$50 off Lumen coupon code: FITMOMBF

Fit Healthy Wife

A devoted mother to two vibrant children, Fit Healthy Wife embodies the essence of health, fitness, and wellness. Juggling the demands of motherhood and professional commitments, she is a testament to the power of a balanced lifestyle. As the co-founder of Fit Healthy Reviews, she brings a touch of femininity and genuine personal experience to every product review. Her passion extends beyond just fitness, aiming to inspire and guide others on their wellness journeys. Due to her professional career, she will remain anonymous to protect herself and her family!