Keto Strips: How Long Do They Work?

Ketone test strips are a popular way to measure whether someone is in ketosis—a natural metabolic state where the body burns fat for fuel. Typically, people following a ketogenic diet use these strips to ensure they are in ketosis and, therefore, burning fat optimally. The strips are made from a special type of paper that changes colour when it comes into contact with ketones in the urine. The darker the colour, the higher the ketone levels. However, ketone strips are not always accurate, and factors such as hydration levels can affect the concentration of ketones in the urine. Additionally, as the body adapts to a ketogenic diet and becomes more efficient at creating ketones, the strips may show a lighter colour even though the person is still in ketosis.

How to use keto strips

• Wash your hands and, if you are a man, wipe the tip of your penis with a disposable cleaning cloth. If you are a woman, open your labia and clean from front to back.
• Urinate into a small container or directly onto the strip. If using a container, ensure you collect a "clean-catch" sample by holding the collection cup in the urine stream. You will need an ounce or two of urine in the cup.
• Dip the absorptive/reactive end of the keto strip into the urine sample for a few seconds. Alternatively, place the end of the testing strip directly into your urine flow.
• Remove the strip from the urine and wait 15 seconds to one minute. The amount of time you need to wait may vary depending on the brand of keto strips you are using, so always check the packaging.
• Compare the colour of the strip to the colour chart on the bottle or packaging. The colour depth change indicates the concentration of ketones in your urine. Light pink means ketones are present but in small amounts, while dark purple means you are in full-blown ketosis.
• Dispose of the urine and strip appropriately and then wash your hands.

Some additional tips for using keto strips:

• Test at the same time each day for the best comparison, such as in the morning or several hours after your last meal.
• Check the expiration date on your test strips and do not use them if they are expired.
• Protect the test strips from damage and keep them in a cool, dry place away from direct sunlight and heat.
• Do not touch the test area of the strip or allow it to touch any surfaces.
• Only use strips that have not discoloured.

It is important to note that keto strips are not always accurate, especially if you have been following a keto diet for several months. This is because your body adapts to using ketones for fuel, so fewer ketones will be found in your urine. If you want a more accurate reading, consider using blood keto strips or a ketone breathalyser.

How long do keto strips last?

Keto strips are used to check the level of ketones in the urine, which can indicate whether a person is in ketosis. They are typically used by diabetes patients and those looking to lose weight.

Keto strips will generally last for 30 to 90 days after being opened. This is because, once opened, they are exposed to the air and will begin to expire. The speed at which they expire depends on the inventory rotation and the time of purchase. Storing them in a humid location, such as a bathroom, will also make them expire faster.

Most keto strips have an expiration date of around two years after their manufacturing date, but this only refers to an unopened bottle. Once opened, keto strips will usually expire within three to six months.

You can tell that your test strips have expired as they will simply stop working. No matter how keto your diet has been, the strips will show zero ketones.

To make your keto strips last longer, keep the lid on tight and store them outside of humid environments.

What do keto strip colours mean?

The colours on keto test strips correspond to the concentration of ketones in your urine, which can range from no ketones to high concentrations. The darker the colour, the higher your ketone levels.

Ketone test strips work by detecting the amount of ketones in your urine—specifically, the ketone body acetoacetate. The strips have a small pad at one end that you place in your urine stream. The pad contains a chemical that will detect ketones and change colour depending on the concentration of the ketones in your urine.

Every manufacturer is a little different, but typically, the fewer ketones you have, the lighter the colour will be on the test strip. Similarly, the more concentrated your urine is with ketones, the darker the test strip will be. Most colour schemes range from light pink on one end to dark purple on the other (indicating progressively higher ketone levels).

• Negative (no ketones): You are not in ketosis at all.
• Trace (0.5 mmol/L): This means light nutritional ketosis.
• Small (1.5 mmol/L): This means light nutritional ketosis.
• Moderate (4.0 mmol/L): Ketones increase further as a result of exercise or fasting.
• Large (8.0 mmol/L): Usually a result of prolonged fasting, not sustainable in the long term.
• Larger (16 mmol/L): Usually a result of prolonged fasting, not sustainable in the long term.

The optimum level for ketosis falls between 0.5 and 2 mmol/L. However, higher ketone levels aren't necessarily better for everyone. While high ketone levels (5 mmol/L and above) can lead to more significant weight loss, this may eventually result in nutrient deprivation and a loss of muscle mass.

It's important to note that urine keto strips can be inaccurate and may show false negatives. As you get deeper into ketosis and become keto-adapted, your body will begin to efficiently convert acetoacetate and produce more of the ketone beta-hydroxybutyrate (BHB), which cannot be detected using urine test strips.

If you want a more accurate reading of your ketone levels, blood keto strips or a breath ketone testing device are better options.

How to get into ketosis

Ketosis is a natural metabolic state in which the body primarily burns stored fat for fuel instead of glucose. This occurs when there is a lack of glucose, which is the body's main source of energy. The body can also use ketones for energy, but they may leave the body via urine.

• Reduce Carbohydrate Intake: Ketosis occurs when a lack of carbohydrates forces the body to use fat, not glucose, as its primary energy source. It is recommended to reduce carb consumption to 50 grams or less per day, but this may vary from person to person.
• Increase Physical Activity: The more energy you use during the day, the more fuel your body needs. Exercise helps deplete the body's stores of glycogen (a form of glucose). Eating carbs usually restores glycogen levels, but on a low-carb diet, these stores are not sufficiently replenished, encouraging the body to turn to fat as fuel.
• Fasting for Short Periods: Intermittent fasting can help a person reach a state of ketosis. Short fasts of 24-48 hours may be recommended by a doctor, but most people do not need to fast this long to reach ketosis.
• Increase Healthy Fat Intake: Most people aiming for ketosis replace lost carbohydrates with an increase in healthy fats. Sources of healthy fats include avocados, avocado oil, and fatty fish such as salmon. It is generally advisable to limit saturated and trans fats, such as those from fried foods.
• Test Ketone Levels: Testing ketone levels can help a person track their progress and make adjustments to their diet. Simple ketone tests, such as strips and monitors, are available to purchase online.
• Check Protein Intake: While recommended amounts vary, a standard recommendation is to consume about 1 gram of protein per pound of body weight per day. People who exercise heavily may need up to 1.5 grams per pound.
• Consume More MCT Oil: Medium-chain triglycerides (MCTs), which can be purchased as oil, may help a person reach ketosis even when eating less fat and more protein and carbs than a typical keto diet.

The time it takes to enter ketosis varies from person to person and depends on factors such as dietary plans and activity levels. For most people, it usually takes a few days to enter ketosis, but for some, it may take a week or longer.

Symptoms of Ketosis:

As your body transitions into ketosis, you may experience symptoms such as headaches, fatigue, nausea, bad breath, and increased thirst, sometimes known as the "keto flu."

Testing Ketone Levels:

Testing your body's ketone levels is the best way to know if you are in ketosis. There are three types of ketones: acetoacetate, acetone, and beta-hydroxybutyrate, which can be measured through your urine, breath, and blood, respectively.

Tips to Achieve Ketosis:

• Eat 20-50 grams of carbs per day.
• Track your carb intake to ensure you are within the recommended range.
• Limit eating out at restaurants, as it can be harder to track your carb intake.
• Be aware of hidden carb sources, such as condiments and sauces.
• Increase your intake of high-quality fats, aiming for 55-60% of your calories from healthy fats.
• Try intermittent fasting to help your body shift its fuel source from carbs to fat.
• Exercise more to deplete your body's glycogen stores and encourage ketone production.
• Test your ketone levels regularly to adjust your diet accordingly.

Precautions:

Before starting the keto diet, it is important to consult a healthcare professional. The keto diet is not suitable for everyone, and there are potential risks and downsides associated with it. Long-term health complications may include fat buildup in the liver, kidney stones, inadequate protein levels, and vitamin deficiency. Additionally, adhering to the strict limits of the keto diet can be challenging and unsustainable for many people.

How to maintain ketosis

Maintaining ketosis requires a strict low-carb diet, regular exercise, and possibly fasting or supplements. Here are some detailed tips on how to stay in ketosis:

Diet

• Lower your carb intake: Limit your carb consumption to between 20-50 grams per day. Avoid high-carb vegetables like peas and squash, starchy foods like corn and potatoes, and grains like wheat, rice, and oats.
• Eat more healthy fats: Focus on meat like beef, chicken, and even bacon, high-fat vegetables like avocados, full-fat dairy products, and products that contain coconut oil.
• Get adequate protein: For the average healthy adult, protein should account for 30-35% of total dietary calories on keto. However, older adults, those looking to grow muscle, and people recovering from injuries may need more. Excessive protein intake can prevent ketosis, so it's important to find the right balance.

Exercise

• Create a regular exercise schedule: Aim to exercise at least 3 times a week for half an hour or more. Running or power walking for half an hour a day will help you stay in ketosis.
• Exercise more when you consume carbs: If you eat more carbs on a given day, increase your exercise to burn them off and stay in ketosis. Consider only eating carb-heavy meals before a workout.

Fasting and Supplements

• Intermittent fasting: Try skipping a meal or stretching times between meals. For example, skip breakfast every day or try to fit all your eating into an 8-hour window during the day.
• Fat fasting: On a fat fast, you eat only a small number of high-fat calories in a day. For example, you could eat several cuts of beef in a day, paired with green vegetables.
• Supplements: Supplements like omega-3 fatty acids, electrolytes, digestive enzymes, exogenous ketone supplements, and medium-chain triglycerides (MCTs) can boost ketosis.

Testing and Professional Consultation

• Test your blood: Use a ketone meter to measure your blood ketone levels every day or a few times a week to ensure you're in the optimal range for ketosis (0.5-3.0 mmol/L).
• Consult professionals: Talk to your physician, a fitness trainer, and a dietitian or nutritionist before starting a ketogenic diet. They can provide insight into the safety of the diet for you and help create a plan to meet your goals.

Frequently asked questions