Why does keto make me irritable?

It can take 3 to 6 weeks to adapt to a ketogenic diet. During that time irritability may occur from insufficient electrolyte supplementation (especially sodium), potentiation effects of existing medications causing side effects, or psychological factors related to making big lifestyle changes. You are not irritable because you are not eating carbohydrates. Your brain is supplied plenty of glucose endogenously through gluconeogenesis.


Sometimes I do keyword searches to try to figure out what to blog about. And I came across a snippet that was so misinformed and downright misleading my stomach sank. That this snippet came from a revered institution made it all the more egregious. I was so upset by the damage such a snippet could do, that I actually reported it to Google as misinformation.

Misinformation Snippet provided by Harvard Health

I am not arguing with you that you feel irritable. It is quite possible you are feeling irritable while transitioning to the ketogenic diet. There are a lot of reasons this may be happening.

But it is NOT because your brain is not getting enough glucose. I promise you. Your liver makes all the glucose your noggin may want or ever need, right on-demand, from a process called gluconeogenesis. This process is not stressful for the body or damaging in any way. Your liver happily does it for you.

So why might you be irritable on the ketogenic diet? Let’s go through the many reasons you may feel irritable on keto.

You are irritable on keto because you are taking medications that need to be adjusted or discontinued

As always, this is with the help of your prescriber. But if you are doing keto and you are feeling irritable, this could be because you are still taking medications that are being affected by the diet. These can be psychiatric medications, medications designed to lower blood sugar, or even medications that are supposed to help other conditions but that raise your blood sugar as a side effect.

Medications that lower blood glucose

If you are on ANY kind of medication designed to lower your blood sugars, and using those in addition to a ketogenic diet, you are likely becoming hypoglycemic. And this could be making you quite irritable (hangry). Sometimes we need to adjust medications very quickly on a ketogenic diet.

Medications that raise blood glucose

Some medications actually RAISE your blood sugar, all by themselves. Actually, a lot of them do. And so it is possible that one of your other medications, not designed to lower blood sugar, is potentially getting in the way of your keto-adaptation or causing you to go in and out of a ketogenic state. Popping in and out of a ketogenic state early on, makes you feel awful and as your energy goes up and down unnecessarily it can make you feel irritable.

Here is a resource that will help you figure out which medication may be messing with your blood sugar and you can ask your prescriber about whether it is ok to lower it or even temporarily discontinue it as you work towards your keto-adaptation.

Drugs That Can Affect Blood Glucose Levels

So check with your prescriber and ask about reducing your medications.

Psychiatric medication side effects

As someone who helps people transition to a ketogenic diet to treat mental illness, this is an area I watch carefully with clients and their prescribers. A ketogenic diet is a powerful therapy and it changes how your brain works. Because it makes your brain work better, the medications you usually take for psychiatric issues (SSRIs, mood stabilizers, anti-psychotics, etc.) can begin to cause side effects.

This is called potentiation, and it basically means that because your brain is working better, your current dose of the medications use to help yourself feel better is now too high. The easiest way to be on the lookout for potentiation effects is to look up the side effects of the medications you currently take. One of those side effects may very well be irritability. If you see that you are having these side effects, it may be your current dose and not the keto.

You are irritable on keto because you are not being diligent about supplementing your electrolytes

The best way to do this is to get a good quality sea salt (I like Redmond) and measure out 5-7g in a small dish and make sure that you have salted your food or taken in that amount by the end of the day. If you are using pink salt, you must double this, because it only contains about 40mg of sodium as opposed to sea salt which contains 90mg.

I cannot stress this enough! Your brain cannot work well without enough sodium. You literally have sodium-potassium pumps that make your brain (and other cells) work. If you feel poopy or irritable or even just a little off while on the ketogenic diet, your first go-to is always electrolytes.

Some people need more than this 5-7g guideline. For people who get migraines for example you may need 13g. Keep salting until you feel better. I have clients take a 1/4 tsp of salt every few hours and chase it down with some water. Often they feel better in about 20 minutes. If you are someone who wants or needs to have a flavor to drink water you can use a lower carb electrolyte drink and add a good 1/4 to 1/2 tsp of salt to it, or you can purchase LMNT, which has a good amount of salt already in it, as any good electrolyte drink should.

You also may be needing a lot more magnesium than you think. This is an important mineral for EVERYONE and just about everyone walking the planet is insufficient in this nutrient. So please, get a good magnesium glycinate supplement, and don’t be afraid to take it generously. Some of my clients do really well with 600-800mg of elemental magnesium in glycinate form. You can even supplement with a small amount of potassium, but usually, this is not necessary because the sodium helps your body protect and manage your potassium levels. But if you are feeling irritable, possibly from low electrolytes, a tiny bit of potassium is not a bad thing.

You are irritable on keto because you need to eat more

A lot of people do keto to lose weight, which is great but they cannot get out of the calorie restriction mindset. During the first 3 to 6 weeks, their body is figuring out how to switch fuel sources. It is learning to adapt by turning genes on and off, upregulating certain enzymes, and doing a whole lot of other impressive things. The body needs adequate energy to do that, and if you are still manifesting a deep down phobia of eating fat you are going to struggle. You are going to be hungry and irritable.

If you restrict energy too much then your body releases stress hormones. This can make you irritable. Don’t calorie restrict for those first 6 weeks. Just enjoy your ketogenic foods. Sometimes it takes our body a little while to get good at learning to unlock our fat stores, particularly if we have insulin resistance. And so in the meantime, it is ok to use dietary fat to fuel your body. Don’t worry.

You are irritable on keto because you need additional supports for the brain

As someone who helps people use ketogenic diets for psychiatric and neurological conditions, I know that this can be a real thing. Sometimes we add supplementation with medium-chain triglycerides (MCTs) that the liver immediately makes into ketones. Sometimes we add ketone salts. Both of these provide an immediate increase in ketones, that the brain can then use for fuel. This can help a brain struggling with psychiatric and/or neurological issues. It allows them to maintain energy in areas of the brain that are no longer using glucose well (hypometabolism). Psychiatric issues are often brain metabolism issues, and sometimes getting ketone levels up with MCT oil or ketone salts can really help.

You are irritable on keto because you have not adjusted emotionally to the change

It is also quite possible that you are feeling irritable on the ketogenic diet because of how you are experiencing it and how your change in what you eat interacts with your environment. As a mental health therapist, I can tell you that our thoughts about things drive our emotions. Any of the following could create automatic thoughts that make you feel irritable while on the ketogenic diet. Remember, anger is often a defense against feeling sadness. And so your irritability may be coming from feeling a sense of loss or even fear about how the diet will or might change your life and relationships.

You are mad or sad to do this diet in the first place

Many people do the ketogenic diet to reverse chronic diseases such as psychiatric, neurological, or other metabolic disorders like diabetes, high blood pressure, or even chronic pain conditions. All those pills and medications did not work or had side effects that made you feel even worse. And so now, here you are, having to implement a particular dietary therapy in order to try to feel well, while other people seem to be fine just eating all the carbohydrates all the time. It feels really unfair. And perhaps you have not radically accepted that you were sick and/or miserable enough to have to do this in the first place.

You don’t feel supported by your family or environment

Your spouse keeps bringing Oreos into the house or your children demand highly processed packaged foods. They demand that you make two types of meals each night, one low carb and one reflecting the standard American diet, which you cannot have anymore. You are having a hard time finding keto-friendly foods at the grocery store, or the processed keto foods most like what you used to eat are expensive and not even very keto.

Someone keeps bringing donuts to the office or having Birthday cake, and you cannot figure out how to go out to eat or be social with friends. And even when you do go out to be social, your friends keep trying to tempt you with higher carbohydrate choices or get moody and offended when you won’t eat what they brought.

This may be why you are irritable on keto. These are all situations that require an adjustment and for which you deserve support and help problem-solving. Feelings of sadness and anger, dare I say irritability, are understandable and valid emotions while learning how to be on a ketogenic diet.

You miss the flavors of certain foods

There are a lot of well-loved foods that you need to restrict on a ketogenic diet. You may miss the taste of banana in your morning smoothie. Sometimes you really want the taste of salted caramel. And you don’t know how to taste those things again and you just really miss it. Again, this is an example of where anger (or irritability, a lesser intense form of anger) is masking sadness and loss.

There is a learning curve with keto. You probably didn’t know that you could get banana extract and add it to your morning smoothie. Or that you can find salted caramel bars with a ketogenic recipe (like the one here).


There could be a lot of reasons you are feeling irritable on keto. And those should all be addressed. I want you to feel amazing. You deserve to feel amazing.

It might be a good idea to work with a keto diet coach or find a low-carb informed physician (see the resources page) to help you with medication adjustments. You may benefit from seeing a mental health counselor (like me) help you make such a big lifestyle change. You may enjoy this post I wrote about how psychotherapy can help you stay on keto to improve your mental health.

Just make sure that the counselor is in some small way keto informed (see the blog post about that here).

Otherwise, they may tell you such a diet is dangerous without knowing better, or tell you that you suffer from an eating disorder, without a proper understanding that therapeutic carbohydrate restriction is a research-based medical and psychiatric intervention.

Below are links to some of the resources discussed in this blog post. A few are clearly labeled Amazon affiliate links. I use them to help pay for this blog. Please do not feel obligated to use them.

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