Menstrual Cups

Animal testing

The topic of animal testing has been brought up on a couple of the communities I am on over the last couple of days, so I thought I would address this here, so that people can get the information I currently have on this.


In short, it would appear that yes, Medical Grade Silicone and TPE materials are tested on animals, depending on the class level is is being certified to.  So it may not be possible to find a cup (or any other medical grade silicone/TPE product) that is not linked to animal testing at all.

Now, to clarify – this testing is done by the manufacturer of the silicone/TPE material.  The cup companies themselves would not be involved.  So if the cup company says their cup is not tested on animals, that would be correct.  Their cup itself would not have been.  If they say their silicone is not tested on animals – that is also correct.  The batches of silicone/TPE they use likewise probably wouldn’t have been tested on animals either. But the company supplying the silicone/TPE has probably done animal testing on initial batches of the product to check that material is safe for prolonged use in human bodies before they could sell it for medical use. But subsequent batches made should not need testing. And it seems they will also do testing on specific batches on request.

So whether or not this animal testing issue makes a difference to you, depends on if you’re happy so long as the material that is in your actual cup was not tested on animals. Or if you are against any form of connection to animal testing, including any testing done by the manufacturer on previous/different batches of material. (In which case, you may find all brands of cup are “tainted”)

To know for sure, we would need to know where the cup companies buy their silicone, and see if those manufacturers have done animal testing on any of their products… I have a feeling though that all manufacturers will have done animal testing.

There are a couple of brands we do have details for, and those will be added here for easy reference.  The manufacturers also have a section with more info further down the page.

Gaia – Uses “Wacker” brand “Elastosil” silicone. Has certification documentation on their site showing animal testing was done on that form of silicone.

LadyCup – Doesn’t say which brand they use, but they do say: “The material used is Liquid Silicone Rubber from the German company. LadyCup® has been awarded the “Certificate of Compliance with USB Biological Tests, Classification VI” (Bioservice – Scientific Laboratories).” – Class VI indicates animal testing.

MeLuna  – Uses “Kraiburg” brand “Thermolast M” TPE.  Has certification documenation on their site showing animal testing was done on that form of TPE.

Mooncup UK – Has said in an e-mail to a member of the community: Legally, chemical formulas and many raw ingredients (such as medical grade silicone) will have to have undergone animal testing at some point historically in order to prove to approval authorities that they are safe for consumption/use. In the case of the Mooncup, any historical testing of medical grade silicone will have been undertaken well before the creation of the Mooncup in 2002.  The medical grade silicone used to make the Mooncup has therefore not been tested on animals by Mooncup Ltd, or on behalf of Mooncup Ltd by any third party over whom Mooncup Ltd has effective control.

Yuuki – Uses “Momentive” brand “Silopren LSR 4050” silicone.  Has certification documentation on their site showing animal testing was done on that form of silicone.


If you want the longer version – keep reading 😀

I’m actually really busy with stuff at the moment, and don’t have time to research this further, but the details I have are here, if anyone would like to research this more, please let me know what you find out!


What I’ve been able to find out….

It would seem that there are different biocompatibility ISO standards, and USP classes for medical use.  Some testing for these is done on cells, not living creatures, but some are done by injecting and/or implanting the material into mice and/or rabbits.

I am unsure at this point if those standards are a voluntary thing, or if they are required by the FDA or similar bodies to have the products made from that type of material approved for sale.

Toxikon has a pdf guide to what the tests include and what tests are needed for which USP class.  It would seem that all classes (1-6) require injecting the compound into animals.  Classes IV and VI require implanting the compound into the muscle of a rabbit.

I don’t (yet) know if the the silicone/TPE that menstrual cups are made from needs to be to be classified under those classes to be FDA approved.  So it may be that menstrual cup silicone only needs the lower level testing that is not done on animals.  But it is likely that animal testing would be needed, and even if it’s not the same manufacturer would likely be testing to the higher class for silicone sold for other medical uses.


I have looked up the details for a couple of large silicone and TPE suppliers.  Info on them is below.


Dow Corning
Dow Corning, who claims to be one of the leading suppliers of silicone – has a FAQ on their website, and in that it lists the animal testing done for the different classes.  Not only do Dow Corning participate in animal testing, they test for 7-30 days, rather than the 5 day minimum required.  I e-mailed Dow Corning to ask if they have any medical grade silicone that is not tested to class VI (eg not tested on animals) – they do not.

“Class VI requires the most stringent testing of the six classes. Extracts of the test material are prepared in saline, alcohol in saline, polyethylene glycol (PEG 400), and vegetable oil. The extracts (diluted in the case of the PEG extract) and blanks are injected into mice and rabbits, which are observed several times over a 72-hour period. The animals’ response to the sample extracts and the blank are compared to determine test passage. These tests of extracts are called the Systemic Injection Test and the Intracutaneous Test. Materials that pass these two tests are compliant with USP Class V.

USP Class VI includes the tests of USP Class V plus an implantation test wherein strips of the test material and a negative control are implanted in rabbits for a period of not less than 120 hours. Hemorrhage, necrosis, discolorations, and infections are macroscopically observed and degree of encapsulation is scored and compared with the negative control to determine test passage. Note that the 7- and 30-day implantation test protocols utilized by Dow Corning exceed the 5-day (120-hour) USP Class VI implantation minimum requirement.”


Kraiburg (Meluna supplier)
Kraiburg has a “Thermolast M” variety of TPE.

“All medical compounds are tested according to ISO 10993-5 (Cytotoxicity) and listed as Drug Master File. Selected medical compounds are tested according to described medical basic approvals: USP Class VI (chapter 88), USP 661 (in vitro), ISO 10993-4 (Haemolysis, indirect in human blood), ISO 10993-10 (Intracutaneous Irritation) and ISO 10993-11 (Acute Systemic Toxicity).”

So it says “Selected medical compounds are tested” for the ones on animals.  Which may mean that some of their Thermolast M range of TPE is not tested on animals?

However, there is a certificate issued by “Toxikon” to Kraiburg, which can be downloaded here, that includes this section specifically relating to the animal testing that the Thermolast M TPE was subject to:

“The test article extracts and corresponding blanks were injected systemically and intracutaneously in mice and rabbits respectively.”


“In addition, the test article was implanted into the paravertebral muscles of rabbits for 7 days and observed macroscopically for signs of hemorrhage, necrosis, discoloration, encapsulation and infection.”

There is also the “ISO-certificate, verifying the biological safety of TPE” document on the MeLuna website, that is seems to be basically a coverletter for the above certificate, that says:

“This is to certify that the biological safety performed under ISO 17025 accreditation status, as indicated in the above referenced USP class VI report, can be used as compliant results with the ISO 10993-10, tests for intracutaneous irritation and 10993-11, tests for systemic toxicity.”


Momentive (Yuuki supplier)
Momentive’s  “Silopren LSR 4050” silicone is tested on animals, as it states it meets the USP Class VI:

“Regulatory Compilance
A representative sample of an analogous product to Silopren LSR 450 met the requirements of USP Class VI (maximum contact
time with human tissue 28 days) and ISO 10993 under Good Laboratory Practices (GLP).”

Wacker (Gaia Cup supplier)
Wacker’s “Silpuran” brand of silicone is also tested on animals:

“Medically Relevant Properties
The SILPURAN® product line offers a compelling property profile to meet medical-technology needs:
•Available in a wide range of hard-nesses (Shore A)
•Excellent heat resistance as well as chemical and physical resistance without additional stabilizers
•High level of transparency and colorability
•Good resistance to UV radiation and X-rays
•Certified biocompatibility (ISO 10993: cytotoxicity, sensitization, pyrogenicity; USP Class VI: systemic toxicity, intra-cutaneous toxicity, and implantation for 5 days; further tests on request)”



Further info on MeLuna
I’m only mentioning this, because I feel that a cup company should be honest and not misleading.  MeLuna claim not to know anything about animal testing and said to contact the supplier for details. 

However, MeLuna has a section of downloadable files on their site, to prove their product safety – that specifically mentions the animal testing for the “TM 4 Med” version of the TPE.

At the date of writing this article, MeLuna appear to have removed the certificate document from their site, although the text for the link remains (“TPE Test Result Certificate“).  A member of the menstrual cup community contacted MeLuna asking about animal testing, and that member claims that the above certificate was on the site when they contacted MeLuna, but was removed from the site the next day.

Luckily, back in 2011 when I asked them to comment on the safety of the coloured cups – they provided me with these same documents, so I still have a copy of that file that is no longer on their site. It can be downloaded here if it is still unavailable on their site.

The fact that they have (or had) documents on their website explicitly mentioning animal testing on the material they are using, yet claim not to know anything about it,  means that either they didn’t read those documents themselves (which isn’t a good sign), or they actually were aware of it and don’t want to admit that.

Now it is possible that the “TM 4 Med” version of the TPE (which was tested on animals) may not be what MeLuna uses – They say they use “Thermolast M” – but the number 4 in the product that was tested, may indicate that it was tested to class 4 (IV), which does require implantation testing.  So there may be a different version of “Thermolast M” that wasn’t tested on animals?  I don’t know.  So that may be why they removed that certificate, it may not have been applicable to the particular TPE batch they are using.  Or they may have wanted to hide that document.

Though removing the document but leaving the link to it still on the site, and not explaining anything to the person who contacted them, is not being terribly open about the matter.


My thoughts

Much as I don’t like the idea of animal testing – I can see why it is important to make sure the materials are safe.  Especially since some medical items made from silicone and TPE are used in the body for extended periods of time (eg heart valves and the like).  While I don’t like the idea of animals suffering, I also don’t think it’s right to just implant something into a human and hope they don’t die from it.  So they do need to make sure it’s not likely to cause problems, and while some tests can be done on cells not living creatures (obviously the preferred way to do it!), some may need to be done on living tissue still connected to the creature, to allow for a proper reading of how reactive it is.  Which, sadly, is just how things sometimes are 😦


Link to an article on how testing is trying to be more humane and using cells rather than live animals where possible:

Links explaining the Class VI and ISO certification process


February 2, 2015 - Posted by | news


  1. Also the Elastosil type of silicone, that the Gaia cup apparently is made of.

    And from the Yuuki site : “The YUUKI menstrual cup is made from liquid silicone rubber Silopren LSR 4050 . Elastosil produced in Germany by company Momentive.”
    In the search results, I also see LR 3003 for Yuuki, this one being made by Wacker.
    Are the Elastosil suppliers used to do animal testing (?)

    By mere chance, do you know which cups would be made with the “Silpuran” type of silicone?

    Comment by Quitterie | February 3, 2015

  2. Interesting….Thanks!

    Yuuki has testing certificates – though they only show photos of them and they are difficult to read, but it also confirms animal testing via implantation

    The Silopren LSR 4050 from Momentive data sheet:
    (also confirming they are “met the requirements of USP Class VI (maximum contact
    time with human tissue 28 days) ” – which indicates implantation testing.

    Gaia has the testing certification on their site – which says it was tested with implantation for 90 days

    Click to access scheda_sicurezza_silicone_wacker_gaiacup.pdf
    “ELASTOSIL®silicone products, with their universal range of properties, are used in the most varied industrial applications. Their near-to unlimited potential makes them ideal for applications in almost all industries – such as automotive and mechanical engineering, electronics and electrics, textiles, baby articles, toys, domestic appliances and sports articles, as well as the construction industry.”

    Strange that since Gaia is sourcing from the same company that does the version that specifically talks about high standards in medical applications, and Gaia would go with the more generic version.
    “SILPURAN® products are high-quality silicone rubber compounds that comply with the strict requirements of the health care sector. All products are tested according to selected ISO 10993 tests and USP class VI, and thus also fulfill the health care sector’s high safety standards. ”

    So I will update the post with these

    Comment by obsidian | February 4, 2015

  3. Thank you for all the information! I have a small correction: In Silico studies are performed on computer or via computer simulation.

    Comment by S | August 26, 2016

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