Keto Urine Strips: Do They Expire And Stop Working?

Ketone test strips are used to measure the level of ketones in your urine when you're on a ketogenic diet. They are usually small strips with a coloured square that reacts with your urine to indicate the level of ketones. While they are a cheap and convenient way to test for ketones, they are not always accurate. Inaccurate results can occur due to factors such as hydration levels, kidney problems, and the body's adaptation to the ketogenic diet. As the body becomes more efficient at using ketones for fuel, fewer ketones will be excreted in the urine, making it difficult to detect ketosis with urine strips. This is why blood ketone meters and ketone breath analysers, though more expensive, are considered more accurate methods for measuring ketone levels.

How do keto urine strips work?

Ketone test strips are small urine testing strips that specifically test for ketones in your urine. The presence of ketones in the urine is the first sign of ketone production, which is why these strips are useful for those on a keto diet.

The strips are made from a special type of paper that contains chemicals that change colour when they come into contact with ketones in the urine. The strips have colour codes that indicate the level of ketones in your urine. The strips usually have a light beige colour, which gets darker as the level of ketones increases.

To use a keto testing strip, expose the coloured squares on the strip to your urine. You can do this by either dipping the stick in a container of urine or placing the end of the testing strip directly into your urine flow. After 40 seconds, the colour will change and you can use the colour chart provided to determine your reading.

It is recommended to test daily at first, but it is important to not get obsessed with the readings as it can take up to 4 days for the strips to show results. Your hydration and eating habits can impact your test results, so it is important to be consistent with your testing times and be aware of any changes to your activity levels, the day's humidity and temperature, and your drinking patterns within 12 hours of testing.

When should you use keto urine strips?

When starting out on a keto diet, testing strips are a great way to see if you are on the right track. It is recommended to test daily at first, shifting your focus from the scales to your ketone levels. You can test at different times of the day to see if you get different readings.

The best time to test is early in the morning on an empty stomach, as your body will have rested and cleared the food taken in before night, giving accurate results. You can also test at midday or before bed, but be aware that your hydration and eating habits can impact your test results. Being consistent with your testing times, as well as being aware of any changes to your activity levels, the day's humidity and temperature, and your drinking patterns within 12 hours of testing, is very important.

It is also important to note that urine strips are not always accurate. They only measure the unused or excessive ketones that your body doesn't use. Blood ketone levels are more accurate than urine strip tests.

How accurate are keto urine strips?

Ketone test strips are made from a type of paper that changes colour when it comes into contact with ketones in the urine. They are a non-invasive, quick, and easy way to measure ketones in the body.

However, ketone strips are not always accurate. They are most accurate when used early in a keto diet, as they can help determine whether your ketone levels are rising. After the body has adapted to the keto diet, fewer ketones will be found in bodily fluids, and so the strips may not be accurate.

To ensure the most accurate results, it is recommended to test in the morning or after a meal, maintain hydration, and be aware of any kidney problems.

There are two other ways to test for ketones: blood ketone meters and ketone breathalysers. Both are more expensive than urine test strips but are also more accurate. Blood ketone meters are the most expensive option, with the meter costing $50-$100 and the test strips also being costly. They detect beta-hydroxybutyrate, the most metabolically active ketone. Ketone breathalysers are cheaper but less accurate than blood ketone meters. They detect acetone in the breath, which studies show directly correlates with blood beta-hydroxybutyrate.

What are the pros and cons of keto urine strips?

The pros and cons of keto urine strips are as follows:

Pros:

• They are a cheap and convenient way to test for ketosis.
• They are non-invasive and provide results in seconds.
• They are easy to use and can be purchased over-the-counter at pharmacies and supermarkets, as well as online.
• They are ideal for people new to the keto diet who want to ensure they are on the right track.
• They can be useful for people with type 1 diabetes to monitor their condition and check for diabetic ketoacidosis, a potentially life-threatening condition.

Cons:

• They are not always accurate, especially for people who have been on the keto diet for a long time and are keto-adapted. In this case, blood keto strips are a more accurate option.
• They do not provide concrete numbers and are therefore a semi-quantitative measure of blood ketones.
• They can be influenced by external factors such as hydration, medication, and vitamins (especially vitamin C).
• They may not be suitable for testing ketosis achieved through exogenous ketone supplements as the rapid increase in blood ketone levels may not show up in urine tests.
• They have a short shelf life and typically expire within three to six months of opening.

What are the alternatives to keto urine strips?

Alternatives to Keto Urine Strips

Ketone urine strips are a cheap and convenient way to find out if you are in ketosis. However, they are not always accurate, especially for people who have been on the keto diet for a long time. So, what are the alternatives?

Ketone Blood Meters

Ketone blood meters are a more reliable and accurate way to measure ketones in your body. They were originally designed for people with type 1 diabetes but are also used by those following a ketogenic diet who want a more precise measurement.

You can usually find blood strips at any place that carries urine strips, but you will need a meter to read them. Many blood glucose readers can also read blood keto strips, even though the strips themselves are different.

Blood strips cost on average $1 per strip and typically last 12-18 months before expiring—much longer than urine strips, which expire within three to six months.

To use a blood ketone meter, you will need to prick your finger to draw a small drop of blood. This may be off-putting for some people.

Breath Testing

Breath testing is another alternative method for measuring ketones. There are now breath analysers available that can measure the level of acetone in your breath. The more acetone in your breath, the deeper you are in ketosis.

Measuring Ketones in Your Blood

If you want to measure ketones in your blood, you can use a blood ketone meter, as described above. However, this method is more expensive and requires you to prick your finger.

Testing at Specific Times

Urine strips are most accurate when used at specific times of day, such as first thing in the morning or several hours after your last meal. Testing at these times can help you get a more accurate picture of your ketone levels, without needing to switch to blood testing.

Tracking Other Signs of Ketosis

Aside from testing, there are other ways to tell if you are in ketosis. Signs that suggest you are in ketosis include fatigue, bad breath, dry mouth, weight loss, flu-like symptoms, and decreased hunger and thirst.

Consulting a Healthcare Professional

If you are unsure whether you are in ketosis, or if you are concerned about your ketone levels, the best course of action is to consult a healthcare professional. They can advise you on the best course of testing and treatment.

Frequently asked questions