How to Use Keto Strips to Measure Ketosis

The ketogenic, or simply keto, eating plan is a low-carbohydrate, high-fat and moderate-protein regimen.

It offers numerous health advantages, such as weight reduction, improved blood sugar regulation and potential longevity benefits.

A frequent aim for those on a ketogenic plan is to reach ketosis, a natural metabolic condition in which the body burns fat for fuel.

However, it’s not always easy to know if your eating habits need adjustment to enter and sustain ketosis.

For this reason, many people rely on keto strips.

This piece outlines how to use keto strips to assess ketosis and how to achieve this state through a ketogenic diet.

What occurs during ketosis?

On a conventional high-carbohydrate diet, your cells primarily use glucose for energy, which comes from carbohydrate-rich foods including sugars and starchy items like bread, pasta and certain vegetables.

But if you restrict or avoid these foods — as is typical on a keto diet — your body lacks sufficient glucose to meet its energy requirements. It must therefore find alternative energy sources.

Your body responds by breaking down stored fat into fatty acids and ketone bodies. These ketones substitute for glucose and provide much of the energy your brain requires, producing a metabolic state called dietary ketosis.

Being in dietary ketosis raises ketone levels, which can be detected in breath, urine and blood.

Summary

When you significantly limit carbohydrates, your body generates ketones from fat, creating the metabolic condition known as ketosis.

Measuring ketosis with urine

If you want to confirm whether you’re in ketosis, urine strips are an inexpensive and convenient method.

They were initially developed for people with type 1 diabetes to check for immediate risk of diabetic ketoacidosis, a potentially dangerous condition.

You can buy urine strip kits over the counter at pharmacies and supermarkets, as well as online. They’re relatively cheap and come in packages ranging from about 50 to several hundred strips.

Keep in mind that strips generally expire three to six months after opening, so consider how frequently you plan to use them.

To track urine ketones day-to-day, test at a consistent time — for example, in the morning or a few hours after your last meal — for the best comparisons.

The steps for using keto strips are as follows:

• Wash your hands, then collect a urine sample in a small container.
• Dip the absorbent end of the strip into the sample for a few seconds, then remove it.
• Allow the strip to sit for the time specified on the package for the color change to occur.
• Match the strip’s color to the chart on the packaging.
• Dispose of the urine and strip appropriately and wash your hands afterward.

The color indicates the concentration of ketones in your urine, ranging from none to high. Darker colors reflect higher ketone concentrations.

Summary

Urine strips provide a simple and convenient way to detect ketosis. Follow the kit instructions for the most reliable outcome.

Measuring ketosis with blood

Blood ketone meters are a dependable and precise way to quantify ketones in your body.

Originally intended for people with type 1 diabetes, they are also favored by those on a ketogenic diet as a more accurate method of measuring ketosis.

Blood ketone strips can usually be purchased wherever urine strips are sold. However, you’ll need a meter to read the blood strips.

Many blood glucose meters are also compatible with blood ketone strips, though glucose and ketone strips are different products.

Blood strips cost roughly $1 per strip on average and typically remain usable for 12–18 months before expiring — considerably longer than urine strips (, 12).

How a blood ketone meter works:

• Wash your hands.
• Prepare the lancet with the needle according to the instructions.
• Insert a blood ketone strip into the meter.
• Use the lancet to prick your finger and obtain a small drop of blood.
• Touch the strip to the blood drop and read the result.
• Dispose of the strip and lancet as directed.

A preferred blood ketone range for dietary ketosis is 0.5–3 mmol/L (9–54 mcg/dl).

Summary

Testing blood ketones is more precise but also costlier than urine testing.

How accurate are keto strips?

Urine strips are a useful indicator of ketosis during the initial weeks of starting keto.

At this stage, your body is less efficient at using ketones for energy, so you excrete a large proportion of them in urine.

Over time, as you become more keto-adapted, your body improves at utilizing ketones for fuel and optimizes their production, leaving fewer unused ketones to be excreted.

In practical terms, if you’ve been keto-adapted for months, a urine strip might show only trace or no ketones, which could wrongly suggest you’re no longer in ketosis.

Still, urine strips are an easy and affordable way to confirm rising ketone levels when you’re beginning a ketogenic diet.

If you’ve been on keto for several months and want a clearer measure of ketone concentration, blood ketone strips are a better choice.

Bear in mind the higher cost of blood testing and the need to prick your finger each time you measure ketones.

Summary

Urine keto strips can indicate whether you’re in ketosis, especially early on, but may be less reliable long-term. Blood strips give a more accurate measurement.

How to achieve ketosis with a keto diet

For most healthy people, it takes several days on a ketogenic diet to enter ketosis and a few more weeks to become fully keto-adapted.

A keto diet is characterized by high fat, moderate protein and very low carbohydrate intake.

Some people confuse keto with a low-carb, high-protein approach. However, consuming excessive protein can prevent your body from reaching ketosis.

Typically, the diet comprises 65–90% of calories from fat, 10–30% from protein and under 5% from carbohydrates.

By contrast, the 2020–2025 Dietary Guidelines for Americans recommend that people consume:

• 20–35% of calories from fat
• 10–35% of calories from protein
• 45–65% of calories from carbohydrates

Generally, eating fewer than 50 grams of carbs per day will induce ketosis. Individual requirements vary — some people may need to consume less, while others can tolerate more.

If you’re new to keto and want to verify your dietary progress, urine strips can be a helpful tool.

Summary

A ketogenic diet emphasizes high fat, low carbohydrate and moderate protein. It takes several days to enter ketosis and several weeks to adapt to using ketones as a primary fuel.

The bottom line

Ketone strips are increasingly popular for people on a ketogenic diet who want to check whether they’re in ketosis.

There are two main types of strips: urine and blood.

Urine strips are suitable for beginners seeking an easy, low-cost way to confirm they’re progressing toward ketosis.

After you become keto-adapted, blood strips provide a more accurate assessment, though they are pricier.

Either method can help you monitor and tweak your diet to achieve and maintain ketosis.