How Do Menstrual Cups Work? - Types, Safety, Pros, & Cons
Female Body

How Do Menstrual Cups Work? - Types, Safety, Pros, & Cons

Jasmine Chiam Jasmine Chiam

Menstrual cups are the eco-friendly cousin of the tampon and pad. 

And though they've been around for quite some time, they've only just begun gaining popularity due to their environmentally-friendly nature and ability to hold more blood for longer [1]. 

But how do menstrual cups even work? Are they safe to use, and what is the correct method for using them? 

If you wish to know whether the menstrual cup is a suitable menstrual hygiene product for you, continue reading. 

We'll explore what a menstrual cup is, the different types of cups available, the right method of using it, and the pros and cons of its use. 

What are Menstrual Cups & How do Menstrual Cups Work? 

The menstrual cup is a reusable menstrual hygiene product with a small, flexible, and funnel-shaped cup. It's made up of silicone, thermoplastic elastomers (TPE), or rubber and can be inserted into the vagina to collect blood during menses [1]. 

Menstrual cups are folded before being inserted into the vagina. Once in place, they spring open and back to their original shape, forming a leakproof 360° seal against the vaginal wall [1]. 

The menstrual cup doesn't absorb the blood like a pad or tampon. Instead, it will collect menstrual blood in its funnel-like cup as you go about your day. Your vagina will naturally hold the menstrual cup in place, which can be kept in for up to 12 hours at any time [1]. 

After that, the menstrual cup is removed and cleaned before being reused.

Types of Menstrual Cups Available 

Just like pads and tampons, menstrual cups come in wide varieties. These differ based on size, shape, firmness, and material [1]. 

Choosing a suitable menstrual cup can be a little tricky since these factors can change how well it fits into your vagina. 

Let's explore each of these four factors a little further: 


Cup manufacturers typically offer two options—smaller menstrual cups for those younger than 30 who have not been pregnant or given birth and larger menstrual cups for those older than 30 or with a history of childbirth or pregnancy. Sometimes, you may find even smaller menstrual cups for beginners or teens [1]. 

Confusingly, the sizing of menstrual cups doesn't necessarily relate to how much blood they can hold. Because there is no standardization in sizing, manufacturers make size recommendations based on different factors, such as flow, age, pregnancy history, the height of your cervix, and your experience with menstrual cups [1]. 


The four main shapes of menstrual cups are bell-shaped, V-shaped, round-shaped, and asymmetrical-shaped. Choosing the right type of shape depends on the anatomy of your vagina and cervix, and it may take some experimenting to find what best fits you [1]. 


Firmness refers to how much force is needed to compress the cup. A menstrual cup that is too soft may not open up correctly in the vagina and lead to leakage. Meanwhile, a menstrual cup that is too firm might be uncomfortable or cause injury [1]. 


Most menstrual cups are made from medical-grade silicone. Some research shows that the material used doesn't exactly relate to how firm the cup is, so picking the best material for yourself may require a little experimentation [1]. 

If you're allergic to latex, it's best to avoid cups made from natural rubber. 

How to Use a Menstrual Cup

When you first use a menstrual cup, expect a learning curve. It may take a couple of months to get used to inserting and removing a menstrual cup. And don't worry; that's perfectly normal. 

Here's how you can insert a menstrual cup into the vagina [1]: 

  1. Wash your hands with soap and water. Before inserting the cup, you may wet it to help it slip in easily. 
  2. Fold the menstrual cup. The simplest way to do this is to fold it in half to form a "C" or "U" shape. Another method, called "punch down," involves pushing down one side of the rim into the cup. Alternatively, you can do the "7-fold," where you'd flatten the cup and pull one end of the rim diagonally to the other end to form a "7." 
  3. Guide the rim into the vagina to insert the cup. 
  4. Once the cup is in place, make sure the cup is fully open by running your fingers along the side of the vessel to look for any bumps (which signifies that the cup did not open correctly). 

Depending on how heavy your flow is, menstrual cups can be worn for up to 12 hours at any one time [1]. 

Here's how you can remove a menstrual cup [1]: 

  1. Wash your hands with soap and water. 
  2. Avoid removing the cup straight out by tugging at the stem. Instead, look for the bottom of the cup and pinch it to break the seal. 
  3. Once the suction releases, you can then remove the cup. Some people may sway it from side to side to help with the removal. 
  4. After removing the cup, empty the cup into the toilet. Then, wash it with fragrance-free soap and water. If you're in a public restroom, you may simply clean the cup with toilet paper after emptying it. When you get the chance, you can then remove your cup, empty it, and wash it before reinsertion. 

When it comes to inserting and removing your menstrual cup, practice makes perfect. It may take a few leaks and tries before you master this process, so you can use a pad or panty liner for extra protection when you first start using the menstrual cup. 

Can I pee or poop while using a menstrual cup? 

Yes, you can pee or poop with a menstrual cup inserted, and that's because the menstrual cup goes into your vaginal canal. 

On the other hand, urine comes out of the urethra, a separate tube that carries urine from the bladder out of your body, while stool comes out of the anus. 

Because of this, a menstrual cup won't block poop or pee from coming out. 

Can I sleep while using the menstrual cup?

Menstrual cups can be worn for up to 12 hours, so they can be left in overnight [1]. If you have a heavier flow, you can empty your cup before sleeping and choose a suitable cup that can hold a larger volume of blood.  

If you're worried about leaks, using a pad can help prevent any mess. But with proper insertion, this is unlikely—they're a great way to avoid a mess from, let's say, a pad that shifted or bunched up during the night. 

Can I have sex with the menstrual cup?

Reusable menstrual cups can be quite thick and firm, so having sex with them in might be uncomfortable. That said, some menstrual cups in the market are specifically designed to facilitate penetrative sex. 

Can I use a menstrual cup if I have an IUD?

Studies show that using menstrual cups with an IUD may increase the risk of IUD expulsion, which is when your IUD falls out of your uterus [2]. However, more research is required to back these findings up. If you have an IUD and want to start using menstrual cups, it's best to consult your healthcare professional beforehand. 

Is the Menstrual Cup Safe? 

The majority of research studies show that menstrual cups are safe [1]. When used correctly, the menstrual cup is unlikely to lead to any harm. 

However, there are some rarer reported cases of complications and injuries. If the menstrual cup is misused, this could lead to pelvic organ prolapse, a condition where your pelvic muscles can no longer support the organs in your pelvic region [1]. 

In very rare cases, it could also cause renal colic, which is the pain you get when your urinary tract is blocked by the menstrual cup [1]. 

Should I use a Menstrual Cup? 

According to scientific evidence, the menstrual cup is durable, safe, comfortable, and convenient (since it can hold more blood for longer). 

Menstrual cups are also a fantastic way to save money and reduce waste. In fact, studies have shown that the long-term use of menstrual cups equates to less than 5% of the financial costs and less than 0.4% of the environmental waste associated with pad usage. Similarly, for tampons, menstrual cups produce less than 7% of the financial costs and less than 6% of the plastic waste produced by tampon usage [3]. 

Research also suggests a lower risk of fungal and bacterial infections with menstrual cups compared to pads or tampons [3]. 

However, choosing the right menstrual cup, including its size and shape, can be challenging, as there is a lack of standardization in measurements and features from one manufacturer to another [1]. Learning how to use one may also pose challenges of its own. 

How Can I Measure Blood Loss When Using the Menstrual Cup? 

Depending on the size of your menstrual cup, it can typically hold around 18 to 38 mL of blood [1]. Some menstrual cups even come with markings showing the estimated blood loss volume based on how full the cup is. 

Because the menstrual cup collects blood rather than absorbing it, you can more easily tell how much blood was lost compared to using a tampon or pad. 

Knowing how much blood you lose each cycle is an indicator of your menstrual and hormonal wellness. But you can keep track of several other indicators, including your menstrual symptoms, timing, and duration, to better understand what's normal (and what's not) for you.

The inne minilab and smartphone app do just this. The inne minilab detects and measures your hormone through daily saliva tests, while the app keeps track of your hormonal curve based on these readings. 

Through the app, you can take note of your hormonal changes, menstrual timing, ovulation, and other facets of your reproductive health!


  1. Manley, H., Hunt, J. A., Santos, L., & Breedon, P. (2021). Comparison between menstrual cups: first step to categorization and improved safety. Women’s Health, 17, 174550652110585.
  2. Long, J., Schreiber, C., Creinin, M. D., Kaneshiro, B., Nanda, K., & Blithe, D. (2020). Menstrual Cup Use and Intrauterine Device Expulsion in a Copper Intrauterine Device Contraceptive Efficacy Trial [OP01-1B]. Obstetrics &Amp; Gynecology, 135, 1S.
  3. van Eijk, A. M., Zulaika, G., Lenchner, M., Mason, L., Sivakami, M., Nyothach, E., Unger, H., Laserson, K., & Phillips-Howard, P. A. (2019). Menstrual cup use, leakage, acceptability, safety, and availability: a systematic review and meta-analysis. The Lancet Public Health, 4(8), e376–e393.

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