If you’re on the keto diet, you might have heard about keto flu, or even suffered from it yourself. But just what exactly is it? How do you know if you have it? What can you do to avoid or prevent it in the future? In this article, we’ll answer all of these questions and more so that you’ll be able to take full advantage of the ketogenic diet without compromising your health in any way.

Is it real?

We’ve all been there: you decide to give a low-carb diet, like keto, a try and it works great. Then after a few days, you feel sluggish and out of it. This is commonly referred to as keto flu. It isn’t the flu or any other illness, but rather symptoms of adaptation that your body goes through as it adapts to using fat for fuel instead of carbohydrates. The good news is that these symptoms are typically only temporary. In addition, if you were already feeling tired or under-rested before beginning keto, then these symptoms may be worsened by dehydration and lack of sleep (both common causes of fatigue).

How do you know if you have it?

The keto flu isn’t a medical term. It’s a name for some of the physical symptoms that people sometimes get when they start following a ketogenic diet. On average, it takes about one to three weeks for someone to feel better. The specific symptoms can vary from person to person and may include: Headaches

How long does it last?

For most people, keto flu is a short-term issue. It typically lasts one to two weeks and occurs because your body is making more fat-burning ketones than it’s used to and you’re not yet a pro at burning them. The solution: ease into things slowly by easing off your carb intake (take it down to 20 percent of your total calories) while ramping up exercise and, of course, increasing water consumption. Once you get through the keto flu, you’ll experience more stable energy levels and better mental clarity than when you started.

How can you fix it?

The keto flu can be difficult to deal with, especially if you aren’t expecting it. There are a few things you can do to help yourself manage, though. Getting extra salt (as opposed to processed salts) and staying hydrated is important, as is eating small meals throughout your day instead of large ones. You may want to try adding in some electrolytes by drinking coconut water or sucking on a tablespoon of coconut oil — some people find that helps minimize symptoms dramatically. It’s also important not to push through keto flu symptoms too quickly; taking it slow will help you avoid overwhelming your body and setting yourself up for long-term failure on keto.

Is there any risk of keto flu?

Some people feel a little off when they first start keto, but that feeling doesn’t mean anything is wrong. It’s usually just referred to as keto flu, and it goes away after about a week or two. If you do experience some of these symptoms, know that it’s nothing to worry about—they go away on their own after you acclimate to your new diet. Don’t believe us? Read what one of our community members had to say about her experience with keto flu: I had all of these side effects come at once...that lasted for around a week. But by Week 2, almost everything subsided except for an occasional headache.

Final words about keto flu

Ketosis comes with some symptoms you'll want to be aware of before committing to cut out carbs. The most common symptom is keto flu—headaches, nausea, fatigue, and irritability that typically lasts one to two weeks in healthy people (but as long as four weeks in those with risk factors like diabetes). Once your body adapts to using fat for fuel, though, it should all pass—just make sure you drink plenty of water and eat enough salt while you're going through it. And remember: even if keto doesn't work for weight loss or overall health (more on that here), it's still worth trying because of its potential effects on mental health issues like anxiety and depression.