Does going vegan impact your menstrual cycle?

Does going vegan impact your menstrual cycle?

What is a vegan diet?

A vegan diet is a diet that abstains from any animal products such as meat, eggs and dairy. Vegan diets have been growing in popularity in the last few years, with market research showing that more and more individuals are consuming vegan products. Individuals may choose to go vegan or plant-based for the environment, the animals, and their health. Plant-based diets are usually higher in fibre, folate, phytochemicals and antioxidants whilst being lower in saturated fat. These nutritional components can be incredibly health-promoting and reduce the risk for certain diseases such as cardiovascular disease and diabetes


However vegan diets tend to be lower in certain important nutrients such as protein, omega-3 fatty acids, iron, calcium and vitamin D. Plant-based foods also contain anti-nutrients such as phytic acid, tannins, oxalic acid and polyphenols that bind to and inhibit the absorption of essential minerals such as iron, calcium and zinc. Eating a diverse range of whole foods, eating enough and supplementing as necessary (such as vitamin B12) is required to ensure you meet your nutritional needs.

1. Firstly, what’s the difference between a plant-based diet and veganism?

Although “plant-based” and “vegan” are terms used interchangeably, it’s important to know the difference between the two. A vegan diet restricts all animal-based foods such as dairy, meat, fish, poultry and honey. A plant-based diet refers to a diet that’s mostly (or sometimes fully) free from all animal products and is predominately based on eating plants such as nuts, seeds, whole grains, fruits and vegetables.

Veganism is often not a dietary choice but a lifestyle, and many vegans will abstain from using non-vegan beauty products, clothing and any practices that will harm animal welfare. Also, some individuals may start from consuming a plant-based diet and later switch from eating a completely vegan diet and lifestyle.

2. Can a vegan diet affect my menstrual cycle?

Absolutely, with any dietary change, there is a potential impact on our periods. Eating too much, or too little or changing up what we eat can affect all of our bodily systems including the female reproductive system.

However, it’s also important to note whilst our diet has a huge influence on our hormones and menstrual cycle, many other factors can also affect our periods. These include psychological stress, exercise, travelling, age, body mass index (BMI), sleep and drugs (such as the oral contraceptive pill and prescription drugs). Hence, it’s important to also consider these factors if you’ve noticed your period has changed after going vegan.

3. Do vegans have less period pain?

A plant-based diet can be good for period pain, but this is highly dependent on the quality of the diet. Certain nutrients have shown to support hormonal balance and reduce the inflammation which causes premenstrual syndrome (PMS) symptoms. These include calcium, vitamin D, magnesium, B vitamins, iron and zinc. Vegans must ensure they are meeting adequate amounts of these nutrients as these nutrients are often harder to obtain and absorb in plant-based diets (more on this later!).

In contrast, vegan diets can be higher in antioxidants and greater plasma levels of antioxidants have been associated with reduced risk for painful periods. Antioxidants have powerful anti-inflammatory effects on the endometrium and reduce prostaglandins which cause painful periods. So, in some cases, vegans have less painful periods if they eat an abundance of antioxidant-rich foods (such as kale, berries, sweet potato, cacao and tomatoes).

Cutting out dairy can affect your period and some vegans will notice reduced pain when they switch to dairy-free diets. In some individuals, A1 casein, a protein in cow’s milk, can increase inflammatory markers, histamine and mast cells which increase period pain and bleeding.

4. Will going plant-based reduce my bleeding on my period?


Vegans have shorter periods on average compared to non-vegan, and researchers believe this may be due to lower iron intakes, lower body weight and greater intake of phytoestrogens in vegans. Phytoestrogens are phytochemicals found in plant-based foods such as soy, legumes, grains and nuts. Phytoestrogens have an anti-estrogenic effect meaning they counteract the effects of estrogen and greater intake of phytoestrogens have been associated with shorter cycles.

5. Why do vegans lose their period?

There are multiple reasons why vegans may lose their periods after making the dietary shift. Vegan diets are more calorically dilute compared to an omnivorous diet and our hormones are incredibly sensitive to any energy shortage. When we don’t eat enough it can affect the regularity of our periods or even cause them to stop. Also, all our hormones are made from fat (cholesterol) and not consuming enough fat (such as avocado, flaxseeds oil, almonds) can prevent our bodies from making the necessary sex hormones such as progesterone and estrogen.

Eating disorders can cause our periods to stop (“amenorrhea”). Some individuals may also choose to go on a vegan diet due to their eating disorders or disordered eating habits as a means to restrict their diet. A study published in 2013 found individuals with an eating disorder or a history of an eating disorder were significantly more likely to be vegetarian in the past or present. Also, individuals who adopt a vegan diet for weight loss are more likely to experience menstrual disturbances.

6. Is there a detox period when going vegan?

You may notice going vegan will make your bowel movements very regular, this is due to the higher water and fibre content found in plant-based foods. Fibre and water add bulk to stool and individuals who follow a plant-based diet report to experiencing less constipation.

Regular bowel habits are incredibly important for the healthy excretion of excess sex hormones. When we have excessive amounts of female sex hormones such as estrogen, we can run into issues and suffer from heavy periods, painful periods, breast tenderness, irritability and mood swings. Over time, excess estrogen can increase the risk for estrogen-dependent diseases such as breast and colorectal cancer.

7. Can vegan diets help with weight loss if I have PCOS?

Vegan diets tend to be lower in fat, higher in fibre and more calorically dilute compared to non-vegan diets which can aid in weight management. Epidemiological studies have shown that vegans tend to have a lower BMI compared to omnivorous individuals. Whilst other health-promoting factors may have influenced this observation such as exercise, one 2-year study found individuals who consumed a vegan diet lost a significant loss of weight compared to individuals who consumed a low-fat diet.

A healthy body weight is incredibly beneficial for women with polycystic ovarian syndrome (PCOS). Obesity is positively associated with insulin resistance and is one of the major contributing factors in the pathogenesis of PCOS.

8. Can being vegan decrease my fertility?

Firstly, it’s important to note that the world health organisation has announced that a vegan diet is suitable for all life stages including pregnancy, breastfeeding, lactation and infancy. Research has shown vegans have lower rates of C-sections, neonatal death, postpartum depression and plant-based diets may reduce the risk of pregnancy-related conditions such as pre-eclampsia, gestational diabetes and excessive weight gain.

However, there is increased potential risk for nutritional deficiencies such as protein, iron, calcium, iodine, omega-3 and B vitamins which are all important nutrients to support healthy hormones, pregnancy and fertility. Poor dietary intake of these nutrients can result in vegans having trouble falling pregnant and having more miscarriages. I highly encourage all women (not just vegan!) to seek out nutritional guidance and support when they are planning to or have recently fallen pregnant.

9. So, what can vegans eat for a healthy menstrual cycle and female hormones?

With any diet, eating a diverse range of minimally processed foods and eating to meet our energy requirements is crucial to support a healthy menstrual cycle. We can meet all our nutrients (except vitamin B12) from a vegan diet. Aim to focus on these nutrients which can harder to obtain on a vegan diet below:


You don’t have to eat meat to get your protein, there are so many plant-based protein options out there! However, plant protein sources are often ‘incomplete’ proteins meaning that they don’t contain all the 9 essential amino acids that we need (animal sources are ‘complete’ protein sources). It’s important to make sure you’re eating a variety of vegan protein sources to ensure you’re meeting all your essential amino acids requirements. Vegan foods that are high in protein include tofu, tempeh, lentils, chickpeas, nuts, chia seeds, spirulina, quinoa, peas and hemp seeds.

Omega-3 fatty acids

Our bodies need fats to have healthy hormones as fats are what hormones are made of. Omega-3 fatty acids are “good fats” and help to reduce inflammation, painful periods, mood disorders and stress. The three main types of omega-3 fatty acids are ALA, DHA and EPA. Usually, plant-based foods only contain ALA which is less absorbable and must be converted to DHA and EPA.

But our body can only convert a small amount of ALA into DHA and EPA. Furthermore, studies have found individuals who consume a plant-based diet have low plasma EPA or DHA levels. Therefore, vegans should consume a higher amount of omega-3 fatty acids than what’s often recommended. Vegan sources of omega-3 fatty include flaxseed oil, tofu, walnuts, chia seeds and flaxseeds.


Iron is an essential nutrient for blood production, energy, cognition, immunity, mood and for preventing iron deficiency anaemia. Menstruating women are prone to iron deficiency anaemia as we lose blood every month on our periods (especially if we suffer from menorrhagia or ‘heavy bleeding’ during our cycles). Animal-based foods such as red meat, poultry and seafood are the top sources of iron and contain ‘haem’ iron which is a form of iron that’s easily absorbable.

Vegetarian sources of iron contain non-haem iron which is a less absorbable form of iron. However, you can increase your absorption of iron by consuming iron-rich foods with vitamin C (e.g., spinach, capsicum, broccoli, tomato and chilli). Vegan iron sources include kidney beans, lentils, dark leafy greens, cashews, fortified cereals, dried fruit and tofu. I strongly recommend increasing the intake of these iron-rich foods for vegans to eat on their period.


Calcium is required for strong bones, healthy teeth, muscle contractions, a healthy nervous system and blood clotting. Adequate calcium intake has also shown to help reduce premenstrual syndrome symptoms such as water retention, anxiety, and depression. Calcium intake may be low in vegan diets as most people obtain the majority of their calcium from dairy products (such as milk, yoghurt and cheese) and oily fish. Also, calcium absorption is decreased due to certain nutrients found in plant-based foods such as oxalates and phytates in spinach and rhubarb.

You can obtain calcium as a vegan from calcium set tofu, fortified nut milk and milk products, fortified cereals, fortified orange juice, legumes and dark leafy greens. A handy tip is to shake the container of your fortified orange juice or nut milk to improve calcium absorption as the calcium added to the drinks can settle to the bottom of the containers.


Zinc is a nutrient that is involved in cell growth, skin health, immunity and protein metabolism. Like iron, zinc is not as readily absorbable in plant-based foods. Zinc absorption is inhibited by phytic acid which is found in whole grains, legumes and nuts. Some studies have suggested zinc requirements are 50% higher for vegans but other studies have shown that individuals on long term vegan diets adapt to lower zinc absorption rates. Vegan sources of zinc include hemp seeds, wheat germ, tofu, pepitas, legumes and quinoa.

Vitamin D

Vitamin D helps to absorb calcium, important for immune health, regulates insulin, promotes healthy bone density. Vitamin D supplementation has shown to decrease insulin sensitivity and decrease androgen (male sex hormones) in women with PCOS. There are few plant foods fortified with vitamin D3 (fish, egg yolks, etc). Consume fortified grains, sun-soaked mushrooms and get appropriate sun exposure (vitamin D3 is synthesised in the skin of humans from the sun).

UVB radiation from the sun is the best source of vitamin D but our ability to obtain adequate amounts of it is highly dependent on our location, weather, the time of year, and the colour of our skin (individuals with darker skin require more vitamin D from the sun as their skin has higher melanin pigment).

Also, remember to stay sun safe and keeping sun exposure to a safe and appropriate amount. Download the “Sun Smart app” or referring to the “Bureau of meteorology” to check the UV levels and use sun protection as necessary. The best time for sun exposure is around mid-morning or afternoon.

Vitamin B12

Vitamin B12 helps produce energy from foods, is involved in DNA synthesis and red blood cell production. Vitamin B12 deficiency can result in symptoms such as tingling, numbness, poor memory and hallucinations. Also, vitamin B12 supports the breakdown and excretion of estrogen. Hence, vitamin B12 deficiency can result in excess estrogen or estrogen dominance resulting in hormonal imbalance.

Vitamin B12 is only derived in animal-based foods (and in some fortified foods).

Fortified foods with vitamin B12 include some fortified milk, fortified cereals, nutritional yeast and marmite. However, the amounts of vitamin B12 vary from food types and brands. Hence, to ensure adequate intake supplementation is required.

As vegan diets tend to be lower in calories and more filling due to their high fibre content, we mustn’t accidentally undereat. Eating whole, nourishing foods such as avocadoes, sweet potatoes, chia seeds, extra virgin olive oil, walnuts, brown rice and dark chocolate are delicious ways to increase our calories.




10. How can I improve my nutrient uptake as a vegan?

Some plant-based foods contain ‘anti-nutrients’ such as oxalates, tannins and phytates which inhibit the absorption of certain nutrients (e.g., iron, zinc, calcium). Spinach is one vegetable that’s high in calcium, but the amount of calcium we’re able to absorb is low due to the high oxalate content.

However, there are ways around this. Certain food processing methods such as cooking foods (instead of eating them raw), soaking beans/legumes/grains/seeds overnight (can reduce anti-nutrients by 25-100% but do this in the fridge and never consume them raw to prevent possible bacterial contamination) and eating iron-rich foods with vitamin C can increase nutrient absorption.

11. What do I eat for a healthy vegan diet and menstrual cycle?

Breakfast: oatmeal cooked using fortified soy milk and sprinkled with “Earth seeds”, fruits of choice, cinnamon and almond butter

Lunch: Mexican inspired quinoa with roasted vegetables, herbs, avocado, salsa, black beans, corn and drizzled with tahini

Dinner: lentil dahl using “Luna’s Gold” with brown rice, coconut milk, pumpkin, red onions, cauliflower, garam masala and coriander

Snacks: beetroot bliss balls made using dates, coconut flakes, cashews, “Luna’s Beets”, maple syrup and chia seeds

Drinks: matcha latte made from “Luna’s Matcha’s” and hot cacao made from “Luna’s Lover“ with coconut milk

Disclaimer, this is one example of one day and everyone’s needs will be different based on their life stage, age, activity levels, stress levels, etc. Please use this as a guide and remember to supplement with vitamin B12 as this is the only nutrient that you cannot find in a vegan diet!



Everyone’s dietary choices are completely their own choice and there is no perfect diet that will suit you. It’s important to ensure you are meeting all your nutrient requirements and eating enough on a plant-based diet. If you find yourself experiencing changes to your hormones and periods such as irregular or absent periods, it’s important to flag this immediately to a health care practitioner.


Finally, I believe anyone can benefit from eating more vegan foods such as fruits, vegetables, legumes and whole grains as these are incredibly health-promoting. Often, it’s not the diet that matters, but the quality of the food we consume. If you’re looking for more information to support your hormones and menstrual cycle, I recommend checking out our “Happy hormones, happy periods e-book bundle” which covers useful information such as dietary guidelines which can help guide you through a healthy vegan diet and menstrual cycle.






Clinical Nutritionist Judy Cho,




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