The Menstrual Cup and Toxic Shock Syndrome

May 14, 2018
menstrual cup and toxic shock syndrome, tss menstrual cup, toxic shock syndrome, toronto naturopath, naturopathic doctor toronto

Ask Alexsia: Can menstrual cups cause toxic shock syndrome?

Since switching to a menstrual cup years ago, I commonly get asked if toxic shock syndrome (TSS) is still a concern (spoiler alert: yes!).

How does toxic shock syndrome happen?

TSS is a rare, but severe disease. It commonly happens when tampons or menstrual cups cause the vaginal canal to colonized by Staph aureus, which produce a toxin called TSST-1. Toxic shock was first seen in women who used tampons made of high-absorbency fibres favouring the growth of Staph aureus and TSST-1 production 

Symptoms of TSS include: fever, hypotension (low blood pressure), a skin rash with subsequent peeling, and multiple organ dysfunctions.

Research on Menstrual Cups

Three reasons have been suggested to explain why bacteria grows:

  1. Accumulation of blood

  2. Increase of vaginal pH during menstruation from 4.2 to 7.4

  3. Oxygen and carbon dioxide are both present in the vagina during menstruation 

Few studies exist in relation to menstrual cups and TSS, but they have all come to the same conclusion that while menstrual cups do not absorb blood, they still put women at risk for TSS.

Many cups are made with medical-grade silicone. While silicone does not support bacterial growth, because of blood accumulation, menstrual cups provide a medium for bacterial growth. 

According to one study, because Staph aureus can form a biofilm (bacteria sticking to the surface of the cup), bacteria may be resistant to water. Therefore, it has been recommended to have 2 cups on hand during the menstrual cycle, and to boil them in water in between uses. 

Final Thoughts

At the end of the day, I’m still sticking with my beloved menstrual cup. I like using them because I can keep track of my monthly blood loss, I always forget to buy pads and tampons, and I don’t like the waste associated with the disposable options!

Therefore, you still want to be cautious when using a cup. As mentioned above, think about purchasing 2, boiling between use, and most importantly – not forgetting about it! 


Nonfoux L, Chiaruzzi M, Badiou C et al. Impact of currently marketed tampons and menstrual cups on Staphylococcus aureus growth and TSST-1 production in vitro. Appl Environ Microbiol. 2018:AEM.00351-18. doi:10.1128/aem.00351-18.

Juma J, Nyothach E, Laserson K et al. Examining the safety of menstrual cups among rural primary school girls in western Kenya: observational studies nested in a randomised controlled feasibility study. BMJ Open. 2017;7(4):e015429. doi:10.1136/bmjopen-2016-015429.

Mitchell M, Bisch S, Arntfield S, Hosseini-Moghaddam S. A Confirmed Case of Toxic Shock Syndrome Associated with the Use of a Menstrual Cup. Canadian Journal of Infectious Diseases and Medical Microbiology. 2015;26(4):218-220. doi:10.1155/2015/560959.

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