The Different Types of Ketone Testing

by Brooklin White MS, RDN, LDNLifestyle
Ketone meter, lancet, and ketone strips on a table

Ketone Bodies and Ketosis

Ketosis is considered a metabolic state where fat provides most of the fuel for the body. Ketone bodies, such as beta-hydroxybutyrate, acetoacetate, and acetone, are produced from fat stores in the liver when glucose supplies are limited. There has been extensive research on the benefits mild ketosis has on the brain. Beta-hydroxybutyrate for instance, increases the production of Brain-Derived Neurotrophic Factor (BDNF) which is a crucial neuron and synapse supporting molecule (1). Permitting ketone bodies to supply a portion of the body's required energy compensates for the deficiency in glucose (carbohydrate) metabolism that is seen in Alzheimer’s patients (2). Reduced glucose uptake by the brain due to the downregulation of a certain glucose transporter (GLUT1) and increased insulin resistance has been strongly associated with the progression of cognitive decline (3)(4). Incorporating a partial ketogenic diet could alleviate the effects of this impaired glucose metabolism by providing ketones as alternative substrates for the brain to use as energy (5). Maintaining mild ketosis therefore, is a crucial aspect of the Bredesen Protocol and thus learning how to measure your ketone levels is just as important.

What are the types of ketone tests?

There are three types of ketone tests, those that measure beta-hydroxybutyrate levels in your blood, those that measure acetone levels from your breath, and those that measure acetoacetate levels in your urine. As mentioned above, all are produced when in a state of ketosis, however, some tests are more reliable than others.

Blood Ketone Testing:

Blood ketone testing can be measured at home with a single prick of the finger. Once a drop of blood is placed on the end of a ketone strip, it is inserted into the meter for a ketone reading. The goal for those on the Bredesen Protocol is to keep beta hydroxybutyrate from 0.5 mmol/L to 4 mmol/L as it indicates your body is in a state of mild ketosis (6).


    • The most accurate indicator of mild ketosis.
    • Measures beta-hydroxybutyrate which is readily transported to cells as fuel (1).
    • Results are given quickly.
    • Recommended by Dr. Dale Bredesen.


    • Requires a finger prick.
    • Ketone strips can be expensive.

Urine Ketone Testing:

Urine strips work by dipping the ketone strip into a urine sample for a few seconds and then comparing the color of the strip with the colors given on the package. The darker the color, the more ketones are present in your urine.


    • Quick results.
    • Easy to administer.


    • It is the most unreliable source of testing.
    • The results are based on colors rather than a specific reference range.
    • The ketones measured by the urine strip are a measurement of ketone excess in the body and are not an accurate measurement of the level of ketones in your blood that are used as fuel by the brain.
    • Results may be impacted by hydration levels.
    • Strips are only good for about 30 days from the day they are opened.

Breath Ketone Testing:

Since acetone is such a small particle, it seeps into the lungs and can be measured by a simple breath test (7). The breath test works just as it sounds – by breathing into the monitor to determine the level of acetone present in your breath.


    • Quick results.
    • Easy to administer.


    • Low accuracy as acetone is not a measure of ketones found in the blood that are used as fuel by the brain.
    • External factors, such as mints, gum, sugar substitutes, tobacco, lip balm, toothpaste, coffee, alcohol, prescription drugs etc., can impact the level of acetone and can cause meters to fail (7).
    • Acetone levels can vary depending on your activity level (if you are breathing heavily, you are more likely to expel higher amounts of acetone).
    • Consistent calibration is required (8).

When to measure ketones?

Testing ketones at roughly the same time each day is important for tracking your ketosis state (9). When first beginning the KetoFlex diet, it's beneficial to test more often so that you can make the connection between how you feel and your state of ketosis. We recommend testing once before each meal to understand where you are in ketosis and determine if any meal adjustments should be made. For example, you can test once in the morning before breakfast and while in a fasting state, once before lunch and once before dinner. After you have adopted the KetoFlex diet for several months and have a better understanding of what ketosis feels like, you may just need to test periodically.

What's the Takeaway?

Since beta-hydroxybutyrate is the main ketone your body utilizes during ketosis, it is the most important ketone to measure. The blood meter, therefore, is the gold standard for measuring your level of ketosis.

Our recommendations: Our favorite blood ketone meter is the Keto-Mojo (you can receive a 15% discount off of ketone meter kits using this link).


  1. Henderson, S. T. (2008). Ketone bodies as a therapeutic for Alzheimer’s disease. Neurotherapeutics,5(3), 470–480.
  2. Hertz, L., Chen, Y., & Waagepetersen, H. S. (2015). Effects of ketone bodies in Alzheimer’s disease in relation to neural hypometabolism, β-amyloid toxicity, and astrocyte function.Journal of Neurochemistry,134(1), 7–20.
  3. Koppel, S. J., & Swerdlow, R. H. (2018). Neuroketotherapeutics: A Modern Review of a Century-Old Therapy.Neurochemistry International,117, 114–125.
  4. De la Monte, S. M. (2017). Insulin Resistance and Neurodegeneration: Progress Towards the Development of New Therapeutics for Alzheimer’s Disease.Drugs,77(1), 47–65.
  5. Broom, G. M., Shaw, I. C., & Rucklidge, J. J. (2019). The ketogenic diet as a potential treatment and prevention strategy for Alzheimer’s disease.Nutrition,60, 118–121.
  6. Bredesen, D. (2017).The end of Alzheimer's: The first program to prevent and reverse cognitive decline. Penguin.
  7. Anderson, J. C. (2015). Measuring breath acetone for monitoring fat loss: Review.Obesity,23(12), 2327–2334.
  8. Testing: When to test your ketones & glucose. (2020, January 28). KETO-MOJO.
  9. Testing for ketosis: Difference between blood, breath, urine. (2020, June 12). KETO-MOJO.