Urine strips, Ketone Blood Monitor, or Ketone Breathalyser? I get this all the time… What is the best way to test ketones? In this post, I will not only give you my view on this, but I will also show you how I maybe have found my new favourite way to test ketones.

I am so excited to share my review of the Ketoscan Mini with you. I must confess; initially, I was a little reluctant to give it a try as I was convinced the only accurate way of measuring your ketones was with a blood ketone monitor. They do say the blood monitor, testing beta-hydroxybutyrate is the gold standard of testing for ketones. So, why would I be interested to test ketones any other way?

Full disclosure: Ketoscan Mini initially reached out to me wanting to start the keto diet themselves. After exchanging a few emails and meeting up for coffee, they were so kind as to give me a Ketoscan Mini to test out and in turn provide them with my thoughts on it.

For the last couple of years, I have been using a blood monitor to test my ketones. I started out using urine test strips, like most others would, and then progressed onto the Freestyle Neo blood ketone monitor. Later on I started wholesaling the On Call GK Dual Blood Glucose Monitors, which I still use today.

After using the Ketoscan Mini for several weeks, I am really excited to share my experience and write this review. Hopefully, others will find it useful when deciding which method of testing is the best for them.


I also want to say that the Ketoscan Mini is not the first breathalyser monitor I’ve had the opportunity to test out. Over the past couple of years, I have tested two other breath monitors, which needless to say, didn’t impress me at all and didn’t compare with the Ketoscan Mini. I’ll highlight some of the things I think are important to consider when you are purchasing a breathalyser a bit further on in this post.

You can purchase some inexpensive breath ketone monitors on Takealot and other sites like Amazon. In my opinion and experience, you honestly don’t want to buy a cheaper monitor. As mentioned just now, I have tested two other models, and there is just no comparison to the Ketoscan Mini. The cheaper models were so wildly inaccurate and difficult to use that I got frustrated and didn’t have much confidence with the unreliable readings. I would, for example, do a breath test and the Monitor kept showing zero ketones in my breath whereas my blood monitor would show blood ketone levels of way beyond nutritional ketosis (1.2mml/dL). That just didn’t add up. I tried several times and just found it frustrating, and I lost my confidence in the breathalysers.

Another thing to keep in mind is that these cheaper breath ketone models do not have an app as the Ketoscan Mini has and the app is where the business is at. You want to be collecting data and tracking your results.

Another drawback (for me) on the cheaper models is that some of them use a battery whereas the Ketoscan Mini charges with a USB cable.


Before starting out with testing your ketones, I think it is important to establish where you are in your keto journey. If you’re just starting out with the keto diet, or in the initial stages of going keto, I think it is perfectly fine to test for ketones using urine test strips. As you advance and become what we call fat-adapted, you really want to move towards using blood ketone monitors or the breathalyser. If you have a lot of weight to lose and you are very intentional with keto and perhaps doing fasting, then testing is a must. Making use of urine strips won’t be effective though.

Testing For Ketones | Lean Fit Keto
Ketone Monitor - Ketoscan Mini Review | Lean Fit Keto

Why are urine strips not as accurate in the long run?

Urine strips are not as accurate in the long run or as you become keto-adapted. Here’s why.

The body produces ketones when carbohydrates are restricted or limited to below 20g per day. It takes the body about 5 to 7 days to start producing ketones. Ketones are produced from body fat that is broken down and converted into these ketone bodies by the liver. 

The Ketone bodies found in the body are:

  1. Acetoacetate – also referred to as AcAc
  2. Acetone
  3. Beta-hydroxybutyrate
Test Ketones
Ketone Monitor - Ketoscan Mini Review | Lean Fit Keto

Side note: Most people believe that the body produces three ketones, but that is not one hundred percent accurate and even though I also mostly refer to it as three ketones when speaking to people, just know that it is not entirely correct. It is necessary to explain it here in order for you to understand how the breathalyser works. 

How it actually works when your body produces ketones, is that your liver produces two ketone bodies initially. AcAc and Acetone. BHB comes from excess AcAc. 

As you start out on keto, Acetoacetate can be measured in your urine. Acetone is a breakdown of Acetoacetate and Acetone is expelled through your lungs. Acetone is the ketone body expelled through your lungs and what is detected and measured by the Ketoscan Mini’s sensor. Beta-hydroxybutyrate is the ketone body that is found in your blood and measured with a blood ketone monitor.

Once you become fat/keto-adapted, your body produces fewer ketones or also starts utilising the ketones better. As you advance and become really fat-adapted, there is a time when the body actually starts using fat directly, but that is for a whole nother post. 

Initially, the body produces a lot of ketones, the first of which is acetoacetate. Excess acetoacetate that is not used by the body spills out the body and can be measured with a urine strip. You have to understand that ketones are a valuable energy source and the body will calibrate how much ketones need to be produced and eventually used to sustain energy your requirements. As you become fat-adapted, your body will use the ketones, and fewer ketones will be detected in the urine. 

Another con or downside to testing ketones with urine strips is that they can be a bit unreliable. Things like dehydration hugely affect your urine test strip readings.


Firstly, there are a lot of people who are scared of needles. If you are one of them, then the Ketoscan Mini Ketone Breathalyser is your answer. 

Right up with this is the fear of blood. Some people are just grossed out by the sight of blood and blood ketone strips can be messy.

For me, I feel that it is a bit more convenient to use the Ketoscan Mini compared to the blood ketone monitor. Although I don’t test that often anymore, I would take my blood monitor with me when we are travelling. Testing my blood ketones when I am at home or in the office is great, but testing it somewhere where I would be over at someone’s house or at a restaurant is not something I would do in public. Whereas I feel a little more confident to be simply blowing into my breathalyser machine sitting in the middle of a coffee shop. So for me, being able to measure anytime, anywhere is definitely a pro.

Ketone Monitor

Accuracy of ketone breathalysers

Breath Test: The Acetone Indicator

A key to understanding breath testing is to understand how ketones are metabolised in the body. As mentioned earlier, breath meters test breath acetone, the ketone expelled through your lungs. The breathalyser measures this in something referred to as parts per million. Acetone production is a by-product of the fat metabolism process and is formed from the first ketone body produced by the liver, Acetoacetate. Acetone molecules are tiny and can be expelled or exhaled in the breath. The monitor has a little sensor that measures these ketone molecules and it is highly accurate.

Test Ketones
Ketone Monitor - Ketoscan Mini Review | Lean Fit Keto

The breathalyser test is an instant indication of whether you are more ketotic (deeper in ketosis) or becoming less ketotic (as foods or other aspects, e.g. exercising affects your level of ketones).

Real-time data

Another huge pro for me is the app’s function for collecting and storing your data. To be able to track the data and see a trend and moving average makes it easy to know when you need to boost your ketosis. There is also a section where you can add comments and add up to three photos of whatever data you want to collect. You can export your data using a simple email or sharing a jpeg image.

You can also set up notifications directly on the app in the settings to be reminded for when you want to do tests.


Believe it or not, the breathalyser monitor is inexpensive in the long run. Compared to blood ketone monitor strips, the per-test cost is significantly cheaper. Take a look at the comparison below.

 Blood Ketone Monitor

 Ketoscan Mini Monitor


Cost of machine with 25 strips equals R47,96 for 25 tests.Cost of machine with 300 breath tests equals R6,66 per test.
Cost of strips after first purchase: R499/25 strips equals R19,96 per test.Cost of new sensor @ R800 with 300 tests per sensor equals R2,66 per test

Although the initial costs of the Ketoscan Mini seem exuberant compared to the blood ketone monitor, which only costs R1199 and includes 25 strips, you have to think long term. Many people will even purchase cheaper blood monitor units but forget to consider the cost per strip going forward. The cost per strip is quite high as you can see in the table above almost R20. At R20 a test, you’ll probably only want to test once or twice a day, and that is not the best way to be tracking your ketones if you are tracking for a specific purpose.

Even if you were testing with the breathalyser 6 times a day, it wouldn’t cost as much as one strip of the ketone test strips.

The cost of the monitor is not the issue. The cost of continuous use of the strips is what adds up over time.


From when I opened the box, I was impressed with everything. Having tested two other monitors, I had a pretty good reference of what other monitors are out there, and there was just NO comparison to the Ketoscan Mini.

The Ketoscan Mini boxing and packaging gave me the impression of Apple product’s minimalistic and clean design. From the white box to the individually sealed mouthpieces etc. the product is really well packaged and contains the following items:

  • Individual foil pouch for the Monitor
  • Pouch to store your Monitor in
  • Actual Monitor
  • USB Power supply
  • Quick startup guide and user manual
  • Additional mouthpieces


Paring the monitor with the App

The first thing you’d want to do with your Ketoscan Mini is to pair it with your phone. The app is available in the app store for Apple and Android. The user manual and startup guide is very user-friendly and takes you through the setup quite easily.

How to use the device efficiently:

One thing I do want to caution on is learning how to blow into the Monitor. As a natural or automatic action, one tends to inhale just before you have to blow out. Try it for a second. Imagine you are going to blow into something and then see what your body does. You inhale, right! 

Ketone Monitor

It does take a little practice, in the beginning, to learn how to blow into the Monitor correctly and not have this automatic response to blowing out. It is important to learn how to blow out correctly because the highest concentration of Acetone is at the bottom of your lungs.

How to measure and when to measure:

Many people ask me what the best time to test ketones is. I would say you need to use the device to see what works for you. You could test every hour for a full day and track what you are eating.

The Ketoscan Mini is quite user-friendly and warns on your app of things that could influence your readings. As you can see in the image below, it is best to test at least 30 minutes after eating, brushing your teeth or eating or even smoking. Drinking alcohol can also affect the breathalyser, and it is advised to not test within 24 hours of consuming alcohol.

Here are a few things to keep in mind when you test ketones:

  • Morning ketones will be low because of your circadian rhythm. Glucose and cortisol are higher in the morning because it is a time when we should be waking up and be alert.
  • Measure when you are exercising before and after your workouts. Measure different types of workouts. Strength or weight training compared to cardio and see what your ketones do.
  • Keep in mind that your indication of a reading of 4, 6 or 9 ppm will be different than the next person’s reading. Our bodies are unique, and you need to use the data you collect over time and determine your own lifestyle.

Real-Time Fat Burning Monitor

So far, there has only been positive aspects of the Ketoscan Mini Breathalyser, and it probably seems that I am biased, but this is my honest review and experience using the Monitor. So, to continue the positive review, here are some more things I like about it.

When measuring your breath for ketones, you instantly know how much fat is being used as fuel. The Ketoscan Mini has a little gauge that indicates the rate at which you are burning fat and estimates the grams of fat burned per hour. That’s pretty neat. Many people (women) are totally obsessed with the scale; however, the scale is a very lagging (and inaccurate) measure of whatever you’ve been eating. Blowing into the breathalyser, for me, is a real-time indication of how the foods I have eaten affects my ketone levels. 

Test Ketones
Test Ketones

In other words, you can instantaneously see what your body’s fat-burning response is to what you are having to eat. 

Individual breath acetone readings do provide an indication of your immediate acetone levels, but collecting data and seeing a trend is where you want to get to. Which brings me to the last benefit, which I find great for my clients. 

Collecting the data of each breath automatically, I can have insights into your data. How much fat you are burning. How deep in ketosis you are. What have you eaten and how it is affecting your ketone levels.

Having your data is a wonderful way to adjust and make dietary improvements or adjustments to get optimal results from your diet.

Some of my personal findings:

Just to explain how using the monitor can give you better direction in the daily food choices you make. With my very first breath test on the monitor, I have been fasting for about 22 or 24 hours. It was just before 12pm when I met up with the gentleman from Ketoscan at a coffee shop and wasn’t expecting them to give me a Monitor or to ask me to test it. I’ve only had two cups of black coffee for the morning, which btw is an average day for me. When I did my first breath test, it was at level 10, which is relatively high. @impressive

As I experimented with the monitor, my readings increased and correlated with the hours I fasted. The longer I fasted, the more my ketones would increase.

Another finding was when I exercised. Strength training affects the production and use of ketones too. When I tested my ketones just after a weight training session, my ketones went down. An hour or two later, they would go up again. This makes sense to me because when you are sedentary and not using energy, the ketones build up in your body.

The value of the breathalyser is priceless if you start experimenting with different foods you are eating. You can directly see what foods affect your Acetone.

For example, I can drink black coffee with butter, and my ketones increase an hour later but drinking coffee with cream decreases my ketones slightly.

There are a lot of other things I have come to realize in terms of what I eat and do and how it affects my ketones.

Other applications for using the Ketoscan Mini to test ketones

Children with Epilepsy

I haven’t really looked into it, but I think that children can also use the meter as well. This would be great for children with epilepsy. You could easily, in a very non-invasive manner, test and have real-time readings on their ketone levels whereas I don’t even think pricking a child’s finger to take a blood reading is something that you’d want to be doing several times a day.

Ketone Breath Testing for Cancer

I am not going to go into depth here, but here is a fantastic video by a lady by the name of Alison Garnet who used a ketone breathalyser to help monitor her ketone levels and manage a very aggressive brain tumour.


  1. Several studies are showing how breath ketones correlate with fat burning. In one study done by Kundu et al. they evaluated 58 participants. A BrAce (breath acetone) reading of 2,1ppm corresponded with a fat loss of 227g per week.
  2. In another study with 12 participants following a calorie-restricted diet of 1200 calories per day on high fat, low carb diet. The group on the high fat, low carb diet lost more weight than the control group (4.4 vs 2.6). The high fat, low carb group’s BrAce was three times greater than the blood acetone levels of the control group with BrAce levels of 9 compared to 3.9ppm.
  3. Another study on Japanese subjects following calories (slightly higher than BMR) controlled intake with light exercise. A BrAce of 1.8ppm correlated with an average of 60g of fat loss per week over the 14-day trial.

Review of breath ketones paper published.

Conclusion of this paper published on testing breath ketones:

Endogenous breath acetone is correlated with and can be used to understand the rate of fat loss in healthy subjects. Maintaining a 2 ppm BrAce while on a calorie restriction diet should cause a fat loss rate of ∼227 g week−1. Acetone is correlated with fat loss because it and two other ketone bodies are the by-products of fat metabolism. Breath acetone is strongly correlated with the blood ketone body BOHB. Breath acetone can range in concentration from 1 ppm in healthy non‐dieting subjects to 1,250 ppm in diabetic ketoacidosis. In healthy individuals, breath acetone is affected by multiple factors. Dietary macronutrient composition has the greatest impact followed, in rank order, by caloric restriction, exercise, pulmonary factors, and other factors. Because of its relationship to fat metabolism, a high‐fat, low‐carbohydrate diet will generate more breath acetone than a standard mixed diet. A reduction in consumed calories relative to that needed for weight maintenance can increase breath acetone and fat loss. Exercise can promote caloric restriction.

Additionally, exercise can cause breath acetone elevation during a workout. Human respiratory factors can affect the acetone concentration in the breath sample. Other foods (e.g., garlic), drugs (e.g., disulfiram), and environmental conditions can increase breath acetone due to their ability to increase fat metabolism or block acetone metabolism. While the relationship between breath acetone and fat loss is well established, additional research is needed to understand these factors better and advance this area of integrative physiology.

If you have made it to the bottom of my post, thank you for sticking with me. I have tried to be comprehensive in my review and hope that you have found value in it deciding whether using a breath monitor is the right option for you. As you can see, I am impressed and convinced that it is a great tool with which you can get better results from your efforts. 


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