The scientific and medical communities are catching up to what those of us working in the reusable period care space have known for decades – menstrual discs are the best product to handle heavy menstrual periods over disposable pads or tampons. (1)
If you live with a heavy “soaked a tampon in half an hour and it’s spilling out onto your backup pad or period underwear” period there’s hope for you with discs and cups. A new study published August 2023 in the journal BMJ Sexual & Reproductive Health compared the absorbency of tampons, cups, pads, period underwear, and discs using real blood; menstrual discs came out as the winner.
…the actual absorbency of period products like disposable pads has not matched to the claimed absorbency on the label; saline is not absorbed in the same way as menstrual blood.
Researchers set out to help clinicians understand and quantify what is considered “heavy bleeding” definitions of which haven’t been updated in decades to reflect all period care options. Not only that, but the tests themselves have until now relied on saline solutions, rather than real or simulated blood, to establish those measurements. …the actual absorbency of period products like disposable pads has not matched to the claimed absorbency on the label; saline is not absorbed in the same way as menstrual blood.
What is “Heavy Menstrual Bleeding?” | How HMB is Identified by Healthcare Providers
The guidelines for diagnosing heavy menstrual bleeding (HMB) were set decades ago, called the pictorial bleeding assessment chart (PBAC). To help medical professionals quantify and diagnose HMB this guide is used to help translate a patient’s self-reported bleeding by analyzing how full and how often their pads or tampons needed to be changed. According to the PBAC a patient can be diagnosed with heavy menstrual bleeding if they need to change a pad or tampon more often than every two hours.
“Approximately 10–35% of women report heavy menstrual periods at some stage during their reproductive years, with 5% consulting a medical practitioner for investigation of HMB [1]. In research, HMB is defined as a measured menstrual blood loss (MBL) of > 80 mL per cycle, but studies have repeatedly shown that at least 40% of women seeking medical attention for heavy periods lose less than this volume.” (3)
Heavy bleeding is often caused by underlying medical conditions that are either ignored, dismissed, or downplayed when those suffering try to explain their symptoms. Add to that the outdated methods of diagnosing HMB and it’s no wonder reproductive disorders like PCOS, Endometriosis, and Fibroids have a delayed diagnosis.
What is harder to quantify is what level of absorbency the patient is using and if each brand absorbs the same even within matching categories such as “ultra” or “super.” These guidelines also lack the real lived experience of users who may change products more often for comfort, or less often due to lack of finances in order to use fewer items.
According to another study published earlier this year, the PBAC and other methods “… fail to capture the current diversity in the menstrual hygiene market, leaving out people who use alternative items such as menstrual cups, menstrual discs, menstrual underwear, or multiple methods.” (2)
Background of Period Product Absorbency Testing and Advertising
If you’ve ever seen a period product ad that uses watery liquids, either blue or red in color, to showcase their absorbent properties the immediate response mentally is usually – “but blood is thick, it’s clotty, it’s NOT WATER.” Not only does using water or saline to test product absorbency inaccurate when it comes to how much blood it can absorb, other crucial parts of the lived experience of period-havers is left out – speed of absorbency when having a flood-like period – and the experience of passing clots.
Cup and disc users are especially aware of the true nature of menstrual blood and how viscous, sometimes topped with a watery clear liquid (person and time of cycle-dependent) the fluid is as contained inside a cup or disc. New users often share how fascinating it was the first time they removed their cup because they were finally able to see their actual menstrual blood not absorbed into a product. The menstrual fluid may also include jelly-like clots, made of coagulated blood and tissue, that usually sit atop pads or period underwear but are collected into a cup or disc.
Absorbency Testing and Standardization Background – Tampons Are Standardized But Other Products Are Not
Until the TSS scare of the 1980s tampon absorbency testing was not standardized and each brand used various terms to describe how absorbent their products were. A “Tampon Task Force” was assembled, which included major brands of tampon manufacturers alongside members of women’s issues consumer groups.
“Menstrual flow rates are anything but consistent, changing from the start to the end of a period, with actual menstrual fluid ranging from thin and watery to globular blood clots. What would it mean for the standard to be based upon a saline solution rather than real-life conditions of blood, mucus and the biological debris of menses? This was not being investigated by the corporate researchers. Expedience trumped these concerns, with ignorance at best and sexism at worst influencing scientific practice.” (4)
Nancy King Reame, a multi-disciplinary researcher and member of the Society for Menstrual Cycle Research Society, played a key role in tampon absorbency tests. I had the pleasure of hearing about her work when we met in DC last month so she immediately came to mind when this study was published. Reame pushed for more accurate solutions other than saline and pioneered alternative absorbency test methods which included the collection of real blood using Tassaway menstrual cups.
“I recruited labor and delivery nurses to collect their own menstrual blood using a menstrual cup, which seemed totally reasonable and natural for us as women and nurses, and borrowed a paint viscosity machine from a physics lab down the hall to assess viscosity as well as other properties. That same year, the FDA task force was convened, and I served as the testing lab for the consumer advocates on the committee. We used outdated heparinized blood from the hospital blood bank and compared tampon absorbency to the standard test fluid (blue-dyed saline) in a testing device used by the FDA and the tampon producers called a “syngyna”. We named ours “Sally”! All along the way, I was told by the tampon industry reps that it wouldn’t work – that the blood was too viscous and would clog up the machine – but it did! These data demonstrated marked differences in tampon absorbency across brands and absorbency categories which ultimately helped support the change in tampon absorbency labeling on all products, still in effect today.” She goes on to say “As the lab representative for the consumer advocates on the FDA task force in the 80s, we showed that using blue dyed saline was totally inadequate for testing the absorbency of tampons in the laboratory, underestimating absorbency when compared to human de-clotted venous blood… the “blue goo” wasn’t anywhere near the correct consistency!” (5)
Tampon absorbency wasn’t fully standardized until the 1990s, only done after public pressure on the FDA and following a lawsuit. (4) The Syngyna is a synthetic vagina designed to simulate a real vaginal environment in the temperature, pressure, and flow output for the purposes of the standardized absorbency rating of tampons, still used today.
After 1990, tampon packages had to display a specific set of ranges and use this accompanying language: 6 g or less (junior absorbency), greater than 6 g up to and including 9 g (regular absorbency), greater than 9 g up to and including 12 g (super absorbency) or greater than 12 g up to and including 15 g (super plus absorbency). (4)
Between the 1980s and 2023, almost nothing has changed in the way we measure product absorbency. Not only that, but new products that are increasing in use among those with periods such as menstrual cups, discs, and period underwear have been left out of the discussion.
Other absorbent products, like pads, and the newer product period underwear lack those requirements which means their claimed absorbency on the package or product listing can vary wildly in either direction from their true absorbency. The FDA does not regulate a testing method or standards for pads or period underwear absorption when worn, in the way a synthetic vagina and saline is used to facilitate absorbency tests for tampons. Manufacturers have ways of testing their own products – for example, Kimberly Clark uses a patented synthetic menstrual blood recipe. Each put products through their own tests while developing them.
Between the 1980s and 2023, almost nothing has changed in the way we measure product absorbency. Not only that, but new products that are increasing in use among those with periods such as menstrual cups, discs, and period underwear have been left out of the discussion.
The Methods | Using Blood Cells Instead of Saline Water to Test Period Product Absorbency
In this study, researchers used red blood cells instead of saline to test the absorbency of each disposable product. “The researchers used expired packed blood cells, the bagged kind found in blood banks, which are just red blood cells separated from whole blood. Neither form is really the same as menstrual blood, which also includes endometrial cells and vaginal secretions, but it is better than just using water or saline.” – menstrual fluid is more than just blood, it also contains vaginal secretions and the endometrial cells of the uterine wall.
For tampons, containers were each filled with 50mL of red blood cells and then each tampon was placed in its own container. Tampons remained in each container until the blood reached the wick of the tampon or 30 min elapsed, whichever occurred first. This study did not use the syngina.
For pads and period underwear, red blood cells were poured slowly over the central upper third of the pad/underwear until the item no longer absorbed the blood and the blood either pooled or ran off the item.
For menstrual cups and discs the products were filled and held level to determine how much each product would hold without spilling. (1)
The Products Tested | Tampons, Pads, Cups, Discs, and Period Underwear
Out of the thousands of available models and products available in the US alone this study tested 21 individual products – for tampons only 1 brand is represented, for cups only 1 brand, for discs 4 brands were tested.
Out of the thousands of available models and products available in the US alone this study tested 21 individual products – for tampons only 1 brand is represented, for cups only 1 brand, for discs 4 brands were tested.
For tampons, the only brand used was Tampax Pearl Regular, super, and super plus. For disposable pads, U by Kotex Lightdays plus with Comfortflex design Regular, U by Kotex Security Maxi Pad Heavy, Always Ultra Long with wings Size 2, Always Ultra Night – Night with wings Size 3, Postpartum pad (Medichoice OB Peach Pad) OB Peach Pad 7” x 14”, and Cardinal Health Perineal Cold Pack.
For menstrual cups the only brand used was DivaCup in Model 0, Model 1, and Model 2. For menstrual discs the brands used were Intimina – Ziggy Cup Size B (formerly known as their One Size), Moonthlies menstrual disc Small and Large, Lumma menstrual disc Medium, and Flex menstrual disc (disposable version).
Only one brand was used for period underwear, Knix Super Absorbency in sizes S, M, L. Cloth pads were not part of this study.
The average absorbed by the tampons in this study came to 28.3 mL. For pads, the absorbencies varied wildly by brand and their purported absorbency level. Using the study’s findings (table 2) the average absorbency for pads was 24 mL, I excluded their post-partum and cold pack pad products which are more of a specialty item and not used for a regular period by most to arrive at this average.
Blood is Thicker Than Water | Are We Being Lied to About Period Product Absorbency?
@luna_cosmia What in the Reese’s peanut butter f*ck?
♬ original sound – nat
The reaction to this study on social media has been huge. People are sharing strong emotional responses to learning that only this year has research been conducted using multiple products with real blood instead of saline. This news has caused an outcry of betrayal. Women and people with periods feel they have been misled or intentionally deceived about the absorbency of the products they use.
I am going to be angry about the period product testing thing for approximately the rest of my life. I hope y’all all are prepared for that.
— madeline odent (@oldenoughtosay) August 14, 2023
While it does seem counterintuitive, at least in the case of tampons, the saline tests versus the blood tests show that tampons absorb MORE blood than saline, not less. I also assumed the opposite would be true. The reactions online have overwhelmingly interpreted this study to mean that all pads and tampons are underreporting their absorbency levels. I’d say it’s far more complicated. If anything, this study is highlighting the lack of standards across the period products industry and how behind the research is when it comes to including alternative products. Yes, this does mean some brands label their products are absorbing or collecting more than they do. But it also means products, specifically tampons which are using saline and standardized tests, may hold more than their labels say.
I reached out to the co-author, Bethany Bannow, to clarify the intent and results of this study in regards to the listed absorbency on product packages (by disposable brands) as well as how their tests compared to the previous tests using blood done in the 1980s, and what impact this study might have.
“The purpose of the study was to estimate how much blood modern period products can contain to better understand blood loss in patients who report frequency of saturating different products.
…tampons may very well absorb more blood than saline (and I believe that is what Nancy Reame found as well). While we didn’t record reported absorption from companies (I don’t believe volume was listed on the packaging) the maximum amount of fluid a tampon should theoretically hold is 15-18 mL and all our tampons absorbed more than that.”
Bethany Bannow, Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA (10)
The point of the study was to help clinicians update their understanding of what heavy menstrual bleeding looks like in all varieties of menstrual devices. Instead, this study unknowingly opened the door to a wider conversation about the transparency, accuracy, and lack of research being done in the period product space. According to Statnews and a search through PubMed, erectile dysfunction is overrepresented in published medical research compared to periods, with a 25:1 ratio of papers on ED compared to periods during the years 2011 through 2018. (9)
The Conclusion | Menstrual Discs and Cups Collect More Blood Than Tampons, Pads, or Period Underwear
The study only relied on one brand of menstrual cup, the DivaCup, in 3 sizes. The average capacity of those 3 cups came to 27.3 mL. For discs, the study used a slightly more diverse set of brands bringing the average absorbency of this category to 61.4 mL. (table 2)
Expanding on the set used by the study utilizing Period Nirvana’s comprehensive resources there are a total of 183 menstrual cups in our database and 28 menstrual discs. Based on the listed capacity of these products an average capacity for each product type was calculated.
The average menstrual cup capacity is 27.7 mL. This spans all sizes of menstrual cup products ranging from the lowest, 8 mL, to the highest, 51 mL. The average capacity of discs is 52.1 mL which spans all sizes of menstrual disc products ranging from the lowest, 30 mL, to the highest, 79 mL. Due to the design of these products and how they collect, rather than absorb, it’s easy to accurately measure how much they can hold in comparison to products that absorb.
The average menstrual cup capacity is 27.7 mL. This spans all sizes of menstrual cup products ranging from the lowest, 8 mL, to the highest, 51 mL. The average capacity of discs is 52.1 mL which spans all sizes of menstrual disc products ranging from the lowest, 30 mL, to the highest, 79 mL. Due to the design of these products and how they collect, rather than absorb, it’s easy to accurately measure how much they can hold in comparison to products that absorb.
That said, the way a product is worn in the body can affect the actual capacity in the body. A cup may lose capacity when a cervix dips into the cup. A disc likely holds less than what it can collect to the rim when held upright “under a faucet” due to how it’s worn at an angle in the body. The methods of accurately determining how much the disc holds when in the body haven’t been figured out.
The study found period underwear to be the least absorbent however their sample was very small and only represented one brand. As mentioned above, that number is also likely lower based on the method the underwear were tested; via droplets without pressure. Marketing of period underwear lists the absorbency as much higher than the average of 1 mL (table 2).
“Cups and discs held as much as—if not more than— period underwear and many disposable products.”
BMJ Study findings
“Cups and discs held as much as—if not more than— period underwear and many disposable products.” (1) No matter how you slice it when you look at this study, and Period Nirvana’s own averages based on listed capacities, menstrual discs win out over all other products. Even when taking the loss of volume of menstrual discs when worn in the body based on their positioning, a number hard to quantify, the disc is still the product with the highest absorbency/capacity available for period havers.
Real-Life Implications of Saline Absorbency Tests Versus Red Blood Cells (real blood)
The study highlights one aspect of medically heavy periods that is hard to measure in a lab – the rate of your flow and the speed of absorbency for each product. In period product ads and demonstrations the rate of absorbency is often sped up with a disclaimer in small letters, or, it is not but the liquid in use is a dyed water or saline that absorbs faster than real menstrual fluid.
“This study also demonstrated that period underwear, despite being advertised to hold many tampons worth of blood, absorbed only a very small amount of blood and quite slowly—suggesting that this is unlikely to be the menstrual product of choice for patients with ‘flooding’, or passage of clots, clinical features predictive of heavy bleeding. This is consistent with our clinical experience in which we find few, if any, patients with HMB utilise period underwear. Those that do, often use it as a ‘backup method’ under a pad or with an internal product (tampon, cup, disc), or on the lighter days when the ‘flooding’ episodes characteristic of HMB are less likely to occur.” (1)
This study also did not take into consideration where the bleeding came from – such as the top of the tampon (like in actual use) all over the tampon, or like in pads when standing versus laying down to sleep. The use of the syngina in conjuction with the expired red clood cells would likely have made these numbers more accurate. The period underwear testing method lacked the pressure applied during wear that is needed for the menstrual fluid to absorb faster, negatively impacting the true absorbency numbers that I suspect would have been higher. Still, the lived experience does align with the idea that only using period underwear for heavy menstrual bleeding is unlikely to be sufficient, but they do make great backups for peace of mind in conjunction with tampons, cups, or discs.
The advantage of cups and discs in real life is that they absorb (collect) the same no matter your position as long as the product is placed properly (sealed) and is the right fit for the user.
There is another study already in progress investigating the use of menstrual cups and period underwear by users with heavy periods due out later this year which should more accurately assess the real-life absorbency abilities of the underwear.
The advantage of cups and discs in real life is that they absorb (collect) the same no matter your position as long as the product is placed properly (sealed) and is the right fit for the user.
Selfishly, I am grateful the research brings cups and discs into the fold because this is how more medical professionals will be made aware of their existence. Somehow, despite 15.5% of users relying on alternative products such as menstrual cups, menstrual discs, menstrual underwear or reusable pads, many medical professionals are still undereducated on all aspects of their use. (8)
Heavy bleeding significantly affects the lives of those who live with it. This study proves that a menstrual disc is a very effective product to use. Personal testimonials I receive report that discs can give users several hours of additional wear time. Going further, the lived experience of people with heavy periods who prefer menstrual discs cite their “self-emptying” function as a critical reason why they use a disc.
In a clinical setting, an updated reference source for how much each period product holds for the purpose of diagnosing HMB (heavy menstrual bleeding) that includes cups, discs, and period underwear is a step in the right direction. More people use these products so studies should utilize them now and going forward in every study that involves period products.
Heavy bleeding significantly affects the lives of those who live with it. This study proves that a menstrual disc is a very effective product to use. Personal testimonials I receive report that discs can give users several hours of additional wear time. Going further, the lived experience of people with heavy periods who prefer menstrual discs cite their “self-emptying” function as a critical reason why they use a disc.
If you suspect you have a heavy period it’s important to communicate this to your healthcare provider but higher capacity products in addition to potential treatments can often help people live better lives while managing their HMB. Just read through the comments on this Instagram post and you can see how many people self-selected discs as a way to help managed their heavy periods. And the use of products like menstrual cups or discs helps to quantity your blood loss each cycle.
Sources:
(1) DeLoughery E, Colwill AC, Edelman A, et al Red blood cell capacity of modern menstrual products: considerations for assessing heavy menstrual bleeding BMJ Sexual & Reproductive Health Published Online First: 07 August 2023. doi: 10.1136/bmjsrh-2023-201895 https://srh.bmj.com/content/early/2023/07/03/bmjsrh-2023-201895
(2) Liberty, Abigail MD, MSPH; Samuelson Bannow, Bethany MD; Matteson, Kristen MD, MPH; Edelman, Alison MD, MPH; Colwill, Alyssa MD, MCR. Menstrual Technology Innovations and the Implications for Heavy Menstrual Bleeding. Obstetrics & Gynecology 141(4):p 666-673, April 2023. | DOI: 10.1097/AOG.0000000000005126 https://journals.lww.com/greenjournal/fulltext/2023/04000/menstrual_technology_innovations_and_the.6.aspx
(3) Magnay JL, O’Brien S, Gerlinger C, Seitz C. Pictorial methods to assess heavy menstrual bleeding in research and clinical practice: a systematic literature review. BMC Womens Health. 2020 Feb 10;20(1):24. doi: 10.1186/s12905-020-0887-y. PMID: 32041594; PMCID: PMC7011238.
(4) Vostral S. Toxic shock syndrome, tampons and laboratory standard-setting. CMAJ. 2017 May 23;189(20):E726-E728. doi: 10.1503/cmaj.161479. PMID: 28536130; PMCID: PMC5436965. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5436965/
(5) Pichon, Adrienne. Menstrual Spotlight: Meet faculty fellow Nancy Reame! 2019 February 1; https://periodsatcolumbia.com/2019/02/01/menstrual-spotlight-meet-faculty-fellow-nancy-reame/
(6) Reame NK. Toxic Shock Syndrome and Tampons: The Birth of a Movement and a Research ‘Vagenda’. 2020 Jul 25. In: Bobel C, Winkler IT, Fahs B, et al., editors. The Palgrave Handbook of Critical Menstruation Studies [Internet]. Singapore: Palgrave Macmillan; 2020. Fig. 51.2, [The Syngina test instrument: The industry standard for measuring tampon absorbency]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK565591/figure/ch51.Fig2/ doi: 10.1007/978-981-15-0614-7_51 https://www.ncbi.nlm.nih.gov/books/NBK565591/figure/ch51.Fig2/
(7) Chloé Parent, Camille Tetu, Coralie Barbe, Stéphanie Bonneau, René Gabriel, Olivier Graesslin, Emilie Raimond, Menstrual hygiene products: A practice evaluation, Journal of Gynecology Obstetrics and Human Reproduction, Volume 51, Issue 1, 2022, 102261, ISSN 2468-7847, https://doi.org/10.1016/j.jogoh.2021.102261.
https://www.sciencedirect.com/science/article/abs/pii/S2468784721001987?via%3Dihub
(8) Chloé Parent, Camille Tetu, Coralie Barbe, Stéphanie Bonneau, René Gabriel, Olivier Graesslin, Emilie Raimond, Menstrual hygiene products: A practice evaluation, Journal of Gynecology Obstetrics and Human Reproduction, Volume 51, Issue 1, 2022, 102261, ISSN 2468-7847, https://doi.org/10.1016/j.jogoh.2021.102261.
(https://www.sciencedirect.com/science/article/pii/S2468784721001987)
(9) Balthazar, Deborah, A new study put period products through the wringer. Discs came out a winner, 2023, August 7; Stat News, https://www.statnews.com/2023/08/07/period-products-menstrual-disc-new-study/
(10) Bannow, Bethany, email correspondence, 2023, August 16; Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA
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