Menstrual cups are devices that collect menstrual blood internally. Unlike tampons, they do not absorb blood but collect it in a silicone or soft plastic cup. With proper use, they are safe to use.
However, similar to tampons, menstrual cups do have some potential risks, particularly if a person does not use them correctly.
This article looks at some of the potential dangers of using menstrual cups.
In most cases, menstrual cups are not dangerous, as long as people follow the manufacturers’ instructions.
A systematic review in The Lancet looked at 43 studies on the safety of menstrual cups, which involved 3,319 participants in total. The researchers concluded that menstrual cups are a safe way of managing periods.
There is also no evidence to suggest that menstrual cups are any more dangerous than other internal period products, such as tampons.
Although many people use menstrual cups without experiencing any complications, there are some potential risks to using them. Many of these risks are similar to those of using other internal menstrual products.
Researchers have identified the following risks:
- pain or minor injuries
- allergic reactions
- urinary problems
- dislodging an intrauterine device (IUD)
- toxic shock syndrome (TSS)
As with any other menstrual product, menstrual cups can leak during use. Leakage is more likely if the cup is full or does not fit well.
Emptying the cup regularly and using one that fits well reduce the chance of leaks. A menstrual cup that fits well will create a “seal” around the vaginal wall, and it will not move much during the day.
Pain and minor injuries
Inserting any object into the vagina can cause pain or small injuries. A person is more likely to experience these issues if they insert a menstrual cup roughly, have long nails, or use a cup that is too large.
The comprehensive review in The Lancet only found five people (0.15% of the participants) who experienced severe pain or injury while using a menstrual cup. The researchers suggest that this could be due to differences in anatomy or the cup being in an incorrect position.
Rashes and allergic reactions
Any product can cause a skin allergy or allergic reaction. In rare cases, this can also occur in people using menstrual cups. The Lancet review found only six cases (0.18% of the total) where cups caused an allergic reaction or rash.
As the materials that companies use to make menstrual cups can vary, some people may find that certain brands work better for them than others.
Inserting any object into the vagina can irritate the urethra and introduce bacteria to the urinary tract. A small number of people find that this occurs when they use menstrual cups.
Additionally, in rare cases, the cup may push up against the urethra and block it, leading to problems urinating.
The Lancet review identified nine people (0.27%) with urinary symptoms, three of whom developed hydronephrosis — a serious condition that causes swelling in the kidney when urine cannot escape.
Medical scans showed that in all three of these cases, the menstrual cup was not in the correct position, which may have been the cause.
IUD dislodgment or expulsion
Some evidence suggests that menstrual cups can dislodge IUDs, which can mean that they are no longer effective for preventing pregnancy. The Lancet reported that menstrual cup use led to an IUD becoming dislodged or coming out of the vagina in 13 participants (0.39% of the total number).
However, IUD expulsion naturally occurs in about one in 20 people, with or without the use of menstrual cups. It commonly occurs during a period, so it is not possible to confirm that the menstrual cup was the direct cause of expulsion.
A 2012 study found that the risk of IUD expulsion was no higher when people used tampons, pads, or menstrual cups.
However, people who use an IUD may wish to avoid menstrual cups if they are worried about the potential risk of expulsion.
The Lancet review did not find evidence that menstrual cups pose an increased risk of infection compared with other period products. Some of the included studies indicated that cups are less likely to cause infections than tampons or pads.
However, there is still a small risk of infection when using cups, which increases if a person does not keep their cup clean.
Toxic shock syndrome
Toxic shock syndrome (TSS) is a serious and potentially life threatening bacterial infection that a strain of Staphylococcus aureus causes. It is most commonly associated with tampons, but in very rare cases, it also occurs in people who use menstrual cups.
Some advocates for menstrual cups cite older research as proof that TSS only occurs when people use highly absorbent materials internally, such as those found in tampons. However, more recent research shows that TSS is possible in menstrual cup users too.
According to the authors of the review in The Lancet, the risk of TSS is low.
Compared with tampons and sanitary pads, menstrual cups are:
- reusable, which creates less waste
- convenient, as they can stay in the vagina for longer than tampons
- more cost effective than disposable products
- less likely to contribute to yeast infections and bacterial vaginosis, according to some studies
- potentially less likely to cause leaks once a person gets comfortable with using them
73% of menstrual cup users in The Lancet review wanted to continue using these products after the studies were over.
It can take more time to learn how to use menstrual cups. A person may need to try several cups before they find the right one for them.
Some people have difficulty using menstrual cups. In some cases, this is due to differences in anatomy or to conditions such as vaginismus, which causes pain when a person tries to insert items into the vagina. A gynecologist may be able to help with this issue.
People with severe vaginal injuries and those who have just given birth should not insert anything into the vagina.
Before using a menstrual cup for the first time:
- Find a cup that fits the body well and is neither too hard nor too soft.
- Sterilize the cup by adding it to a pot of clean, boiling water for 10 minutes.
- Alternatively, it is possible to purchase sterilization tablets, which can be useful when clean, hot water is not available.
- Wash the hands with soap and water.
To insert a menstrual cup:
- Wet the outside of the cup with water or apply water-based lubricant.
- Press the rim of the cup together so that it forms a straight line. Fold it in half so that the rim forms a “C” shape.
- Holding the cup in this shape, insert it rim-first into the vagina.
- Once inside, the cup should open up and form a seal around the vaginal wall. A person can test this by running their finger around the edge.
A person can wear the cup for 8–12 hours at a time. They should then empty it and rinse it out thoroughly before reinserting it again.
It is important never to wear a cup for longer than 12 hours at a time without emptying and washing it, even if it is not full.
To remove the menstrual cup:
- Wash the hands with soap and water.
- Carefully insert the fingers into the vagina and pull gently on the stem of the cup.
- When the bottom of the cup is within reach, pinch it to break the seal.
- Remove the cup and empty the contents into the toilet or sink.
After each period is over, a person should sterilize the cup again before storing it in a clean container until the next period. They should never share menstrual cups with others.
The term “virgin” describes someone who has not had penis-in-vagina sex. It is a social construct rather than a biological state.
Using a menstrual cup does not mean that a person has lost their virginity. However, these items can occasionally stretch open the hymen, which is a thin piece of tissue that some people have around their vaginal opening.
Even if a menstrual cup or tampon does stretch the hymen, this does not mean that a person is no longer a virgin.
Menstrual cups are safe to use, as long a person follows the safety guidelines. There is no evidence that they are any more dangerous than tampons.
Rarely, menstrual cups can cause pain, urinary problems, or infection. If this occurs, it is important to stop using the product and speak to a doctor or gynecologist.