Debunked: 5 Myths About Menstrual Cups

There are so many myths about menstrual cups and menstruation. Does the blood flow back into the womb when the cup is full? Is it true that virgins can’t use period cups? We put all the facts on the table and gathered the most common myths and truths.

Separate the fact from the fiction

1. MYTH: When the cup is full, the blood flows back into the uterus.

TRUTH: Wrong! The blood flows into the vagina and thus into the cup through the tiny hole in the cervix. It is not possible for the blood to flow back into the womb, not even if you're upside down. The muscles of the uterus push the menstrual blood out actively from the uterus.

2. MYTH: You can't use a menstrual cup if you have endometriosis.

TRUTH: Wrong! It is completely safe to use a menstrual cup if you have endometriosis, just ask your doctor first! Read our article ‘What is endometriosis?

3. MYTH: Virgins cannot use menstrual cups.

TRUTH: Wrong! Even people with a uterus who have not had penetrative sex can use the cup. The vagina may occur ‘narrower’ with a virgin vagina, and the hymen may still be present, but these facts do not prevent the use of the cup. At most they'll bring light challenges the first few times of inserting the cup.

4. MYTH: You can go pee/poo or use the toilet while having a menstrual cup inserted.

TRUTH: True! With the cup inserted, you can easily go to the bathroom. This is two of the most common questions we get asked, can you pee with a menstrual cup in? Or can you poop with a menstrual cup in? Of course the answer is yes, you just need to make sure it's not out of place, like during a bowel movement. Good hygiene is essential so that no foreign bacteria enter the vagina or cup. If you want to make sure you're comfortable and clean, remove the cup before going to the toilet and wash your hands (and down there) carefully before inserting the clean cup. You can empty the cup as often as you'd like!

5. MYTH: You don’t need to boil your menstrual cup after every cycle

TRUTH: Sort of. Your menstrual cup does not necessarily have to be boiled every cycle (although we highly recommend it). However, before you use your cup for the first time, make sure to boil it for 20 minutes. Read our article ‘How to clean’ for full instructions. After your first use, boiling it for 10 minutes is good enough. Keep an eye on your menstrual cup when you boil it, you wouldn't want it to forget about it and have it burn at the bottom of the pot! Whatever you do, do not use a hand sanitizer. You can buy cup wipes that are specifically designed for menstrual cups, with no colorants, oils or scents that could damage the silicone. And don’t forget good hand hygiene!

If you’ve still got a question, or want to read more about the things people are curious about, check out our article ‘Everything you’ve ever wanted to ask your OB/GYN’. Alternatively check out our menstrual products.


Hey Michelle,

Great question!

Inserting your menstrual cup in anticipation of your period will not delay your period, but will leave you feeling fresh AF. <3

Just remember that you always need to remove and thoroughly clean your cup within that 12 hour timeframe, even if you’re experiencing a very light flow.

For any other questions, please don’t hesitate to reach out to us at

Lunette Menstrual Mentor June 17, 2019

If you insert cup before your period (in anticipation) will it delay your period?

Michelle June 17, 2019

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