Testing Yourself for Ketones

Back when you were going crazy with the carbs, your body had no reason to burn all that stored fat. The large amounts of carbs you were eating kept you stocked full of glucose and glycogen (which are made from carbohydrates you eat) and that was what fueled you. Now that you’re on the Ketogenic diet, you’ll need to test yourself for ketones. The biggest reason is to make sure you are in ketosis, which basically means that your body is actively burning bodily and dietary fat for fuel. That is the main goal of the Keto diet and the whole reason it is so great for weight loss. If you’re just starting the diet, you’re going to want to know when you first get into ketosis. If you’ve been eating high fat low carb for a while, you’re going to want to know how deep into ketosis you are. Whatever the case, monitoring your ketones is smart and can help you get to know your body better. It will let you know if you are straying from the path or staying on the right track.There are three ways to test yourself for ketones. The two most common ways are to test your urine or test your blood. The third way is to test your breath. There are advantages and disadvantages to each method and I’ll cover them in the following paragraphs. One thing to keep in mind is that there are 3 types of ketones each detectable in a different way.
Acetoacetate is excreted in your urine and measured by testing your urine.

Beta-hydroxybutyrate is excreted in your urine and measured by testing your blood. These ketones are associated with nutritional ketosis.

Acetone is excreted in your breath and measured by testing your breath.

Ketone Test Strips

Using ketone test strips is probably the most common way people test for ketones. They’re cheap and sold at many drug stores and department stores with pharmacies. They aren’t the most accurate method of testing and they only measure acetoacetate, but they do have their uses. Ketone test strips are easy to use because all you have to do is pass one through your urine stream or pee in a cup and dip one in. The ketone test strips are good for people who are new to Keto and need to know when they’ve gotten into ketosis. They’ll also suffice for those who have been in ketosis for about a month or less. After a month, most people become keto adapted and the test strips give a lot of false negatives. This happens because when you become keto adapted the acetoacetate you produce gets broken down into beta-hydroxybutyrate in larger quantities. This results in reduced amounts of acetoacetate excreted in your urine. Another result is frustration and confusion.

Imagine this scenario. You’ve been doing everything right in regard to your eating habits and testing yourself daily using the ketone test strips with positive results. Then one day you get a negative reading. You say to yourself maybe it was a bad strip or something and wait a while until you have to pee again to retest. You get another negative. Every test after that is negative. You begin to think about what you’re doing wrong but can’t figure it out, and then discouragement sets in. That’s exactly what happened to me and I was pretty close to quitting. There weren’t as many informational resources back then so it was harder to figure what was going on. Eventually I figured out that I was still in ketosis and there was nothing wrong with what I was doing. It was the test strips.

Blood Test

Another way of testing yourself for ketones is by testing your blood. It’s the most accurate method because it measures the ketones that are circulating in your blood now, not what is being excreted. This makes for the most accurate snapshot of what is going on in your blood stream as far as ketone production goes. The process of testing your blood for ketones is essentially the same process diabetics go through when testing for glucose. Other than the meter you need and the strips you use, the equipment you use is the same as what a diabetic uses. To test your blood for ketones you’ll need the meter, some strips, lancets, a lancing device, and alcohol pads. When it comes to testing for ketones, this is my preferred method. It works for everyone who is concerned with their blood ketone levels and is accurate.

Testing your blood for ketones is a bit of a process to be honest. For proper instructions you should read the manuals that come with the meter, but here’s the steps in a nutshell. First you prepare the lancet and lancing device. Then you insert a strip into the meter. The third step is to wipe down the finger your going to prick to get the blood sample with an alcohol pad. The fourth step is to prick your finger and put the blood on the proper area of the strip that you inserted in the monitor. A few seconds after that you’ll get your reading.

The blood ketone meter I have is the Abbot Precision Xtra meter. The great thing about this meter is its ability to test for ketones and glucose. If you’re diabetic or would like to know both your blood ketone and glucose levels you will only need one meter (but two different strips) if you get the Abbot Precision Xtra. When I purchased my meter I got it from Amazon in a bundle that comes with the meter, 10 Precision ketone strips, 100 lancets, 100 alcohol pads, and a lancing device.

Breath Test

As mentioned earlier, acetone is a type of ketone excreted from your breath and is responsible for the Keto breath that people have. Ketone breath testers take a reading of the amount of acetone in your breath. All you have to do is breathe into it, similar to a regular breathalyzer test, and it gives you your result. The breath testers are certainly easy to use. There are a few things to be aware of when using them, though. The strength of your exhale can affect the readings. You have to be consistent when you exhale into the machine or your results will be all over the place. If you blow too hard, your results will be inflated. If you blow into it again with less intensity, your result will be lower. Even though internally your ketone levels may be consistent. More and more people are beginning to use ketone breath testers because of their ease of use and because you don’t need to continuously purchase things. Ketonox makes a ketone breath tester that is reusable. You only need to purchase it once and you can use it over and over again.

Ketone breath testers are sort of a new technology. When something is new, there are usually some kinks that need to be ironed out. Even still, this method is much better than using the urine test strips to test for ketones.


Before I end this post I want to leave you with a few key points about each method and how they compare to each other.

Ketone Test Strips

Pros: very inexpensive, easy to get, simple to use

Cons: only good for those who are newly in ketosis (about 1 month or less), inaccurate for those who have been in ketosis longer than a month

Blood Test

Pros: very accurate, gives info about ketones in your blood stream now

Cons: expensive, requires recurring purchases (strips, alcohol pads, lancets)

Breath Test

Pros: Very simple to use, reusable (in the case of Ketonix tester), accurate

Cons: inconsistent results due to variation in strength of breath, requires recurring purchases (in the case of disposable tests)

Ok, So…

Which way is the best way?

My answer is testing your blood. The main reason is accuracy. Why go through the trouble of testing if the information you’re getting is not accurate? Secondly, is consistency. With the breath tests you have a level of human error involved (too hard or too soft of a breath)and the urine strips are basically useless after a while. With the blood testing set up the strips cut down on inconsistencies and human error. If you don’t get enough blood in the strip it won’t read, meaning you can’t under do it, and the strips can only take in so much blood, meaning you can’t over do it.

Two factors I didn’t consider in my answer are cost and the fact that you have to prick yourself for the blood test. I understand that those two factors could prevent someone from using the blood testing method. If that applies to you then you should look into using breath testers.