There’s no question that your diet affects your hormone levels, and any diet has the potential to cause changes to your menstrual cycle. The keto diet can cause short-term irregularities in your cycle or return your period back to normal if your cycle is currently out of whack.
How your body responds can depend on a combination of factors, including your current hormonal picture, your overall health, lifestyle, and even how you approach the diet.
Can a Ketogenic Diet Affect Your Period?
The keto diet will affect everyone differently, but it’s important to note here that it’s normal for changes in nutrition and weight to affect your menstrual cycle, too. Overall, keto is a net positive for women with existing health conditions like PCOS that affect menstrual regularity.
Recent studies also point to keto’s effects on menstrual irregularities with unknown causes. In a study of women on either low-fat diets or keto diets, researchers only observed changes in menstruation in the women on keto. (1)
Women observing a low-carb diet reported changes in either the frequency of their periods or the intensity of their periods after starting the diet. Six of them restarted their periods after a long absence.
While keto is an excellent weight loss tool, the participants’ weight didn’t seem to factor into the results. Both groups experienced improved cholesterol levels and body composition. Only those on keto and/or ketone supplements saw menstrual changes. Two were even on contraceptives.
Researchers say this suggests a clear link between blood ketones and menstrual physiology. That’s the biological process that regulates the menstrual cycle and is so important to fertility and overall reproductive health. Keto’s effects on blood sugar fluctuations may be a big factor.
On the other hand, keto can also lead to menstrual irregularities in some women, especially during the initial stages as your body adjusts to the new diet. This is more likely with extremes, like cutting all carbs or introducing extensive fasting, that trigger stress responses in the body.
Keto and menstruation can be combined with an approach that considers your overall hormonal health and allows you to adjust the diet as needed.
Can Keto Help With PMS?
Premenstrual syndrome (PMS) is a catch-all term used for a wide range of symptoms many women experience before the start of their period. PMS symptoms can include headaches, fatigue, cravings, cramping, gastrointestinal issues, irritability, brain fog, or mood swings.
Following a keto diet can alleviate some of these symptoms thanks to its effects on blood sugar, inflammation, and hormonal balance. For example, reducing your intake of carbs can reduce insulin spikes. (2) This may minimize mood swings, irritability, and fatigue associated with PMS.
Let’s look at a few more benefits of keto on PMS symptoms:
- Keto may improve your sleep. If you deal with insomnia before your period, keto’s effects on blood sugar and neurotransmitters like gamma-aminobutyric acid (GABA) can help you get better rest. (3) GABA plays an important role in calming your nervous system.
- Keto reduces cravings. By lowering your carb intake, you’ll automatically control your blood sugar, a common culprit behind sweets cravings. Being in a state of ketosis may also help lower levels of ghrelin, your hunger hormone, to prevent weight gain. (4)
- Keto is highly anti-inflammatory. Inflammation causes hormone fluctuations that can lead to period cramps, gastrointestinal discomfort, and other painful PMS symptoms. A boost in ketones like beta-hydroxybutyrate (BHB) may help block inflammatory responses. (5)
- Ketones support cognition. Many report better memory and concentration when following keto. This is likely due to an increase in the protein brain-derived neurotrophic factor (BDNF) as well as the enhanced bioavailability of ketones in the brain. (6)
Can the Keto Diet Disrupt Your Menstrual Cycle?
We’ve already talked about the positive effects on your cycle after adopting keto, but some women also report irregular periods, heavier bleeding, spotting, and amenorrhea after starting.
While there isn’t much research to support that ketosis itself messes with menstruation, there are things that can happen on any diet to send certain signals to your body. Let’s start with weight loss.
Weight loss can be a great way to balance your hormones and keep your body operating efficiently. When it happens too fast, it can lead to an imbalance in estrogen and progesterone levels and amenorrhea, or the absence of menstruation, and spotting between periods. (7)
Most people on keto also find they’re eating fewer calories than before. While this can be a great thing for body fat loss and BMI, extreme calorie restriction can impact the hormone leptin.
When leptin is in range, it tells your body that it’s safe to reproduce. When leptin signaling dials down, your brain gets the message that it’s not a safe time for reproduction. The result is something called functional hypothalamic amenorrhea. (8)
Functional hypothalamic amenorrhea is your brain’s way of preserving energy for your body but shutting down your menstrual cycle. Stress can have the same effect. If your body is taking in too much stress, it won’t prioritize readying your cycle for reproduction.
How Does Keto Affect Women’s Hormones?
The keto diet can significantly affect hormones like insulin, cortisol, and reproductive hormones. By reducing carbs (and cutting back on sugar), keto lowers blood glucose and insulin levels, which helps combat insulin resistance.
The absence of excess insulin gives your sex hormones a chance to find natural balance. This can improve ovulation, reduce androgens, and improve symptoms of polycystic ovary syndrome (PCOS). It may also prevent type 2 diabetes and obesity, common complications of PCOS. (9)
Keto also influences cortisol, your body’s stress hormone. Much like intermittent fasting, you may trigger a stress response in the short term. Over time, keto’s effects on inflammation reduction and weight management support lower cortisol levels overall.
Finally, ketosis can affect reproductive hormones. Studies show keto may reduce excess testosterone elevated in conditions like PCOS and support a balance of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). (10) Both are important to menstrual cycles and ovulation.
Is Keto Good for PCOS?
Keto can help you manage symptoms of PCOS by addressing root causes like insulin resistance and hormonal imbalances.
Insulin resistance, a common issue for women with PCOS, leads to elevated insulin levels that can trigger excess androgen production. Too many androgens worsen PCOS symptoms like irregular or absent menstrual cycles, infertility, acne, and excessive hair growth, or hirsutism.
By drastically reducing your carbohydrate intake, keto lowers blood sugar and insulin levels, improving insulin sensitivity. This can lower androgens and, as a result, improve ovulation and enhance fertility.
Keto can also make it easier for you to lose weight, a common concern for women with PCOS. Getting to a healthier weight and staying there isn’t just good for your mental health. It reduces your risk of developing type 2 diabetes due to insulin resistance, a key feature of PCOS.
What Are the Potential Side Effects of the Keto Diet on Menstrual Cycles?
We’ve already mentioned how keto can impact your menstrual cycle. Working with your doctor or a dietitian for healthier weight loss can reduce your risk of amenorrhea from losing too much weight too quickly. This could mean keto cycling or boosting your calorie intake for a few days.
In the short term, keto’s effects on cortisol production may disrupt your menstrual cycle, especially if you’re introducing high-intensity exercise into your routine. Doing your best to reduce stress overall as you continue on the diet can support healthier ovulation.
It’s all a delicate balance, and the impact of keto on women’s health can vary widely. Your age, stress, birth control history, and metabolic health are all predictors of how your hormones will react to dietary changes.
You may also already have an underlying hormonal condition causing irregular menstrual cycles that a low-carbohydrate, high-fat diet alone won’t fix. An endocrinologist can help you get to the bottom of a hormonal condition, but there are things you can do on your end, too.
5 Tips to Maximize Keto’s Hormonal Benefits
Your hormonal issues didn’t manifest overnight, so you won’t fix them overnight, either. It may take a few cycles to get back into balance. Before you throw in the towel, try these tips that may help you stay the course and stick to keto.
Track Your Cycle and Hormones
Everyone’s cycle is different, so understanding how your personal cycle works is the first step in taking control of your health and hormones. If you don’t already have some way of tracking your cycle, apps can help. A few examples are:
- Clue (for Apple and Android)
- Cycles (for Apple)
- Dot (for Android)
- Flo (for Apple and Android)
- Glow (for Apple and Android)
- Spot On (for Apple and Android)
A tracker app will help you more accurately plan when your period is going to start and when you can expect to start feeling symptoms of PMS.
You can also keep a hormone journal. It can be very easy to forget how bad your cramps were a couple of months ago when you’re not feeling them anymore. Write down any symptoms you feel throughout the month, and pay attention to where you are in your cycle.
This helps you better identify subtle changes happening in your body before you start addressing them with diet or lifestyle changes. As you make changes, track any improvements to symptoms.
Check Your Thyroid
Low levels of thyroid hormone can reduce sex hormone-binding globulin (SHBG), which is responsible for binding to estrogen and testosterone. (11)
When SHBG is low, estrogen dominance can occur due to a decrease in binding. This can lead to changes in menstruation, weight gain, and mood changes.
The thyroid needs a certain amount of carbohydrates to function optimally. That may sound counterintuitive as we talk about all of the ways keto supports hormone health, but even just 50 grams of carbs a day should be enough to keep your thyroid happy.
If you’re feeling very lethargic or know that you have a thyroid issue, try increasing your carbs slightly to support your thyroid and keep you in nutritional ketosis.
Eat Specific Foods
Certain foods can help you optimize your hormonal health during each phase of your menstrual cycle. You can also use diet to manage PMS symptoms. Here are some ideas for foods to consume at each phase to reduce hormonal dysfunction:
- Follicular Phase: Balance estrogen with cruciferous vegetables (cabbage, broccoli, Brussels sprouts, cauliflower), fiber-rich foods (berries, chia seeds, avocados), and phytoestrogens (flax seeds, sesame seeds, kale).
- Ovulation: Manage cravings and symptoms like bloat and breast tenderness with protein-rich foods (eggs, fatty fish, Greek yogurt), foods with vitamin B6 (chicken liver, spinach, poultry), electrolytes, and keto-friendly snacks to manage cravings.
- Luteal Phase: Reduce inflammation with high omega-3 fatty fish, fight cravings with fiber and protein, and reduce mood swings with vitamin B6 and magnesium-rich almonds, sugar-free dark chocolate, and leafy greens.
- Menstrual Period: Ward off anemia with high-fat, iron-rich red meat, combat cravings and physical discomfort from period cramping with omega-3-rich foods (fish, chia seeds, spirulina), and reduce mood swings with foods high in magnesium.
Take Targeted Supplements
You should always start with diet when targeting your hormonal health, but supplements can help address existing nutritional deficiencies or fill in the gaps where your diet falls short. Here are a few of our favorite supplements for healthier cycles:
- Fiber: Healthy levels of fiber support balanced estrogen levels and a healthier gut microbiome, a key component of hormonal health. (12)
- Fish oil supplements: If you’re not getting omega-3s from dietary sources like fatty fish, try fish oil. Research shows it works better than ibuprofen for period cramps. (13)
- Krill oil: Studies show supplementation with krill oil lowers stress levels, improves mood, and decreases the use of over-the-counter pain medications. (14)
- Magnesium: Studies show this nutrient can reduce food cravings, mood swings, depression, and fatigue during your period. (15)
- Vitamin B6: This one is an all-star in combating PMS symptoms like breast pain and bloating. It may also reduce depression risk when hormones aren’t in balance. (16)
- Vitamin D: Low vitamin D levels are linked to menstrual irregularities. (17) Boost your intake if you think you’re low, especially during seasonal changes.
Prioritize Your Physical and Mental Health
If you’re not moving your body in some way or another every day then you’re missing out on an important aspect of hormone balancing and overall wellness. (18) Exercise can increase metabolic flexibility, help you balance your blood sugar, and increase SHBG.
Exercise can also help you get into ketosis more easily, even after a cheat day, and boost levels of glucagon, a hormone involved in controlling blood sugar.
Another chemical that can wreak havoc on your hormones is cortisol. When you’re stressed out, cortisol increases a response known as the “fight or flight response.”
The big issue with cortisol and hormone balance is that your sex hormones share the same precursor as cortisol — pregnenolone. (19) When stress is high, you use more pregnenolone to make cortisol, leaving little left for your sex hormones. This is known as the “pregnenolone steal.”
Finding ways to deal with your stress is then vital for balancing your hormones. Exercise, meditation, and deep breathing can all be positive destressors. You just need to find the method that works for you.
The Takeaway
While many women report changes in their menstrual cycle during the first few months of keto, many others find a healthier cycle on the other side of keto. Those on the keto diet for periods find that it also benefits blood sugar, inflammation, cravings, and weight management.
If you find yourself with any unwelcome changes to your cycle, there are plenty of modifications to the diet that you can try for healthier hormonal health. You may need more carbs to start or go in and out of ketosis throughout the week on a cyclical keto diet.
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