How Keto Affects your Period

If you’ve been doing Keto for a while you probably feel great! You might be losing weight, bursting with increased energy and getting a fantastic night’s sleep. But what happens when a pesky side-effect comes along such as missing your period? Menstrual irregularity happens occasionally after you’ve been on Keto for a while; however, there are some things you can do to prevent it and to help your cycles return to normal if you’re experiencing an irregular period. The following article will explain what you can expect on Keto in terms of your menstrual cycle when to be worried and what you can do in order to get back to feeling amazing!

What effects can Keto have on your period?

The majority of people on Keto won’t experience any changes to their menstrual cycle. In fact, if you’re overweight or at an average weight, you most likely won’t have to worry about this. Irregularities with the menstrual cycle usually happen when your body weight drops below a certain threshold so chances are, the only women who will have to watch out for this are ones that are already thin when they begin Keto. That being said, there is evidence that the Keto diet can lead to irregular periods or missed periods in some women.

Why does Keto cause irregular or missed periods?

There are four main reasons that you might miss your period. Weight loss, strenuous exercise, lack of nutrients and hormonal imbalances can all lead to irregular menstrual cycles. As you can probably tell, Keto checks a few of these boxes.

When you begin Keto it’s often because you want to lose weight. If you’re doing Keto properly you will see weight loss. However, sudden weight loss or weight loss that puts your body below what it feels comfortable with will put a pause on your periods. Your body is a fine-tuned survival machine and any threat to its survival causes it to make changes by cutting off energy to systems that it doesn’t see as necessary. When our ancestors experienced drastic weight loss it was their body’s signal that food is scarce and it’s not a good time to reproduce. This means that menstrual cycles would be halted until there was a rise in weight and the body felt comfortable that there were enough nutrients and fuel to support the growth of another human.

Weight loss can also affect your menstrual cycles because of its effect on your hormones. As your weight drops, so does estrogen which is a hormone that plays a large role in your menstrual cycles. The Keto diet can also affect the leptin and luteinizing hormones associated with your period. Leptin is more commonly associated with your appetite and hunger; however, it appears as though it may play a role in regulating your menstrual cycle. Because it’s also tied into hunger it’s a hormone that’s acutely aware of when your body enters any type of starvation which means that it can cut off your menstrual cycle to conserve energy if it feels as though you’re not getting enough calories or nutrients.

The GnRH (or gonadotropin-releasing hormone) can also be affected by weight loss on the Keto diet. This hormone is responsible for sending signals to your FSH (follicle-stimulating hormone) and LH (luteinizing hormone) hormones to signal your body to begin producing estrogen and progesterone so that your ovulation cycle can begin. The more weight you lose, the more the GnRH levels are affected and the greater the likelihood that you’ll experience irregular periods or miss them altogether.

Scientific studies haven’t shown any connection between the Keto diet specifically and missed periods. The key to the Keto diet is cutting your carbs down to very low levels. From the current research being done, it appears as if low carb levels on their own aren’t enough to cause irregular menstrual cycles so the Keto diet carries the same risk as any other diet or weight loss program. It is possible that when following a Keto meal plan that you’re not getting enough essential nutrients which can be a contributing cause to irregular periods. 

Should you be worried?

If you do experience a missed period or two while on the Keto diet it doesn’t necessarily mean that there’s something to worry about. It does mean that you should talk to your doctor. There are many reasons that your menstrual cycle can become irregular, and in order to rule out a larger issue, you should consult with a medical professional. They’ll know what to look for, what to worry about and what you can do to get things back to normal.

If you experience missed periods for a long period of time it can turn into a problem in the long run. When your levels of estrogen are too low for too long you might begin experiencing bone density loss. In the short term, low estrogen levels can lead to problems such as vaginal dryness, increased susceptibility to UTI’s, headaches, hot flashes, mood swings and even depression. So if you’re experiencing any of these symptoms then it could be a warning sign that your estrogen levels are too low. Now, this isn’t necessarily tied into your Keto; however, you should speak with your doctor to get to the root of the problem and find a solution.

If you miss your periods too often or if they become irregular and you’re unsure as to when your next one is coming then this means that it’s affecting your fertility. If you’re not looking to become pregnant, this in itself isn’t something to be concerned about; however, if you want to become pregnant in the future it’s a good idea to address the problem now. That way you can better track your cycles and know when you’re ovulating which will make getting pregnant easier. Because it can take a few months for your cycles to resume after they’ve been interrupted it’s a good idea to get them back on track as soon as possible.

What can you do?

If you’re dealing with irregular menstrual cycles don’t panic! There’s plenty of things that you can do to get things back on track without abandoning your Keto diet. The first thing you should do is speak to your doctor. This is a good idea so that you can pinpoint the cause of the problem. There’s a very good chance that it doesn’t have anything to do with your diet at all and you can keep eating according to your Keto meal plan. If it is in relation to your Keto then your doctor can work with you to come up with a solution.

 If your doctor is concerned about your low estrogen levels then there are supplements that you can take to increase these levels. You can also eat foods such as flaxseeds that are rich in phytoestrogens. Phytoestrogens act like estrogen and bind to the estrogen receptors in your body. Since flaxseeds are a great source of nutrients on Keto it’s a good idea to add them into your diet regardless but they can help with low estrogen as well.

Nutrients play a large role in the regularity of your menstrual cycles. Because you’re cutting out an entire macronutrient while on Keto it’s possible that your body might be lacking in some of the nutrients that it needs. Take a close look at your Keto meals and figure out which nutrients your food is providing and which ones you might be lacking in. Between all the vitamins, magnesium, potassium, calcium and fibre it’s easy to find yourself lacking in one or more of the essential nutrients that your body needs.

Calorie restriction can also play a role in changes to your menstrual cycle. If your calories are restricted too sharply your body will stop your period because it feels as if it’s being starved. The Keto diet doesn’t restrict calories; however, if you’re cutting out carbs and not replacing those calories with Keto-friendly ones then you might find yourself in too much of a calorie deficit. If this happens gradually increase your calories by 100cal a week until your period resumes.

If your period has stopped because you’ve lost too much weight then it’s important to find your body’s sweet spot. Everybody has a balance with their weight where their body just hums along happily. You may think that you look great at a lower weight but your body might disagree if it feels that it can’t perform the tasks it needs to in order to keep you moving and thriving.

If your doctor feels that a lack of carbs is a problem then you can start by increasing your net carbs to the maximum allowed on your Keto plan. For example, if you’re allowed to eat 25g of net carbs daily and you’re only eating 15g then you have a little bit of leeway to raise your carb count a bit. This little bit might be enough to tell your body that it’s safe to start allocating energy to your menstrual cycle. If this isn’t enough to kickstart things again then you might want to consider switching to cyclical Keto. Cyclical Keto is where you follow a Keto meal plan for 5 days out of the week and for the remaining 2 days you eat a higher carb diet. Adding these additional carbs into your diet can help make your body feel safe and get your menstrual cycle back on track.


You may or may not have to deal with irregular or missed periods when you’re on the Keto diet. If you do experience irregularity you should speak with your doctor before ruling out any external possibilities. Together you can choose the best solution to get your cycle back on track.

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