Are Reusable Menstrual Products Safe for Patients?

Clinicians should know how to counsel patients on the safe use of more recent innovations in period products, such as menstrual cups, disks, and reusable period underwear.

Issues with reusable menstrual products are rare, and while research is slim, data have shown they are as safe as disposable pads and tampons. A handful of case studies have documented women who have experienced kidney and ureter inflammation and toxic shock syndrome from improper use, with the latest published in February in BMJ Case Reports.

Clinicians should consider a poorly placed menstrual cup if a patient reports using one and presents with discomfort or pain, said Clara Maarup Prip, MD, a physician in the Department of Urology at Aarhus University Hospital in Aarhus, Denmark, and a co-author of the recent case report.

“It is important that physicians make a possible connection between the symptoms and the menstrual product,” Prip said.

Prip and her colleague reported caring for a woman in her early 30s who complained of blood in her urine and pain in her right flank, which had been coming and going for 6 months. She did not have a fever or other lower urinary tract symptoms. A CT scan revealed swelling in her right kidney and the edges of an ill-placed menstrual cup compressing a swollen ureter.

After doctors removed the cup, the woman’s symptoms dissipated and her swelling quelled within a month. Within 6 months, she was back to normal and had used the cup again without issue.

Other case reports include a 2018 incident in which a poorly-placed menstrual cup caused renal colic; another from 2019 linked cup usage to a case of hydronephrosis in a 47-year-old woman.

In all three reports, researchers stressed the importance of patients and their providers gaining a better understanding of how to properly use newer period products.

“One thing all physicians and women would benefit from is understanding the female anatomy a little more intricately,” said Bethany Bannow, MD, an associate professor of medicine at Oregon Health & Science University School of Medicine in Portland, Oregon, whose research is aimed at helping clinicians understand patient experiences with menstruation. “Helping people understand that anatomy and where it’s supposed to go and how [a menstrual cup] is supposed to fit is going to go a long way.”

Menstrual cups are flexible and bell-shaped, usually made from rubber or silicone. The cup is folded, inserted into the vagina, and unfolds just below the cervix to catch menstrual blood much like a tampon does. Menstrual disks, which are dome-shaped, work in the same way but are usually shallower than cups. Reusable period underwear works like a pad, soaking up blood and capturing it in an absorbent material that can be washed and reused.

People choose reusable products over traditional pads and tampons for many reasons, said Gabrielle Whitmore, MD, an assistant professor and minimally invasive gynecologic surgeon at the University of Colorado Anschutz Medical Campus in Aurora, Colorado. Some prefer using the products because they create less waste. Others appreciate that menstrual cups can usually be left in for more hours than a tampon and hold more blood.

Give an Anatomy Lesson

A 2019 meta-analysis published in The Lancet Public Health reviewed 43 studies on the safety of menstrual cups involving more than 3300 people. The adverse events women reported were rare and not serious. Six people –– 0.18% of patients –– experienced an allergic reaction or rash. Nine, or 0.27%, reported urinary symptoms, including three who developed hydronephrosis linked to misplacement of the devices.

“Overall, complications of these cups are really pretty low,” Whitmore said.

Pain after inserting a menstrual cup is likely due to either not being the right size for an individual or not being positioned correctly, which could cause the cup to compress the ureters, Whitmore said.

Even inserting the right size could cause tearing, which can be remedied by using a lubricant, Whitmore said. However, she warns her patients not to use a silicone-based lubricant because doing so can cause the material to break down if the cup is made of the same material. Some cups or disks may be latex, which is important to note if a patient has an allergy.

Bannow recommends pointing patients to trustworthy online resources such as Period Nirvana, which can help patients find the best reusable period products for their body.

“People are going to go on their phones and on the internet trying to find information,” she said.

Intrauterine Device (IUD) Expulsion Does Happen

In the Lancet study, 13 people, 0.39%, reported a cup dislodged their IUD. More research is needed to determine how often IUD expulsion happens because of using menstrual products.

“That is not a common thing, but we are talking about a rare event to begin with,” Bannow said, referencing adverse events linked to menstrual cups.

A menstrual cup can dislodge an IUD through suction. Or the IUD string can accidentally be pulled out during removal of the cup. Whitmore said a heavy menstrual flow alone can dislodge an IUD.

A meta-analysis published in 2023 reported IUD expulsion among people who used menstrual cups from 3.7% to 18.6%. However, the studies reached different conclusions about how significant a role menstrual cups played. Between 2% and 10% of women who have an IUD experience expulsion, according to the American College of Obstetricians and Gynecologists.

Whitmore said patients cannot do much to avoid expulsion.

“The only thing is maybe asking your gynecologist to trim the strings a bit shorter, which may be more difficult to remove when the time comes.”

Infection Risk Low

The Lancet study did not find evidence that using a menstrual cup increased the risk for urinary tract or yeast infections. Few studies have been published on the subject, but some found lower rates of vaginal infections among menstrual cup users than those who used pads or tampons. One such study published in BMJ Open found women who used a menstrual cup had lower rates of bacterial vaginosis than those who used pads.

Both Whitmore and Bannow said the best way for patients to avoid infection is to wash their hands with soap and water before inserting or removing devices. Whitmore suggested telling patients to think about all the bacteria touched when using a phone or door handle.

The cups must be sanitized, usually boiled, at least once per cycle, Bannow said. She said she tells her patients to read the packaging and follow the manufacturer’s directions for how they should sanitize their menstrual product.

A few case reports linked toxic shock syndrome with using a menstrual cup, but the risk appears to be about the same as that of tampons, which is about two in every 100,000 menstruating women. Research suggests women who keep a tampon in for more than 6 hours are at greater risk. The US Food and Drug Administration recommends using the lowest absorbency tampon possible and changing it every 4-6 hours.

“In terms of when I think of scary things that can happen with period products, toxic shock is still front of mind,” Bannow said.

The data on risks related to reusable menstrual underwear are even sparser than data on menstrual cups. Reusable underwear is made of super-absorbent material that catches menstrual blood and can be washed and worn again.

Whitmore said an ill-fitting pair that does not have enough capacity for a woman’s flow could potentially irritate the skin or cause a yeast or urinary tract infection.

“At minimum, change every 12 hours, but every period underwear has a different capacity, so people need to be sure to match their flow,” Bannow said. “If they are filling up their underwear too quickly, it may be time to upsize.”

Whitmore said she also tells her patients to look for specific brands of period underwear without per and polyfluoroalkyl substance chemicals. An investigation by a UK watchdog group found high amounts of silver nanoparticles, an antibacterial agent, in certain brands of period underwear. Some research has shown these particles can easily kill healthy bacteria. But what effect wearing underwear embedded with these particles has on the vaginal microbiome is unclear.

An Opportunity to Dig Deeper

Whitmore said some of her patients prefer menstrual cups over tampons because they hold more blood. Some use period underwear as an insurance policy along with a pad, tampon, or menstrual cup. Others have not been able to stand the pain of inserting a cup or tampon.

“If you can’t walk to the door and back, if it’s too uncomfortable, take it out and try it again to make sure it’s in the right position. People shouldn’t feel them once they are in,” Whitmore said.

If a patient says they cannot stand the pain of inserting a period product of any kind, clinicians should take this as a warning sign of a potential larger issue.

“I’ve had many patients who have vaginal septums who have said, ‘I can’t use tampons,’ and we look and I say ‘yeah, there is an anatomical reason for that,’” Whitmore said. “Some pelvic floor muscles are so tight that maybe a cup or disk isn’t the right product for them.”

On the same note, if a patient has a particularly heavy period, “check to make sure we aren’t missing an underlying cause,” Whitmore said.

While some adverse events do occur, current data show that newer reusable period products are no less safe than disposable pads and tampons.

“Things are case reports because they are rare by definition,” Bannow said.

Kaitlin Sullivan is a freelance journalist.