Why does my menstrual cup smell?

Why Does My Menstrual Cup Smell Bad? Remove Funky Cup Odors

You finally did it. Youā€™ve converted to the period cup, learned its ins and outs, and everything is going peachy. Until it doesnā€™t. Whatā€™s going on and why does your menstrual cup smell? Have you noticed a fishy, sour, or just plain weird odor?

We're deep-diving into all things about menstrual cup smells. We'll compare other period products, talk about whether you're cleaning your cup correctly, address some of the causes for a smelly menstrual cup and how to remove unwanted odors. Let's go!

There is no shame in period-related odors, but most of us prefer to avoid or limit them. At Ruby Cup, we're serious about you - as well as people who don't have access to safe menstrual products - having a hassle-free period. With every Ruby Cup bought, we match your purchase and donate a second cup to someone in a developing country. Get your Ruby Cup today.

What's in your period blood


But first, what is period blood made of?

To get a better idea of why your menstrual cup smells, it might be useful to take a look at what constitutes your period blood. And hereā€™s the thing - itā€™s not just blood. What comes out with your monthly flow is a mix of:

  • Blood (of course)
  • Endometrial lining
  • Cervical mucus andĀ 
  • Vaginal secretions

Understanding that there is a delicate ecosystem in your vagina and that your monthly period secretions are a mix of many things helps you see that there could be a variety of reasons for different smells. And many of these smells are completely natural.

What's the risk of smell with other period products?

As you can see there are a few reasons for your period blood causing a potential stink, however, depending on the types of products you use, the smell can strengthen or change. Itā€™s important to remember as well whether each period product absorbs or merely collects of your flow - there is a difference.Ā 


Pads are the most widely used menstrual product for those just starting to menstruate. They are commonly plastic-lined with thicker layers that absorb the blood. There are also reusable cotton pads on the market that offer a more natural solution free of plastic.

Unlike a period cup, pads catch and absorb blood outside of your body. The combination of the collected blood, mixed with a high-humidity area (the vulva) and bacteria creates a stronger smell. The issue with pads is that they donā€™t absorb a lot and need to be changed often. This increases the risk of smell. Itā€™s a common complaint from pad users.Ā 



What about tampons? Tampons are designed with high-absorbing cotton or other materials that are then inserted into the vaginal canal. Unlike pads that absorb your flow outside of the body, tampons do so internally.Ā 

In theory, the smell factor should be much less than a pad because there is no interaction with the air or external bacteria. The risk of smell increases on heavier flow or busy days when itā€™s difficult to change your tampon in time. Although tampons absorb more than a pad, they still donā€™t collect as much as a period cup.Ā 

Some tampons contain chemicals, such as bleaching ingredients and dioxins, that are less than optimal for the balance of your vaginal flora. Vaginas are very sensitive and even a small change in pH balance could throw everything off and cause a smell or change in discharge. On top of this, tampons come with a risk of leaving leftover fibers inside of the vagina every now and then.Ā 

To read more on how tampons and menstrual cups differ you can read our post: Tampons vs Menstrual Cups.


Period Panties

Period panties are relatively new on the market. They offer a sustainable way to deal with your period by absorbing menstrual blood outside of the body (like pads) in a reusable, panty form.Ā 

And the risk of smell? Similar to a pad. Again, think of your flow combined with the natural bacteria in your vagina and other stuff outside of your vagina (sweat, dirt or other bacteria) all sitting in one place for an extended period of time, and oxygen too.Ā 

This could lead to a smelly period! Remember that there is no shame in natural body odors, but you might just feel more comfortable avoiding them. Youā€™ll have to be mindful of changing your period panties often enough if you are aiming at avoiding a strong smell.Ā 



Why Does My Menstrual Cup Smell Bad?

There could be a variety of reasons for a period cup smelling bad. Remember that menstruation is a natural bodily process that sheds the lining of the uterus. This blood (and secretions and endometrial lining), mixed with normal bacteria in the vagina do come with a natural (however light) odor.Ā 

Like all things that are expelled from your body (think: pee, poop, vomit etc) the smells from these things aren't always pleasant. Here are some reasons your cup may smell bad:


1. Leaving it in too long

How long can you leave your menstrual cup in? We recommend 8 hours as a maximum for emptying and rinsing your cup. Although some other period cup companies suggest 12 hours of protection, we prefer to be on the safe side and follow what a number of regulatory bodies around the world - like the Therapeutic Goods Administration in Australia (TGA), and others, recommend.Ā 

The longer you leave your cup in, the higher the chance things can start to smell.Ā 

2. Not cleaning correctlyĀ 

Using a menstrual cup is relatively easy once you get the hang of it. Cleaning your cup correctly is one of the most important steps to having a safe and happy period. Below are some points to take into consideration.Ā 

Only mild soap allowed

A common misconception people have is that cleaning with soap and water is fine when in reality, using soap isnā€™t the best idea. Regular old soap can leave residue on your cup. This residue combined with the bacteria in your vagina could cause your cup to smell. If using soap, make sure itā€™s mild, unscented and oil-free.Ā 

Use cold water

Always use cold water to rinse your cup when you first empty it. Heat (or hot water) can lock smells into the silicone, so use cold water to make sure everything is clean first. Then you can wash with hot water.

Always wash your hands

Proper hygiene is important when using a menstrual cup and helps avoid smells and infection. Wash your hands thoroughly with soap and water before inserting and removing the cup.Ā 

3. Not sterilizing correctly

Just like proper cleaning, sterilizing your menstrual cup after every period is essential to maintaining the integrity of your cup and avoiding unwanted odors.Ā 

So how do you sterilize your period cup? You have 2 options:

Boil your cup

Easy peasy. Just place your menstrual cup into a pot of boiling water and boil for 2-3 minutes.

Use the Ruby Cup Sterilizer

Made with 100% medical-grade silicone, our Ruby Cup Sterilizer is an easy and convenient way to sterilize your cup without using your kitchen pots. Itā€™s also lightweight and collapsible - perfect for traveling!

Just place your menstrual cup inside the sterilizer and fill with water. Either pop it into the microwave or oven to boil for a few minutes - just make sure to keep the lid slightly open. You now have a sterilized period cup ready to use for your next cycle.Ā 

If youā€™re not a Ruby Cup user yet, you can find the cup and sterilizer combo in our shop to get started on your period cup journey knowing that youā€™re on top of the cleaning, care and sterilization of your cup




4. Infection

If accompanied by other symptoms like vaginal discharge, itching, burning or pelvic pain, it may be more than just a "period problem". If you suspect thereā€™s something abnormal happening down there, make a visit to your doctor or gynecologist.Ā 

How to remove smell from a menstrual cup?

Although we recognize that odors are completely normal and should fade over time, sometimes theyā€™re an overpowering smell and something needs to be done. Here are some ways others swear by to remove the smell from a menstrual cup:

  • Use the power of the sun

It may sound strange, but the sunā€™s UV rays have antibacterial properties. Leaving your cup in bright sunlight for a few hours can help remove the smell from a period cup and even bleach light stains. Just make sure itā€™s not at the hottest time of the day so the heat doesnā€™t compromise your cupā€™s integrity.

  • Get cleaning

Are you sure youā€™ve cleaned your cup correctly? Try using an unused toothbrush to scrub the cup clean. Sometimes the suction holes in the top of the cup can get clogged. Try the Squeezeā€™Nā€™Flush method mentioned here. If that doesnā€™t work, you could always try a toothpick to get into the small holes.

  • Try lemon juice

Lemon juice is another one of natureā€™s cleaners. Soak your cup in lemon juice for an hour and clean (or sanitize) thoroughly before using again. Or also here you can use an unused toothbrush for scrubbing a bit of fresh lemon juice onto the cup, which will help with both smells and bacteria, but also potential stains.

  • Cleanse with a sex toy cleaner

You might already have a sex toy cleaner on hand. Sex toys are usually made with the same type of medical-grade silicone as menstrual cups. Plus, because they also enter intimate parts of the body, the cleaners are designed to be gentle and safe on the material. Some of the best cleaners are antibacterial, deodorizing, sanitizing and disinfecting. Make sure you follow the instructions and rinse properly.

  • Use more than one cup

If youā€™re menstruating, chances are youā€™ll be changing your cup every 8 hours. If you arenā€™t able to change your cup that often, it may be a good idea to alternate between 2 so that each one has time to air out between uses.



If you try out any of the methods mentioned in this list, just remember to thoroughly boil your cup for at least 2-3 minutes afterwards. And always make sure to keep good hygiene around your period cup by washing your hands before and after handling it, rinsing it in cold water every time emptying it, and sterilizing it properly between periods.

As you can see, there can be many reasons a menstrual cup could get a smell. As long as you follow proper hygiene rules like:

  • Washing hands thoroughly before handling the cup
  • Regularly emptying your menstrual cupĀ 
  • Rinsing with cold water first
  • WashingĀ 
  • Sterilizing

Your cup and period should be relatively stink-free, and aĀ menstrual cup will help limit smell better than other period products.Ā 


Do menstrual cups smell?

No. In theory they shouldn't. Because they're made from medical-grade silicone the actual cups are designed to be odorless. This type of silicone is medically bio-compatible, meaning it doesnā€™t interact with its surrounds like a pad or tampon might. And since a menstrual cup collects your flow inside your vaginal canal, no one will be able to smell it.

What to do if my menstrual cup smells sour?

A tangy or sour smell in the vagina is normal. The vaginal flora is full of healthy ā€œgoodā€ bacteria, a common one being lactobacilli. These are a species of probiotics that encourage gut and urinary health. Some of the fermented foods you eat like yogurt contain this same type of bacteria which is why some people find the smells similar.

Your menstrual cup may produce a sour smell because itā€™s interacting with this healthy bacteria in the vagina. But itā€™s also possible that itā€™s dirty and needs a proper cleaning. What should you do? Give it a rinse, sterilize it, or try one of the alternative cleaning methods mentioned above.

What if my menstrual cup smells fishy?

If your menstrual cup smells fishy it could be a sign of infection. A fishy odor could be a symptom of a variety of things including:

  • Vaginitis
  • Bacterial vaginosis
  • Trichomoniasis
  • Urinary tract infection (UTI)

If you're experiencing vaginal discharge outside of your menstrual bleeding, itching, burning, or any other irritation, contact your doctor.

Why does my menstrual cup smell like metal?

If you notice that your menstrual cup smells a bit like a copper penny, there's no need for alarm. Menstrual blood contains iron which can lead to the metallic smell. Because the cup has been inside you catching this blood, it's normal. Wash your cup (or sterilize it if the smell is too much) and it should smell fine.

What if my menstrual cup smells (mildly) rotten?

You may also experience a mild rotten smell (although this experience is rare!). This could be a result of blood and tissues exiting the vagina combining with bacteria on the outside of our bodies. Just like leaving a tampon in for too long or not changing your pad, it could be a similar issue. Wash your cup and sterilize.

ā€‹ā€‹What if there was a way to help the planet while feeling happier and freer during your period? There is a way with Ruby Cup! For every cup sold, we donate another one to a person without access to safe period products. Grab your Ruby Cup here.

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