The 16 Most Common KETO Side Effects and Remedies

author avatar Dr. Eric Berg 08/31/2023

Hey guys, in this article I'm going to cover some of the most common keto side effects and remedies. Maybe you feel like you've got the "keto flu," or maybe you just don't feel 100%. Well, you're in the right place.

There are a number of reasons why a keto diet could be causing adverse side effects. After all, a keto diet switches your body from burning sugar for energy to burning fat. This is a process that your body is not used to. You have to allow your body some time to acclimate to your new diet.

When you first switch up your diet, you may become deficient in certain nutrients. Often times, this happens when you aren't eating a wide range of keto-friendly foods. If you jumped into keto too quickly, your body won't have time to get used to these changes and this can give you a bad case of the keto flu.

Before we talk about the most common keto side effects and remedies, I'm going to cover the basics of the keto diet and ketosis, so you better-understand these keto flu side effects.

A man with a painful abdominal cramp |  The 16 Most Common KETO Side Effects and Remedies

What is keto?

Keto is short for ketogenic. The keto diet is a very-low-carbohydrate and high-fat diet. This causes your body to burn fat as your fuel source instead of sugar—going into what is called ketosis. Ketosis is a metabolic state, which is characterized by elevated levels of ketones.

A keto diet can help with all sorts of physical and mental conditions. It can help with weight loss, brain fog, regulating blood pressure levels, and much more.

The problem is that it can also cause something called the keto flu. The keto flu is just a term used to describe the symptoms that can experience when you first start doing keto—keep in mind that not everyone experiences them.

The keto flu is often caused by an imbalanced diet, jumping in too quickly, or insufficient nutrients. Some forget that you can't only consume fats. Going on a sugar and carbohydrate restriction is a great start, but you need a well-rounded diet with plenty of healthy vegetables when on a ketogenic diet. Vitamins and minerals are key to a healthy body.

Once you've fixed these problems and your body is keto-adapted, these keto flu symptoms go away, and you go back to feeling good again. Let's take a look at the 16 most common keto side effects and remedies and how to avoid all keto side effects easily.

1. Muscle Cramps

Have you experienced muscle cramps more frequently since you've been on a ketogenic diet? This is a common keto side effect that many people struggle with. They don't always happen while exerting your body or moving in an unusual position. They can happen while you're sitting still or even sleeping. But don't worry. This is a straightforward problem to solve. Most often, muscle cramp symptoms are due to a lack of potassium.

If you think about it, those that aren't on a ketogenic diet often eat high-carb or high-sugar foods like potatoes, bananas, oranges, and yogurt. These foods provide a large amount of potassium. However, they aren't keto-friendly foods. They contain enough sugar and carbs to kick your body out of ketosis.

Thankfully, there are a huge variety of potassium sources you can choose from while still watching your carbohydrate intake. Avocado, salmon, edamame, cremini mushrooms, nuts, spinach, and other leafy green veggies are low-carb options that are high in potassium.

Get plenty of these keto-friendly potassium sources in your diet, and these cramps should go away quickly.


A potassium deficiency caused by a lack of potassium-rich foods.


Up your potassium intake by eating keto-friendly foods that are rich in potassium—avocado, nuts, spinach, etc..

2. Palpitations/Heart Arrhythmias

Heart palpitations are very common, but they can be scary when you feel them. They give you a sensation that your heart is skipping a beat, fluttering, racing, or pounding. Most of the time, it’s not a sign of a severe problem such as heart disease—but always get them checked out if they persist.

Going on a ketogenic diet can cause heart palpitations. This is likely because your body is low on potassium. One way that your body becomes deficient in potassium on a keto diet is that as you lose your glycogen reserve, you also lose a lot of water that contains electrolytes. Potassium is one of your body's most important electrolytes.

The flow of potassium in and out of your heart's cells plays an instrumental role in regulating your heartbeat. So when your body doesn't have enough potassium, your heart can beat irregularly, also known as palpitating.

The simple solution is to up your potassium intake. As I mentioned before, there are many ketogenic-friendly sources of potassium.


Low levels of potassium which causes an irregular heartbeat.


Up your potassium intake with potassium-rich ketogenic foods.

3. Weakness

Weakness is a common symptom of keto flu. One of the mechanisms of a keto or low-carb diet is a reduction in Fat Storing Hormone levels. Fat Storing Hormone has many functions in the body, including telling your kidneys when to retain sodium.

When you go on a keto diet, your Fat Storing Hormone levels reduce, and your body begins to shed the excess sodium and water that your body has retained.

This process can be a good thing, but if you don't replenish some of the sodium your body gets rid of, you can start feeling weak and even lightheaded. Sodium is an essential electrolyte, and your body needs plenty of it to function properly.

The easiest way to replenish sodium—and in turn, regain your strength—is to add some sea salt to your food. Give that a few days, and you should be feeling better. Just stay away from sports drinks that advertise that they are electrolyte replenishing.

They contain way too much sugar. Instead, have some bone broth since it can provide a significant amount of sodium.


Not getting enough sodium.


Simply add extra sea salt to your meals for a few days.

4. Bad Breath

Some people experience bad breath while on a ketogenic or low-carbohydrate diet. This is also known as "keto breath." Why does this happen, and how can you fix it? The problem usually starts with consuming too much protein. While small amounts of protein are essential when doing keto, too much isn't good, and it can cause keto breath.

As protein breaks down in the digestive system, your body produces ammonia, which is then expelled through urine and exhalation. Exhaling ammonia can cause some serious bad breath issues. What can you do to fix this? Eat less protein and get more fat through things like nuts, olive oil, and avocados. If cutting back on protein doesn't help, also try consuming some apple cider vinegar for digestion.


Consuming too much protein.


Cut back on protein and increase healthy fats.

Blurry photo of women feeling dizzy |  The 16 Most Common KETO Side Effects and Remedies

5. Dizziness

Another symptom of keto flu is dizziness. This may be a dizzy feeling as if you just got spun around in a chair, or it can even just feel like heavy brain fog. This is most often a problem of low sodium and dehydration, which come hand in hand. Sodium helps your body retain water. The best remedy for keto side effect is to add some sea salt to your food and drink some water.


An electrolyte imbalance caused by low sodium.


Add sea salt to your food and drink plenty of water.

6. Fatigue

Fatigue is a very common flu-like symptom that often comes in the first week of the keto flu. Now, this is a short-term problem that is easy to take care of if you know what the issue is. Most often, the problem is not getting enough vitamin B1 and vitamin B5. The best way to get these vitamins is to use nutritional yeast.

Give that a try.


Low levels of B1 and B5 vitamins.


Add nutritional yeast to your food.

7. Feeling Cold

Have you found yourself feeling cold more often within the first few weeks of starting keto? This could be another keto flu symptom. More often than not, this is caused by low iodine levels. Feeling cold is a common symptom of iodine deficiency. Thankfully, there are some easy remedies for this. You can try using high-quality sea kelp. Sea kelp is rich in iodine as well as many other vitamins and minerals.


Low levels of iodine.


Take high-quality organic sea kelp.

8. Not Satisfied After Eating

If you're on a low-carb diet or a keto diet and you still feel hungry after eating a meal, you need to eat more fat. When your body adapts to ketosis, and you actually start healing Fat Storing Hormone resistance, the need for fat goes down because your body is running on your own fat. But, when you're first starting out, you won't feel as satisfied. The solution is to increase the fat. You can also try having some apple cider vinegar. Apple cider vinegar will help reduce your appetite and make you feel full for longer. This can also help a lot with weight loss.


Not enough fat intake.


Get more healthy fat in your diet and try suppressing hunger with apple cider vinegar.

9. Right Shoulder Pain

In contrast with the last keto flu symptom, if you go on a keto diet and consume way too much fat or way too many nuts, you may experience right shoulder pain. Too much fat can irritate the gall bladder. There's a nerve in the gall bladder that goes straight to the right shoulder. This can also radiate to the right side of your neck or head and cause neck pain or a headache. The remedy is to cut back on your fat consumption.


Consuming more fat than you need.


Cut back on fat and nuts.

10. Constipation

Constipation is a common side effect of the keto flu. This can happen because of two reasons. First, you may be consuming way too much meat and cheese. In this case, you should start gradually increasing your vegetable intake. The second problem is consuming way too many vegetables that your body isn't used to. In that case, cut down on the vegetables until your body is used to them, and increase your intake of fermented foods.

Any significant change to your diet can cause constipation. Try to keep a well-rounded diet rather than consuming too much of one thing.


Too much meat and cheese OR too many vegetables.


Look back on what you changed just before you became constipated. If you started eating more meat and cheese, balance it out with more non-starchy vegetables. If started eating too many vegetables, increase your intake of fermented foods.

11. Lower Back/Abdominal Pain

If lower back pain or abdominal pain starts after several weeks of being on a ketogenic diet, you may have developed a small kidney stone. Low-carb diets are notorious for contributing to these stones since most people also increase their protein intake. Too much protein can cause stones.

The remedy is to increase your potassium level. You can take a potassium citrate electrolyte powder with lots of water. In combination with increasing your potassium, you should also have a lot more citrus. Add a generous serving of lemon juice to your water and consume that regularly.


A kidney stone.


Increase your potassium intake and drink plenty of lemon juice.

12. Vivid Dreams

If vivid dreams happen more often while on a low-carb or ketogenic diet, you're likely low on vitamin B1. You can get B1 by having some nutritional yeast or eating sunflower seeds. Nutritional yeast is a great way to get a long-term supply of B1 without taking supplements. Plus, it tastes great on food.


Not getting enough vitamin B1.


Increase vitamin B1 intake with nutritional yeast or sunflower seeds.

13. Bloating

Bloating while on a low-carb or ketogenic diet is a problem that can happen when having too much fat. Most often, if you still feel hungry on a ketogenic diet, you tend to consume too more and more fat. Cut back on your fat intake and start having more apple cider vinegar. Apple cider vinegar will help you stay full longer as well as reduce bloating by aiding the digestive system. As I mentioned before, apple cider vinegar can help with weight loss, which will naturally reduce bloating.


Consuming too much fat.


Reduce fat intake and have more apple cider vinegar to curb cravings and aid digestion.

14. Rash

Having a rash while on the ketogenic diet can happen because of two reasons. One reason is that you're not getting enough B vitamins. In this case, use more nutritional yeast. The other reason you may be that your liver is dumping toxins, which means you need to consume more fresh vegetables.


Low in B vitamins OR your liver is dumping toxins.


Use nutritional yeast and add more vegetables to your diet.

A woman grabbing her head because of a painful headache |  The 16 Most Common KETO Side Effects and Remedies

15. Headaches

Having frequent headaches while on a ketogenic diet means that you're jumping in too quickly. It's perfectly fine to start slow with your keto diet. You can slowly work towards reducing your carb intake and going sugar-free. The ketogenic diet is not a race. Trying to make it one will only contribute to keto flu symptoms most commonly the keto headache. Intermittent fasting too much too soon can cause blood sugar issues, which can lead to frequent headaches.


Jumping into the ketogenic diet and intermittent fasting too quickly.


Take your time and allow your body time to adjust to a keto diet.

16. Nervousness/Anxiety

The last keto flu symptom we're going to talk about is nervousness and anxiety. Most often, this is caused by not getting enough B vitamins—especially vitamin B1. Again, nutritional yeast is a great way to increase your B vitamins.


Insufficient levels of B vitamins.


Increase your B vitamin intake with nutritional yeast.

I hope you enjoyed this article. Give these 16 keto flu remedies a try and see how they help you.

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