How long does it take to get into ketosis?

If you’ve been eating sugar for most of your life and decide to switch to the ketogenic diet, chances are that you’re going to need at least a month, even up to six weeks to get into ketosis by just following the keto diet, according to Dr. Eric Berg.

Many people think this process is faster, but switching to a new fuel source takes some getting used to. According to Dr. Berg, some people can get into ketosis within a week if they’re healthy and speed up the process by cutting sugar to zero, or adding certain ketone supplements to the diet.

Everyone’s body is different. How soon one can get into ketosis can vary even if two people are using the same methods and approach. How soon ketosis occurs and the number of ketones in the blood varies from person to person and depends on several factors such as percentage of body fat, as well as resting metabolic rate — the energy needed to maintain basic bodily functions.

Can I Speed Up My Transition To Ketosis?

When it comes to implementing a new lifestyle, you shouldn’t hurry. To get into ketosis, you’ll just have to follow the ketogenic macronutrient plan, which consists of:

  • 70-80 percent fat
  • 20-25 percent protein
  • 5-10 percent carbohydrates

Ketosis switches your body from burning mainly glucose to burning mainly ketones for energy. Even though it’s best to be patient, follow macros and wait for the ketosis to kick in, some people still want fast results. In the following paragraphs, you can learn a few ways that can help you reach ketosis faster and more efficiently.

Reduce your carb intake

To get into ketosis, you’ll have to cut down carbs and consume more foods rich in fat. Let’s say that an average person should consume 2,000 calories per day, which equates to a maximum of 50 grams of carbohydrates per day. Even though this is far less than the average person consumes on daily basis, it’s still high if you want ketosis to kick in as soon as possible. Most people will go a lot lower than 50 grams per day to reach ketosis fast.

Consume protein at moderate level

If you’re determined to reach ketosis fast, you shouldn’t be eating more than 20 grams of protein per day. Many people decrease their protein intake because it can turn into glucose in the bloodstream through the process of gluconeogenesis.

You shouldn’t be worrying about this if you’re just starting the keto diet; just stick to the recommended percentages of macros for a while and track your progress by taking tests, which will be discussed further in this article.

Exercise more

Being physically active, especially doing high intensity exercises such as running or lifting weights can help you get into ketosis. Exercise depletes the body of its glycogen stores. When you limit your carb intake, your glycogen stores stay low, so your liver will start producing ketones – an additional fuel source for your muscles. Research has found that the level of ketones increases for a few hours after physical activity has ended.

Take exogenous ketones

Unlike endogenous ketones that are made by the liver when following the ketogenic diet or during intermittent fasting, exogenous ketones have to be ingested in the form of a dietary supplement. They are able to get you into ketosis without changing your eating habits.

Consuming exogenous ketones will never trigger natural production of ketones and can’t put you body in a ketogenic state, which can only be achieved by the natural production of ketones.

According to studies, drinks with exogenous ketones are able to increase blood ketone concentrations and they imitate the ketogenic diet without the need to change your eating habits. This is why their popularity is growing rapidly.

Take C8 MCT oil

Many keto dieters turn to medium-chain triglyceride (MCT) oil – the type of fat most commonly derived from coconut oil – to boost energy and speed up the production of ketones. Caprylic or octanoic acid (C8) can be a beneficial supplement to boost your energy levels and speed up ketosis.

Practice intermittent fasting

A person can get into ketosis through intermittent fasting. In fact, this is a popular method among many keto dieters because it can get you into ketosis in just a couple of days. When you fast, your body is depleted of glycogen quickly and as a natural reaction, it starts producing ketones.

According to studies, intermittent fasting can help you lose extra fat, as well as preserve muscles during the weight-loss journey. But if your goal is to fight a disease or to get some related benefits of ketosis, it would be best to try to get into ketosis the usual way — with the help of a plain keto diet.

How To Know You’re In Ketosis?

The best way is to know if you’re in ketosis is testing. There are three measurable ketone bodies and three common ways of measuring them:

  • Beta-hydroxybutyrate (BHB) – Best measured in the blood
  • Acetoacetate – Best measured in the urine
  • Acetone – Best measured in the breath

Blood monitors — Testing your blood with a ketone meter is the most precise method to learn about your ketone levels. If beta-hydroxybutyrate level ranges anywhere between 0.5 and 3.0 mM, it means you’re definitely in a nutritional ketosis. This test requires pricking your finger regularly so it can be unappealing to some people, but there are other methods if you’re bothered by finger-pricking. Another downside is that these tests can be more expensive than other ketone-testing methods.

Ketone test strips — Also known as urine strips, keto strips are thin paper strips able to detect the level of ketones in urine. They’re affordable and easily detect acetoacetate and acetone, which are a certain sign of ketosis, but unfortunately they can’t detect BHB – the most accurate indicator of ketosis. Urine strips only show the excess ketones that our body couldn’t use. This number might be small, but the number of ketones in our blood can be a lot bigger. Nevertheless, the strips are quick and give results within a minute. When you want to know your level of ketones, you just have to urinate on a keto strip and wait for a while. The kit comes with a color chart so you can simply match the color of your stick to the chart and that’s the number of your ketones. Hydration may affect urine strip results as well. If someone is drinking unreasonably large amounts of water, it might dilute the urine and the test will show lower concentrations of ketones. Also, if someone is seriously dehydrated, they might have higher concentrations of ketones in the urine.

Breathalyzers — Breathalyzers are devices that estimate ketone content from a breath sample. When your body is burning fat, acetone is produced and expelled through breath. While breathalyzers can be useful for those new to the ketogenic diet, they’re less reliable than blood tests. They come in a wide range of prices, and some cheaper versions can still be effective. Ketonix is perhaps the best breathalyzer on the market, specifically made for people who follow the keto diet. It’s approved by the FDA and offers acetone reading in parts per million, but it’s extremely expensive, with the latest version currently selling for 239 USD.

Symptoms of ketosis

Keto breath

After a certain period of following a keto diet plan – once full ketosis is reached – people tend to develop a characteristic fruity breath that is often referred to as unpleasant. This is due to increased level of acetone, a type of ketone that is expelled through breath and urine.


Because ketosis makes you burn fat as a source of energy, it’s a viable tool for weight-loss. A randomized control study from 2017 tested the effects of the keto diet in combination with Crossfit. Researchers found that people following the keto diet decreased their weight and overall body fat in only 6 weeks, unlike those in the control group.

Reduced appetite

Feeling less tempted to eat whatever you find around the house is one of the first symptoms that ketosis might be kicking in. Those following the diet have reported feeling full and satisfied for a longer time. Apparently, high levels of ketones may have an appetite-suppressant effect.

Digestive issues

Following a high-fat diet that is low in carbs (thus low in fiber as well) can lead to stomach troubles. A study done on mice suggests that bacteria eat the colon lining when depleted for fiber.

If you’ve been following the ketogenic diet for some time, you know that common side effect of reaching ketosis are constipation and diarrhea. To treat constipation and other belly aches, you can try adding some fiber through low-carb keto plant foods and supplements. Drinking water and staying well-hydrated also helps with constipation.


Another common side-effect of the keto diet is temporary insomnia, which can last anywhere from a few days to a month. Poor sleep is most pronounced in the initial stage of going towards ketosis. Many ketoers reported bad sleep during the night when they first drastically cut their carbs. Poor sleep and insomnia are common symptoms during the initial stages of ketosis.

In conclusion

Different people need different time to get into ketosis. For some, it can happen 48 hours after going extremely low carb, and some people may not even have to go below 100 grams of carbs per day to achieve the same, especially if the person is highly active.

There are ways to speed up this process, but you don’t want anything too abrupt. Fasting from time to time can help you achieve ketosis, as well as taking exogenous ketones, or C8 MCT oil.  Combining some of these solutions probably works like magic!

Just remember: Reaching ketosis once doesn’t mean you’ll remain there. Going back to carbohydrates as a main food also means going back to glucose as the main energy source instead of ketones. To get back into ketosis, you should follow the same approach that helped you reach it for the first time.

1 thought on “How long does it take to get into ketosis?”

  1. Please fact check your article. It’s says you don’t want to get more than 20g of protein per day. That is incorrect. You only want the macro ratio of protein at 20-25% (like you stated previously in your article) and not 20 grams.


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