How Long Does the Keto Flu Last? | Keto Flu Remedies

So, you’ve just started this wonderful ketogenic diet and now you are feeling miserable. What happened. It is probably what is commonly known as the “keto flu.” I know, you didn’t sign up for this. How long does the keto flu last? Well, that is going to depend on a number of factors. It really is individual and will be based on how quickly your body is removing toxins. It is the process of cleansing and changing over to burning fats as a fuel source that is making you feel like crap.

It is somewhat tough to answer this question as it varies from person to person. Generally, most people find the keto flu symptoms are the worst in the first week of eliminating the carbohydrates from their diet. For some, the symptoms of the keto flu will linger into the second and a few people report experiencing the keto flu lasting from three to five weeks.

What is the Keto Flu?

The keto flu is a natural reaction that your body has when you switch from burning glucose as energy to burning fat instead. As your body switches, it can feel like you are withdrawing from an addictive substance. This withdrawal period can leave you feeling dizzy, achy, nauseous, and experiencing muscle cramps.

Fat is actually your body’s preferred fuel source, even though it is the secondary fuel source that it uses. Glucose, or sugars, is used up quickly by the body. When glucose is used up, the body begins to rely on fat. As your body begins to burn fat as fuel instead of carbohydrates, you enter a metabolic state known as ketosis.
The keto flu occurs as the body is adapting to fat burning or ketosis. Keto flu is the result of becoming keto-adapted, electrolyte loss and dehydration and withdrawal from carbohydrates and sugary foods.

The process of keto-adaptation means getting the body used to the process of beta-oxidation, which is converting fat into energy. Most people are in a state of glycolysis, or converting glucose into energy. Getting into beta-oxidation is easier for some people than others due to metabolic flexibility, which refers to how well a person can adapt to using different fuel sources. Genetics and your current level of health will determine how metabolically flexible you are.[easyazon_image align=”right” cart=”n” height=”500″ identifier=”1986236129″ locale=”US” src=”” tag=”mcurle08-20″ width=”333″]

Most diets contain a huge amount of processed foods, which are high in added sugars and salts. As you switch to a keto diet of whole foods, the salt-laden choices are eliminated and sodium intake is drastically reduced.

Sodium causes the body to retain water. Therefore, less sodium intake means that you have less water retention. The lack of carbohydrates also lowers. This leads the kidneys to release excess water. As the excess water is released, electrolytes are flushed out. This creates an electrolyte imbalance and dehydration. Until everything becomes balanced, you may experience flu-like symptoms.

Finally, you are dealing with carbohydrate withdrawal. Research shows that sugar impacts the brain in a way that is similar to heroin or cocaine. While it is pleasurable, we get a nice shot of dopamine when eating sugar. This gives us a good feeling.

As sugar is drastically reduced when you start the keto diet, you will experience withdrawal effects such as mood swings, irritability, cravings for sugar and other flu-like symptoms.




When Does the Keto Flu Start?

People typically experience flu-like symptoms from the keto flu as their bodies are transitioning from glucose burning to fat burning. The keto flu starts within the first few days of implementing the diet. The first few days of a ketogenic diet, you will notice an increase in cravings for carbohydrates. These cravings typically subside after the first couple of days. However, you may still feel drowsiness, headaches, brain fog, difficulty getting to sleep, some nausea may occur as well as stomach irritability. These symptoms show up usually within the first week of start of your diet as you are adjusting. The keto flu tends to subside the longer that you are on the ketogenic diet and following it consistently.


Symptoms of the Keto Flu

As your body adjusts to the ketogenic diet, you may experience some following symptoms. These may be mild or intense. You may have some or all of them depending on how metabolically flexible your body is when you start the ketogenic diet. If your body is very metabolically flexible, it will quickly and easily adjust to burning fats for fuel instead of glucose. If it isn’t, you will feel some following symptoms.

  • Carbohydrate cravings
  • Brain Fog
  • Irritability
  • Poor concentration
  • Stomach aches
  • Dizziness
  • Confusion
  • Muscle soreness
  • Difficulty falling asleep
  • Sore throat


Soothing The Keto Flu Sore Throat

One thing that has people concerned is what to do about the keto flu sore throat that shows up. You don’t want to down a lozenge that is coated in sugar. That moves you out of ketosis. However, you do want relief from the sore throat.[easyazon_infoblock align=”right” cart=”n” identifier=”B01B510T8A” locale=”US” tag=”mcurle08-20″]

  • Drink hot water – this will soothe the throat
  • Drink some chicken stock or bone broth – the heat will soothe the throat. It will provide you with vitamins and minerals. Rather than going for the carb-loaded chicken noodle soup (or store bought chicken broth, which can be high in MSG and other additives), give bone broth a try to help alleviate your symptoms. Bone broth is an easy way to sneak more water into your diet and it also provides electrolytes, such as sodium and potassium.
  • Try some electrolytes – pickle juice anyone?

How to Beat the Keto Flu

There are some things that you can do to minimize the keto flu symptoms and beat the keto flu.

  • Get moving – promotes good digestion and circulation of the body. Go for a walk, take a hike or a gentle jog. Don’t overexert yourself as you are adjusting to your new diet, but make sure that you are incorporating movement throughout your day. This can also can actually help relieve muscle pain and tension and release endorphins which will help boost your mood and motivation.
  • Stay hydrated – you will feel more flu like symptoms when your body is dehydrated. A well hydrated body functions better and the channels of elimination work properly. Staying hydrated will help relieve headaches and boost your energy levels when you’re feeling sluggish.

If you don’t know how much water you need, follow this simple equation. Divide your current body weight (in pounds) by two. The result is the number of ounces you should be drinking per day. For example, if you weight 150 pounds, you’ll need at least 75 ounces of water per day to stay hydrated.

  • Exogenous ketones can help! You can try taking an exogenous ketone supplement, such as Perfect Keto to reduce the keto flu symptoms. Exogenous ketones fight fatigue and boost energy levels by raising the ketone levels in your blood. Keep in mind, exogenous ketones are not meant to replace the ketogenic diet, but simply supplement it![easyazon_infoblock align=”right” cart=”n” identifier=”B076PT9MT8″ locale=”US” tag=”mcurle08-20″]
  • Start weaning yourself off of carbohydrates before you officially start the ketogenic diet. You will notice fewer cravings as your body adjusts if it is done slowly.
  • Increase your salt: The average American diet is overloaded with processed foods. As you eliminate the processed foods, the salt that was causing water retention in your body suddenly isn’t there and you are flushing out the excess water. Taking some salt can help to hold onto some water. Five grams of salt per day is ideal to counter the keto flu and replenish electrolytes.


The symptoms of the keto flu are uncomfortable, but going through it is worth it. Your body will begin to heal and function much better. Most people experience weight loss after that initial period. They also discover more energy, less bloating and fewer digestive issues.

However, the diet only works if you stick with it. If the symptoms seem unbearable, try to add a few more “clean” carbohydrates to your diet. Add some extra vegetables and fruits and then slowly reduce your carbohydrate load so that the keto flu symptoms aren’t so unbearable.

What happens if you give up or cheat on your diet? Don’t worry about it. Just pick back up the next day. Adjusting will be easier the second time around. Keep in mind that this is a journey towards better health!