Period Product Absorbency Study Uses Blood. For the First Time!

Period Product Absorbency Study Uses Blood. For the First Time!

Posted by Team joni on

The Department of Medicine at the Oregon Health & Science University recently studied period product absorbency using blood for the first time—instead of water or saline. While many were shocked to learn this hadn’t been done before, others were downright outraged.


It seems ludicrous that manufacturers haven’t been testing with the substance it is purportedly made for. In addition, the study revealed a discrepancy between reported absorption and actual blood absorption, which may affect how heavy menstrual bleeding (HMB) is diagnosed.


But wait.

While testing menstrual products using blood seems logical, it is tricky for a number of reasons, including practical considerations, testing accuracy, safety, and ethics. While saline has a purpose for certain testing scenarios, there are other synthetic options available that are more accurate than the blood used in this study.

Having said that, any scientific study into women’s health and menstrual health specifically is valuable because there is still so much work to be done in this traditionally neglected field. By testing with blood for the first time, this study has shone a spotlight on menstrual stigmas that are still upheld by society and science. Let’s unpack further what this study revealed as we delve deeper into this provocative question about a better way to determine heavy bleeding.


Unmasking the Inaccuracies of the PBAC Chart

The study conducted by the Department of Medicine at the Oregon Health & Science University (and published in the BMJ Sexual & Reproductive Health) was understandably triggering on social media as just one more example of how women’s health issues have been historically shortchanged. Especially when it just seems logical that testing should be conducted using the same substance for which it is used, i.e. blood. It was also the first to test the absorbency of reusable products, namely period cups, discs, and underwear.


While many social media commenters shared that they feel lied to by scientists and period care manufacturers, is testing products with saline a problem? Because discrepancies were revealed between reported and actual absorbencies, the study by proxy calls into question how doctors determine HMB.


Do you know how there’s a chili pepper spiciness rating? All around the world, there’s a recognized chart called the Scoville Scale used to standardize how we rank heat levels of particular foods.


In the period care industry, a similar chart exists to help professionals determine how much blood is lost during menstruation called the Pictorial Blood Loss Assessment Chart (PBAC), which relies on tampon and pad saturation as the gold standard.

The problem is that the PBAC chart is not that standard:

  1. Many versions exist.

  2. It presumes that all tampons and pads have standard and equal absorbencies and do not account for bamboo, for example, or other products, such as period underwear, cups, and discs.

And now, this latest study's findings cast further doubt on the chart's precision because pad absorbency has historically been based on saline solution absorbency. Yet the testing revealed that pads and tampons absorbed less blood than they did water. So when doctors reference how many pads or tampons a patient saturates to determine extreme blood loss, it’s inaccurate.

It should also be noted that we don’t know what brands they tested. There is no standard lab test on how companies share their absorbency.

The Challenge With Using Blood for Studying Period Product Absorbency


What’s the deal with period care commercials and using blue liquid? When we envision menstrual care absorbency lab tests using saline water in labs, this is what we imagine. So the excitement around a study using blood for their period product absorbency study drives excitement arising from its potential to disrupt long-standing stigmas and challenges existing paradigms in menstrual research. So what’s the problem?


Incomplete Representation: Using human blood in these tests does not offer a complete representation of menstrual fluid. Menstrual blood consists of more than just red blood cells; it contains uterine lining, blood clots, vaginal fluids, and other components that affect absorption differently. Therefore, blood cannot be considered a perfect substitute for menstrual fluid in testing.

  • Lack of Standardization: One of the primary issues with using human blood for scientific testing is the absence of standardization. In scientific experiments, consistency and reliability are paramount. Human blood varies significantly among individuals, considering factors such as blood type, health conditions, and hydration levels.

  • Ethical and Practical Concerns: Another critical issue is the ethical and practical aspect of working with human blood. Our society faces a shortage of blood for medical purposes, and using it unnecessarily for testing is an extravagance we cannot afford.

The researchers used expired packed blood cells, the bagged kind found in blood banks, which are just red blood cells separated from whole blood.


It may be argued that expired blood may be used in such tests since blood can’t be kept forever. Yet blood is a biohazard and experimenting with it can introduce pathogens, putting everyone in the lab unnecessarily at risk.


The Bloody Solution

A Synthetic Solution to Testing


When it comes to testing menstrual care products, using real blood is not essential since excellent synthetic liquids exist that can more effectively replicate menstrual blood than packed red blood cells (blood with plasma and platelets removed) that were used in this study. Ideally, scientists would design a synthetic menstrual blood that would be the smoothest, clot-free version of menstrual blood.


Conversely, they would design synthetic menstrual blood at the other end of the spectrum that is thick and full of clots, for example. In this way, you would test for two extreme versions of menstrual blood—which then covers every type of blood in between. Because there is no standard menstrual experience and no two periods are the same.

In the pharmaceutical and scientific industries, there is a growing shift towards using synthetic materials and 3D-printed tissues that mimic human or animal tissue. This approach aligns with a broader effort to make scientific research more humane, reducing our dependence on human and animal resources for testing. Companies like Voxcell and Axolotl Biosciences in Victoria, BC, are pioneering this approach with remarkable success.


PBAC Pushback


Additionally, it's crucial to acknowledge that no chart or test can fully account for the diverse range of menstrual experiences. The study's critical perspective challenges us to rethink our methods and strive for more accurate and compassionate menstrual health research. At the diagnostic level, doctors are called to do their due diligence when diagnosing heavy menstrual bleeding. Referring to product saturation and measuring the amount of blood loss is only one symptom of heavy menstrual bleeding because there are many variables, including:

  • Age

  • Medications

  • Hydration levels

  • Co-occurring conditions


What Should Menstruators Do?


Doctors must take into account all these factors when determining menstrual issues. What’s normal for one menstruator may not be normal for another.


So when should you be concerned about heavy menstrual bleeding?

  • Bleeding for more than seven days (called Menorrhagia)

  • Passing blood clots the size of a quarter or larger

  • Sudden gushes with large blood volume


Your healthcare professional may also ask you if you’re soaking through your pads and tampons, requiring you to change them due to being completely saturated every four hours or less over several hours.


But since the absorbency of different products varies vastly, a more accurate measurement is to use a period cup or disc that captures all your menstrual fluid. Those using pads, tampons, and period underwear could also weigh the product before use and again when changing it over four days; if the total weight exceeds 75-80 ml, it may indicate a concern worth discussing with a healthcare provider.


It also helps to track your period and record other qualities as well, including color, smell, cramps, and other observations. It's essential to remember that menstruation is highly individual, and any concerns should always be addressed by a medical professional.



While the recent study has drawn attention to the inaccuracies of the PBAC chart and the potential benefits of using menstrual blood in testing, it’s important to consider alternative approaches. Instead of using real blood, let's embrace synthetic materials that already exist, offering more variety of conditions for testing. No chart or test can fully account for the diverse range of menstrual experiences. Personal preferences will always play a significant role in choosing the right menstrual product. The study's critical perspective challenges us to rethink our methods and strive for more accurate and compassionate menstrual health research. In the meantime, let’s keep the conversation going and break down more menstrual stigmas!