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What Are You Putting Into Your Vagina? It's Time to Redefine Safety

In an era of over-sanitation and vaginal shaming, it’s important to consider what vaginal health and feminine hygiene products do not just to you but to your microbes.

6 minutes

22 Citations

The vaginal health industry is built on a foundation of taboo and shame, with many products promising to solve “problems” that aren’t problems at all. Vaginal odor, discharge, and pubic hair are natural features of having a vagina—not disgraceful issues that need to be fixed. Beyond being misguided, some feminine health products can be downright unsafe. 

Everything we put into our vaginas impacts our vaginal microbiome; sometimes in a way that can breed frustration, pain, and disease. Here’s a peek at how some ubiquitous vaginal health and feminine hygiene products affect your microbial landscape within.

Why Is the Vaginal Microbiome (VMB) so Important? 

The vaginal microbiome (VMB) is a complex ecosystem composed of bacteria, opportunistic fungi, and billions of microorganisms in between.1,2 

Until recently, our understanding of the structure and function of the vaginal microbiome was frustratingly rudimentary. VMB research is still fairly new—especially when compared to the study of the male anatomy—since women were largely excluded from clinical trials until the Women and Minorities as Subjects in Clinical Research law passed in 1993.3,4 Yep, researchers have been required to study the female anatomy in earnest for about as long as Pepsi Max and Jurassic Park have been around.

The more we (finally) learn about the vaginal microbiome, the more we see what a critical role it plays in health and disease. Most vaginal microbiomes are ruled by Lactobacillus species—a type of lactic acid-producing bacteria responsible for keeping the VMB moderately acidic (between 3.8 and 5.0 on the pH scale during reproductive years).1,5 It’s their job to help make it difficult for pathogens to multiply, spark infections, and cause inflammation or dysbiosis (a state in which the harmful bacteria outnumber the protective bacteria).1 As such, they appear to be instrumental in protecting us from a range of health complications, from recurring urinary tract infections to fertility challenges to unexplained itching and burning.6,7 

Here’s the thing about the composition of your vaginal microbiome, though: it’s flexible and constantly changing. Every time you insert something into the vagina, you add new microbes into the VMB to unknown effect. Think of it like planting a new species into a pine forest: it may go on to thrive in those conditions, it may die off quickly, or it may become invasive and outcompete with native plant life for nutrients. This is why it’s essential to consider not just what your products do for you, but what they do for your microbes. 

How Everyday Products Impact the VMB

Here’s the latest on how some vaginal health products seem to impact the VMB. This information isn’t meant to scare you or make you swear off menstrual pads (although it’s safe to say you can throw that intimate wash in the trash). Instead, we hope it empowers you to consider your microbiome when making purchasing decisions. Hopefully, as VMB research evolves, more companies will work the relatively nascent field of microbiome science into their products to make it easier for you.

Intimate washes 

Intimate washes, feminine deodorizers, douches… whatever you know them as, they’re unnecessary at best and harmful at worst.8 The vagina is a self-cleaning organ, and it can flush out any unwelcome pathogens (via vaginal discharge) with no help from us. When we get involved by using soaps or douches, we run the risk of increasing the pH of the VMB, setting the scene for pathogenic bacteria to repopulate and dominate.9 Remember: your vagina should smell like a vagina. Just because its odor doesn’t remind you of fresh laundry or rose gardens doesn’t make it dirty or in need of cleansing.


Lube can play a valuable role in a healthy and enjoyable sex life. However, some lubes contain ingredients that have a drying, dehydrating effect on the vaginal wall. Pre-clinical research has also found that some ingredients in lube (chlorhexidine gluconate is a top offender) can damage vaginal tissue and inhibit the growth of Lactobacillus species, though more studies conducted with humans are needed to confirm this risk.10,11

Intrauterine devices (IUDs) 

Some research suggests that copper IUDs can harbor inflammatory bacteria and reduce lactobacilli populations compared to other forms of contraception.12 One 2021 study published in Clinical Infectious Diseases found that among 2,585 African women ages 18 to 45, those who used a copper IUD were about 28% more likely to develop bacterial vaginosis (BV) than those who didn’t.13 But again, we need more research to be sure. 

Period products

Like lube, tampons, menstrual cups, and period underwear aren’t automatically “bad” for the vagina’s microbial environment. Very little research has been done on them, but so far, they do seem to alter vaginal microbiome composition (at least temporarily) and some might have a more disruptive impact than others.14 

Is one option better than the other?

The Isala project—a citizen science study of the vaginal microbiome of 3,043 participants in Belgium—found that the use of menstrual cups was positively associated with protective lactobacilli. Separate research found that after adolescent girls in Kenya used menstrual cups for 30 months, they had a VMB with more protective lactobacilli and were less likely to have developed BV. In the Isala project, menstrual pads were negatively associated with the beneficial species. Using a tampon was associated with a decrease in potentially harmful bacteria.

That said, using these products incorrectly has been associated with vaginal irritation and infection.  For example, if left in for longer than recommended, period products can harbor pathogenic bacteria like Staphylococcus aureus, which can fuel toxic shock syndrome (TSS).16 Many people associate TSS with tampons, but research suggests that it can happen with menstrual cups too. In fact, cups may be more likely to fuel S. aureus growth since they allow more oxygen into the vagina during insertion (potentially paving the way for oxygen-loving aerobic bacteria to multiply).17 

It’s also worth mentioning that investigations into period products have found that some contain phthalates, parabens, and PFAS (per- and polyfluoroalkyl substances)—persistent chemicals that are used to make heat-proof, water-proof, or grease-proof products and to make plastics more durable, among other things.18,19,20 These chemicals have endocrine-disrupting properties, and their long-term impact on human health (let alone, microbial health) is still unknown.19 Opt for products that are organic, hypoallergenic, and free of fragrances and dyes if you can. 


Many people with vaginas find themselves jumping from one infection to the next and back again, only to be told by their doctor, “Here’s your prescription, better luck next time.”21 This is because while antibiotics and antifungals can effectively kill dangerous pathogens in the VMB, they also strip it of beneficial bacteria. Just like you wouldn’t set fire to a pine forest to kill off a single invasive species, it doesn’t always make sense to use harsh antibiotics as a first line of defense in the VMB.

Vaginal probiotics

Vaginal probiotics promise to re-populate the VMB with beneficial bacteria. However, very few of them have actually been clinically studied for this purpose. 

It’s safe to say the development of vaginal probiotics has been lacking: lacking in care, lacking in creativity, and lacking in a robust understanding of microbial health. However, that’s starting to change. In innovative research initiatives like LUCA, a women’s health company that emerged from Seed Health’s foundry in 2019, researchers are testing thousands of samples to pinpoint the exact types (strains) of Lactobacillus that show the most promise for supporting a resilient and protective VMB. These can help inform probiotics that successfully deliver targeted strains to the vagina, in efficacious amounts.

The Future of Microbiome-Friendly Care

From feminine washes to tampons to menstrual cups, these days there’s no shortage of vaginal health products—and most of us don’t think twice before using them. However, research is increasingly finding that some of these products can negatively impact the fascinating but finicky landscape of the vaginal microbiome. Here’s hoping that the burgeoning world of VMB research brings a wave of new products that are designed not just for us, but for the microbes that compose nearly 50% of our bodies.22 


  1. France, M., Alizadeh, M., Brown, S. E., Ma, B., & Ravel, J. (2022). Towards a deeper understanding of the vaginal microbiota. Nature Microbiology, 7(3), 367–378.
  2. Willems, H. M. E., Ahmed, S. S., Liu, J., Xu, Z., & Peters, B. M. (2020). Vulvovaginal candidiasis: A current understanding and burning questions. Journal of Fungi (Basel, Switzerland), 6(1), 27.
  3. Ah-King, M., Barron, A. B., & Herberstein, M. E. (2014). Genital evolution: Why are females still understudied?. PLoS Biology, 12(5), e1001851.
  4. History of women’s participation in clinical research. (n.d.).,as%20Subjects%20in%20Clinical%20Research
  5. Lin, Y. P., Chen, W. C., Cheng, C. M., & Shen, C. J. (2021). Vaginal pH value for clinical diagnosis and treatment of common vaginitis. Diagnostics (Basel, Switzerland), 11(11), 1996.
  6. Stapleton A. E. (2016). The vaginal microbiota and urinary tract infection. Microbiology Spectrum, 4(6), 10.1128/microbiolspec.UTI-0025-2016.
  7. Ravel, J., Moreno, I., & Simón, C. (2021). Bacterial vaginosis and its association with infertility, endometritis, and pelvic inflammatory disease. American Journal of Obstetrics and Gynecology, 224(3), 251–257.
  8. Nicole W. (2014). A question for women’s health: Chemicals in feminine hygiene products and personal lubricants. Environmental Health Perspectives, 122(3), A70–A75.
  9. Chen, Y., Bruning, E., Rubino, J., & Eder, S. E. (2017). Role of female intimate hygiene in vulvovaginal health: Global hygiene practices and product usage. Women’s Health (London, England), 13(3), 58–67.
  10. Łaniewski, P., Owen, K. A., Khnanisho, M., Brotman, R. M., & Herbst-Kralovetz, M. M. (2020). Clinical and personal lubricants impact the growth of vaginal lactobacillus species and colonization of vaginal epithelial cells: An in vitro study. Sexually Transmitted Diseases, 48(1), 63–70.
  11. Ayehunie, S., Wang, Y. Y., Landry, T., Bogojevic, S., & Cone, R. A. (2017). Hyperosmolal vaginal lubricants markedly reduce epithelial barrier properties in a three-dimensional vaginal epithelium model. Toxicology Reports, 5, 134–140.
  12. Brown, B. P., Feng, C., Tanko, R. F., Jaumdally, S. Z., Bunjun, R., Dabee, S., Happel, A. U., Gasper, M., Nyangahu, D. D., Onono, M., Nair, G., Palanee-Phillips, T., Scoville, C. W., Heller, K., Baeten, J. M., Bosinger, S. E., Burgener, A., Passmore, J. S., Heffron, R., & Jaspan, H. B. (2023). Copper intrauterine device increases vaginal concentrations of inflammatory anaerobes and depletes lactobacilli compared to hormonal options in a randomized trial. Nature Communications, 14(1), 499.
  13. Peebles, K., Kiweewa, F. M., Palanee-Phillips, T., Chappell, C., Singh, D., Bunge, K. E., Naidoo, L., Makanani, B., Jeenarain, N., Reynolds, D., Hillier, S. L., Brown, E. R., Baeten, J. M., Balkus, J. E., & MTN-020/ASPIRE study team (2021). Elevated risk of bacterial vaginosis among users of the copper intrauterine device: A prospective longitudinal cohort study. Clinical infectious Diseases : An Official Publication of the Infectious Diseases Society of America, 73(3), 513–520.
  14. Lebeer, S., Ahannach, S., Gehrmann, T., Wittouck, S., Eilers, T., Oerlemans, E., Condori, S., Dillen, J., Spacova, I., Donck, L. V., Masquillier, C., Allonsius, C. N., Bron, P. A., Van Beeck, W., De Backer, C., Donders, G., & Verhoeven, V. (2023). A citizen-science-enabled catalogue of the vaginal microbiome and associated factors. Nature Microbiology, 8(11), 2183–2195.
  15. Mehta, S. D., Zulaika, G., Agingu, W., Nyothach, E., Bhaumik, R., Green, S. J., Van Eijk, A. M., Kwaro, D., Otieno, F., & Phillips-Howard, P. A. (2023). Analysis of bacterial vaginosis, the vaginal microbiome, and sexually transmitted infections following the provision of menstrual cups in Kenyan schools: Results of a nested study within a cluster randomized controlled trial. PLoS Medicine, 20(7), e1004258.
  16. Schlievert, P. M., & Davis, C. C. (2020). Device-associated menstrual toxic shock syndrome. Clinical Microbiology Reviews, 33(3), e00032-19.
  17. Nonfoux, L., Chiaruzzi, M., Badiou, C., Baude, J., Tristan, A., Thioulouse, J., Muller, D., Prigent-Combaret, C., & Lina, G. (2018). Impact of currently marketed tampons and menstrual cups on Staphylococcus aureus growth and toxic shock syndrome toxin 1 production in vitro. Applied and Environmental Microbiology, 84(12), e00351-18.
  18. Redd, N. (2023, August 10). We had 44 period and incontinence products tested for forever chemicals. Many were contaminated. Wirecutter: Reviews for the Real World.
  19. Marroquin, J., Kiomourtzoglou, M., Scranton, A., & Pollack, A. Z. (2023). Chemicals in menstrual products: A systematic review. BJOG, 131(5), 655–664.
  20. Perfluoroalkyl and polyfluoroalkyl substances (PFAS). (n.d.). National Institute of Environmental Health Sciences.,Growing%20numbers.
  21. Bradshaw, C. S., Morton, A., Hocking, J. S., Garland, S. M., Morris, M. B., Moss, L. M., Horvath, L. B., Kuzevska, I., & Fairley, C. K. (2006). High recurrence rates of bacterial vaginosis over the course of 12 months after oral metronidazole therapy and factors associated with recurrence. The Journal of Infectious Diseases, 193(11), 1478–1486.
  22. Sender, R., Fuchs, S., & Milo, R. (2016). Revised estimates for the number of human and bacteria cells in the body. PLoS Biology, 14(8), e1002533.