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.

The Microbiome and Birth Control

April 30, 2018
microbiome and birth control, toronto naturopath, naturopathic doctor toronto, yeast infections, UTI, candida, bacterial vaginosis

The vaginal microbiome is becoming increasingly popular nowadays, and so I wanted to explore the relationship between it and hormonal birth control. I wanted to investigate if being on a form of hormonal contraception increased the risk of getting a vaginal infection. All the studies that I looked at ranged between 2014 and 2018, and looked at a variety of birth control options including combined oral contraceptive pills, progestin-only pills, the depo shot, copper IUD, and mirena IUS.  

Types of Birth Control

Combined Oral Contraceptives 

In one study, there were more hydrogen peroxide producing lactobacilli, and less BV-associated bacteria compared to condom users. 

Progestin-Only Pills

Women taking progestin-only pills, in one study, seemed to readily develop aerobic vaginitis (aka. abnormal flora) and vaginal atrophy (aka. thinning, drying, and inflammation of the vaginal walls). However, compared to Mirena users, women taking Mirena has a less likelihood of getting a candida infection. In fact, another study showed that women with a recurrence of vulvovaginal candidiasis should take progestin-only pills instead of intrauterine contraception. 

    Depo Provera Shot

    One study showed that a proportion of women with the Depo provera shot, had more Lactobacillus-dominated vagitypes than compared to condom users.

    Copper IUD

    According to a few studies, there was an asymptomatic prevalence of bacterial vaginosis in women with the copper IUD. One study looked at the time in which women began using this form of contraception, and BV prevalence continued to increase 6 months after the IUD was inserted. Moreover, another study showed that in women with the copper IUD, there was a trend towards BV, abnormal flora, increased pH (remember vaginal pH is about 3.8-4.5) and candida infections. 

    Mirena IUS

    There are mixed accounts of how Mirena affects the vaginal microbiome. In one study compared to the combined contraceptive pill, there were greater amounts of BV-associated bacteria in women with the Mirena device. This study indicated that Mirena may have a negative effect on the vaginal microbiome. With respect to Candida, women using Mirena has a higher risk of Candida compared to women not using any form of contraception.

    Two other studies said that compared to copper IUD users, long-term Mirena users had a lower risk of abnormal microflora,  and that the vaginal microbiome changes very little in response to Mirena. 

    Lastly a final study found a found a temporary worsening in lactobacilli and increased rates of BV after 3 months of Mirena use (compared to pre-insertion). However, after 1 and 5 years, the flora changes were reversed. Ultimately, there was a complete restoration to pre-insertion levels. However, candida increased significantly after long-term Mirena (when compared to pre-insertion).

    Final Thoughts

    Depending on the type of birth control you’re using, it’s important to be aware of any potential effects it may have on your vaginal microbiome. Moreover, if you find yourself getting constant infections – one of the causes may be the type of birth control you’re using! In that case, it may be best to start taking a vaginal probiotic and immune support, all under the supervision of a Naturopathic Doctor


    Brooks J, Edwards D, Blithe D et al. Effects of combined oral contraceptives, depot medroxyprogesterone acetate and the levonorgestrel-releasing intrauterine system on the vaginal microbiome. Contraception. 2017;95(4):405-413. doi:10.1016/j.contraception.2016.11.006.

    Achilles S, Austin M, Meyn L, Mhlanga F, Chirenje Z, Hillier S. Impact of contraceptive initiation on vaginal microbiota. Am J Obstet Gynecol. 2018. doi:10.1016/j.ajog.2018.02.017.

    Donders G, Bellen G, Janssens D, Van Bulck B, Hinoul P, Verguts J. Influence of contraceptive choice on vaginal bacterial and fungal microflora. European Journal of Clinical Microbiology & Infectious Diseases. 2017;36(1):43-48. doi:10.1007/s10096-016-2768-8.

    Jacobson J, Turok D, Dermish A, Nygaard I, Settles M. Vaginal microbiome changes with levonorgestrel intrauterine system placement. Contraception. 2014;90(2):130-135. doi:10.1016/j.contraception.2014.04.006.

    Donders G, Bellen G, Ruban K, Van Bulck B. Short- and long-term influence of the levonorgestrel-releasing intrauterine system (Mirena®) on vaginal microbiota and Candida. J Med Microbiol. 2018;67(3):308-313. doi:10.1099/jmm.0.000657.