Keto Test Strips: How Do They Work?

Ketone test strips are used to measure the level of ketones in your urine or blood. Ketones are produced when your body doesn't have enough insulin to turn sugar into energy, so it uses fat instead. This process is called ketosis, and it can be dangerous for people with diabetes, as it can lead to a condition called diabetic ketoacidosis (DKA). DKA is a medical emergency that can be life-threatening. For this reason, people with diabetes may need to regularly test their ketone levels. Testing can be done through urine or blood samples, with blood tests being more accurate but also more expensive. Urine test strips are a cheap and convenient way to test for ketones, and they can be purchased over the counter at pharmacies and supermarkets.

How to use keto test strips

Keto test strips are used to measure the level of ketones in your urine or blood. This is known as ketosis, a natural metabolic state that your body enters when following a very low-carb diet or during starvation.

Using Urine Strips

Urine strips are a cheap and convenient way to test for ketosis. They are ideal if you're new to the keto diet and want an easy and affordable way to ensure you're headed towards ketosis.

• Wash your hands and clean your genital area. If you're a man, wipe the tip of your penis with a disposable cleaning cloth. If you're a woman, open your labia and use the cloth to clean from front to back.
• Collect a urine sample in a clean container. You can do this by holding the collection cup in the urine stream until you've collected an ounce or two.
• Hold the absorptive end of the strip in the urine sample for a few seconds.
• Remove the strip from the urine and shake off any excess liquid.
• Wait for the amount of time outlined on the package for the strip to change colour. This is usually around 15 seconds.
• Compare the colour of the strip with the colour chart on the packaging. The darker the colour, the higher your ketone levels.
• Dispose of the urine and strip appropriately and wash your hands.

Using Blood Strips

Blood strips are a more accurate but also more expensive way to measure ketosis. They are more suitable if you've been following a ketogenic diet for several months and want a precise picture of your ketone levels.

• Wash and dry your hands.
• Insert a blood ketone test strip into the meter, following the directions provided.
• Prick your finger with the lancet to draw a small drop of blood.
• Let the strip come into contact with the drop of blood.
• Check the results on the meter.
• Dispose of the strip and lancet as instructed.

Tips for Using Keto Test Strips

• For best results, test your urine at a specific time of day, such as in the morning or several hours after your last meal.
• To keep results accurate and reliable, collect a clean-catch urine sample and replace the cap of the strips after each use.
• Do not expose the strips to sunlight, moisture, or heat.
• Check the expiration date before testing and do not use the strips if they are discoloured.
• If you have type 1 diabetes, always have a supply of urine keto test strips and know how to use them.
• If you have concerns about your ketone levels or other symptoms, consult your doctor.

When to test for ketones

• If you have diabetes: Clinical recommendations suggest testing for ketones when blood sugars are elevated or when someone with diabetes is ill. This is so that early intervention can reduce the risk of diabetic ketoacidosis (DKA), a dangerous and potentially life-threatening condition. If you have type 1 diabetes, you should always have a supply of ketone test strips and know how to use them. If you have type 2 diabetes, consult your doctor or nurse about when to test for ketones.
• If you are pregnant: Consult your doctor or nurse about when to test your urine for ketones. If you have type 1 diabetes and are pregnant, the Association of Diabetes Care and Education Specialists advises checking for ketones when blood sugars are greater than 200 mg/dL.
• If you are on a keto diet: Urine strips are ideal if you are new to the keto diet and want an easy and affordable way to ensure you are entering ketosis. Once your body has adapted to the keto diet, blood strips are more accurate but also more expensive.
• If you are experiencing symptoms of DKA: These include fruity-smelling breath, dry mouth or dehydration, and nausea, vomiting, or stomach pain. If you are experiencing any of these symptoms, test for ketones and seek medical advice if necessary.
• If your blood sugar is high: Many experts advise checking for ketones when your blood glucose is more than 240 mg/dL, while others suggest checking when it is more than 300 mg/dL. If you use insulin pump therapy, test for ketones when blood sugars are greater than 300 mg/dL with no apparent cause or if your blood sugar has not decreased two hours after a correction dose of insulin.
• If you are ill or stressed: If you have diabetes, test your ketone levels every 4 to 6 hours if you are ill. If you are feeling stressed, test your ketone levels, as this could be a sign of high blood sugar.
• If you are on your period: If you have diabetes, test your ketone levels when you are on your period.
• If you are unable to eat: If you have diabetes and have been unable to eat, test your ketone levels.
• If your insulin pump stops working: If you have diabetes and your insulin pump stops working, test your ketone levels.

It is important to consult your healthcare professional about when and how you should test for ketones, as the ideal testing schedule may vary depending on your individual circumstances, age, specific situation, and medication regimen.

Interpreting keto test strip results

Keto test strips are used to measure the level of ketones in your urine. This can indicate whether your body is in a state of ketosis, which is a natural metabolic state where your body burns fat for fuel. The strips have colour codes that indicate the level of ketones in your urine—the darker the colour, the higher your ketone levels.

Interpreting the results of a keto test strip involves comparing the colour of the strip to the colour chart provided with the test kit. This will give you a range of how many ketones are in your urine. If the strip takes on any colour other than the original beige, it's an indication that there are some ketones in your urine.

• Negative (no ketones): You are not in ketosis.
• Trace (0.5 mmol/L): Light nutritional ketosis.
• Small (1.5 mmol/L): Light nutritional ketosis.
• Moderate (4.0 mmol/L): Increased ketone levels as a result of exercise or fasting.
• Large (8.0 mmol/L): Usually as a result of prolonged fasting; not sustainable in the long term.
• Larger (16 mmol/L): Usually as a result of prolonged fasting; not sustainable in the long term.

It's important to note that urine testing for ketones may not always be accurate, especially if you've been in a keto-adapted state for many months. In this case, a keto strip may indicate only trace amounts of ketones, if any, even though you are still in ketosis. Blood ketone testing is generally considered to be more accurate.

Additionally, the best time to test your urine for ketones is in the early morning or several hours after dinner, as these times provide the most reliable results.

Accuracy of keto test strips

Keto test strips are a popular tool for measuring ketosis, but they are not always 100% accurate. The accuracy of the readings may fluctuate for several reasons.

Keto test strips are small strips of special paper that change colour when they come into contact with ketones in the urine. The strips have colour codes that indicate the level of ketones present, with darker colours indicating higher ketone levels.

Limitations of Keto Test Strips

• Ketones in Urine Do Not Reflect Overall Ketone Levels: Ketones that are unused by the body are excreted in the urine. Urine strips only measure these unused or excess ketones. Therefore, a small number of ketones in the urine does not necessarily mean that the levels in the blood are also small, or that the body is not in ketosis.
• Hydration Levels: While hydration levels may not significantly affect readings for most people, extreme dehydration or over-hydration may impact the accuracy of keto test strips.
• Adaptation to Ketosis: When the body first enters ketosis, it may not be using ketones efficiently for energy, resulting in a higher concentration of waste ketones in the urine. As the body adapts to burning fat for fuel, it becomes more adept at burning ketones for energy, leading to a decrease in ketone readings over time.

Alternative Methods for Measuring Ketosis

Although keto test strips are a reasonably accurate and inexpensive way to detect ketosis, there are more accurate but more expensive methods available:

• Blood Ketone Meters: These measure beta-hydroxybutyrate, the most prevalent and stable ketone body in the blood. Blood ketone testing is considered the gold standard for measuring ketosis as it provides a direct measurement of ketone levels in the blood.
• Breath Ketone Analyzers: These measure acetone, a byproduct of the breakdown of acetoacetate, one of the main ketone bodies. While breath analyzers are not as accurate as blood meters, they are a one-time purchase and can be reused as often as needed.

Where to buy keto test strips

If you're looking to buy keto test strips, there are a few options available to you. You can purchase them over the counter at your local pharmacy or supermarket, or you can buy them online.

Pharmacy and Supermarket

Urine strip kits are readily available at pharmacies and supermarkets, and they are relatively inexpensive. These kits typically contain anywhere from 50 to several hundred strips and will expire within three to six months of opening.

Online

If you prefer to shop online, there are a variety of retailers that offer keto test strips. Amazon, for example, has a wide range of options, including:

• Perfect Keto Ketone Test Strips: These strips are designed for testing ketones in urine on a low-carb ketogenic diet. The kit includes 100 precision test strips and is easy to use at home or on the go.
• Nurse Hatty Ketone Test Strips: This option includes 150 test strips with a built-in color chart, a free keto guide eBook, and a free app. The strips are extra-long and made in the USA.
• Keto-Mojo Ketone Test Strips: This product offers 150 test strips with a free keto guide eBook and a free app. The strips are extra-long and ensure easy and accurate testing.

Other online retailers may also offer keto test strips, so it is worth exploring different websites to find the best option for your needs.

Blood Strips

In addition to urine strips, you can also find blood strips at places that carry urine strips. Blood strips are more expensive, typically costing around $1 per strip, but they offer a more accurate measurement of ketone levels. Keep in mind that you will also need a meter to read the blood strips.

Whether you choose to purchase keto test strips from a pharmacy, supermarket, or online retailer, always follow the directions for testing and disposal, and be sure to check the expiration date before use.

Frequently asked questions