Is Your HRT made from Pregnant Mare’s Urine?

Screenshot from the Premarin website

If you’re pre or post-menopausal you may have been prescribed or even begged your GP for Hormone Replacement Therapy (HRT) to try and relieve some of the awful symptoms. Perhaps you’ve read up on the wonders of bioidentical hormones and decided you’d like to try them. But, if your experience is anything like mine, you would have been fobbed off by your doctor and told that bioidentical HRT is too difficult to take, or there’s not enough known about it, and been handed a prescription for Prempak-C or Premarin.

What is Premarin?

If you’ve been prescribed Prempak-C, Prempro, Premique, Premarin or the combined menopausal-osteoporosis drug Duavee (formerly known as Aprela), you have been prescribed a synthetic form of HRT that contains conjugated horse oestrogens.

The Premarin family of drugs contains estrogenic compounds that are made from the urine of pregnant mares. That’s where the name is derived from: PREgnant MAres’ urINe = Premarin. Any HRT with Prem in the brand name is likely to contain conjugated equine (o)estrogen (CEE).

Although it sounds disgusting, you may still be wondering what the fuss is all about. After all, we may eat gelatin or inject Botox, and most of the time we have no idea what ingredients are in our medicines or beauty products. So what’s wrong with a little pregnant mare’s urine if it’s going to get rid of your hot flushes and make you feel better?

The problem is two-fold. Firstly, drugs containing CEEs are not well tolerated by the human body and the Premarin family of HRT increases the risk of suffering from thrombosis or a heart attack or breast cancer. And secondly, treatment of the pregnant mares is very cruel.

The Women’s Health Initiative Study and Risks of Prempro Use

Back in July 2002 the Women’s Health Initiative (WHI) study into hormone therapy was stopped abruptly because it was clear that long-term risks of Prempro use clearly outweighed the benefits. Prempro was a combination pill made up of Premarin and Provera, a synthetic form of progesterone. Women in the study on Prempro were found to suffer more breast cancers, heart attacks, strokes and blood clots than the women taking the placebo.

The results of the WHI study sent shockwaves around the world and women stopped taking HRT in droves. Doctors stopped prescribing it and for over a decade there was a lot of confusion around the safety of HRT.

Unfortunately, when the results of the study were publicised, no distinction was made between synthetic conjugated horse oestrogens like Premarin and bioidentical oestrogen and progesterone.

Bioidentical Hormones

Bioidentical hormones are synthesised in laboratories from hormone precursors found in soybeans or yams and their molecular structure is designed to be an exact replica of the hormones produced by your body. This means that they are easily recognised and produce few of the side effects and diseases associated with synthetic hormones.

The Risks Associated with Premarin

Premarin tabletsAccording to Dr Uzzi Reiss in his book The Natural SUPERWOMAN, some of the risks and side-effects associated specifically with Premarin include:

  • Inflammation
  • Increased body fat
  • Cardiovascular events
  • Arterial sclerotic disease
  • Venous thrombosis (blood clots in veins) and
  • Migraine headaches.

And recent research published in JAMA Internal Medicine Journal in January 2014 found that “CEEs use was associated with a higher risk of incident venous thrombosis and possibly myocardial infarction than estradiol use.”

Premarin is the Most Commonly Prescribed HRT in the USA

Premarin is manufactured by global pharmaceutical giant Pfizer. On their website they say “PREMARIN is the #1 prescribed branded estrogen therapy for the relief of moderate to severe menopausal symptoms.

It begs the question, if so much is known about the risks of Premarin, why are so many doctors continuing to prescribe it for their menopausal patients?

PMU Farming and Cruelty to Horses

Apart from the obvious health risks to women, there is also the issue of cruelty to horses. People for the Ethical Treatment of Animals (PETA) describe how the pregnant mares are:

“Tied in small stalls, unable to move either backwards, forwards, or sideways or lie down comfortably, they stand with sacks strapped to their groins for months on end. In order to make the urine more concentrated, their water intake is restricted, so the horses are constantly thirsty. The foals are considered “byproducts,” and most are fattened up, slaughtered, and sold for horsemeat or turned into dog food.”

Premarin horses in stallUp until 2002 Pregnant Mares Urine (PMU) farming was big business in North America and Canada. Hundreds of PMU farms churned out gallons of oestrogen-rich pregnant mares’ urine on a daily basis and were handsomely rewarded by large pharmaceutical companies like Wyeth and Pfizer.

But the WHI scare saw a drop in Premarin and Prempro sales and after 2002 many PMU farms were scaled down. Now, according to equine advocacy organization The Horse Fund, most PMU farming has been relocated to countries with less regulation, like Kazakhstan and China, which has a reputation for animal rights abuses.

Just Say ‘No’

With so many safer alternatives on the market it seems unnecessary to still be manufacturing synthetic oestrogen from pregnant mare’s urine. Not only is it a cruel practice, but it is harmful to the health of the women who are prescribed it.

So, if your doctor prescribes you Prempak-C or Premarin, refuse to accept the prescription. You are under no obligation to accept it. Object on the grounds of animal cruelty and the fact that it is associated with higher risks.

Ask for bioidentical hormones (usually in the form of oestrogen patches or gel and Utrogestan progesterone capsules). If your doctor is reluctant to prescribe them, ask for a referral to a Menopause Clinic or a Gynae-Endocrine Consultant at a hospital.

If more and more women refuse to take this product, there will no longer be a commercial reason to manufacture it. And that will not only benefit the health menopausal women around the globe, but those poor suffering pregnant mares as well.

“We are not spiritually unconnected from the drugs we take, or the pain and suffering that goes into their making.” — ALICE WALKER


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23 Responses to Is Your HRT made from Pregnant Mare’s Urine?

  1. jessie October 26, 2017 at 9:46 pm #

    Hi Angie,
    I have been on prempak c for 23years! Been great . Now discontinued so have been given everel conti patches . I have not started them yet, could have, last week,but thought i’d maybe not bother as I feel ok so far! thats’s till I really got surprise after scrutinising my face in mirror and to my horror the skin I was so proud of has finally changed so drastically, in 2 weeks. Can this be right? I am going to start patches tomorrow needless to say . Will my skin recover do you think? I am 72 and our family skin genes are all good. My Dear late mother had no wrinkles at 91! Please help. Thank You.

    • Angie Macdonald October 27, 2017 at 12:22 pm #

      Hi Jessie. Thanks for getting in touch as I was unaware that Prempak-C had been discontinued. Personally, I feel that Evorel Conti patches are a much better bet as the oestrogen in the patch is bioidentical and has not been manufactured from pregnant mare’s urine, a very cruel process. With these patches you won’t have a monthly bleed, which I would see as a major advantage. If you do have any problems it may be because the synthetic progestin in them is different to the progestin in Prempak-C. It’s always a good idea to give a new HRT regimen 3 – 4 months to allow your body to adjust to it. But if you feel unusually depressed, irritable, suicidal, bloated and put on weight or have very tender breasts, you may have to experiment with other forms of HRT that contain different types of progestins.
      As you have been on HRT for so long I think it would be a much safer bet if you were to have natural progesterone in the form of Utrogestan tablets as natural progesterone does not increase the risk of breast cancer, but synthetic progestins do. If you were to go down this route your doctor would have to prescribe you oestradiol patches separately. I hope this helps.

  2. Alice Walkers October 9, 2017 at 7:17 pm #

    Hello Angie,

    I currently take HRT in the form of Evorel transdermal patches (Estradiol) for transgender MtF transition.

    Do you know if Evorel patches are produced using pregnant mare urine?

    If not, could you advise whether they contain any other animal ingredients? I am looking to follow a vegan lifestyle, and want to ensure that my medication contains as few animal ingredients as possible.

    Many thanks.

    • Angie Macdonald October 9, 2017 at 7:22 pm #

      Hi Alice. You’re in luck as Evorel patches are a bioidentical form of oestradiol and definitely NOT made from pregnant mare’s urine.

      • Alice Walkers October 10, 2017 at 11:19 pm #

        Many thanks Angie.

        Do you know where I could find any further details regarding whether or not Evorel patches are created with or contain any other animal ingredients?

        Or alternatively, if you have that information to hand, I would be very greatful to hear it 🙂

        Many thanks.

        • Angie Macdonald October 11, 2017 at 9:43 am #

          Hi Alice. As far as I’m aware Evorel patches are free of animal products. Apart from the oestradiol the other ingredients are Adhesive acrylic polymer (Duro-Tak 387-2287)
          Guar gum (meyprogat 90) and Hostaphan MN19 (polyester film – removed before application). Information about Evorel patches is available on this site:
          Hope that helps.

  3. Keeley August 28, 2017 at 11:00 pm #

    So I’ve just had a total hysterectomy been put on femsevern conti patches, does this contain horse urine? I am due to go back to my doctors this week and I want bio identical hrt but don’t know the name of any, can you advise me on a good natural hrt to ask for?

    • Angie Macdonald August 29, 2017 at 10:09 am #

      Hi Keeley. FemSeven Conti is meant to be prescribed for postmenopausal women with a uterus. They contain a combination of oestradiol and a progestin (synthetic progesterone). Why a doctor would prescribe that for a patient who has just had a total hysterectomy I have no idea as you would only need the progestin to make sure you don’t get endometrial cancer of the uterus and have a period each month to shed the lining. The mind boggles! Most women who have had a total hysterectomy only need to take oestrogen. A good bioidentical oestrogen patch is Evorel. Or there is the bioidentical gel called EstroGel. All available on the NHS if you are in the UK. Some women find that their libido and sexual response is badly affected by the hysterectomy in which case you should ask to be prescribed some testosterone gel like Testim gel. Your doctor will have to prescribe it off-label as it is not licensed for women, but this is quite a common thing to do. Good luck and please let me know how you get on.

      • Keeley August 30, 2017 at 1:48 pm #

        Hi Angie
        Thank you for your advice, I’ve been back to the doctors today she said she thought i was on fem seven not fem seven conti so she’s changed it to Evorel but as for the testosterone she can’t proscribe me that she will have to refer me to a specialist…….. let’s just hope I don’t need it!
        Thank you so much again!!

        • Angie Macdonald August 30, 2017 at 4:47 pm #

          Hi Keeley. Great that your doctor prescribed Evorel! Hopefully you’ll feel good on it and won’t need anything else. Thanks for letting me know.

    • Angie Macdonald August 29, 2017 at 10:20 am #

      Hi Keeley. FemSeven Conti patches don’t contain horse urine, the oestradiol is bioidentical but they do contain a synthetic form of progesterone – a progestin – which you do NOT need having had a full hysterectomy. It is progestins interacting with oestrogen which can cause breast cancer. For women who have had a hysterectomy you only need oestrogen and this is quite safe when maintained at a low dose. Please ask your doctor for either Evorel patches or EstroGel – both are bioidentical and contain oestradiol.

  4. Lisa November 3, 2016 at 5:16 pm #

    I’m so disgusted that I’ve been taking this for 3 months and only just found out what it contains, I’ve got such strong beliefs in relation to cruelty to animals, I’m vegetarian bordering on vegan, eat nothing where an animal suffered or died, no fish, no meat, not even eggs! Why has my doctor not spoken to me about this before prescribing 🙁

    • Angie Macdonald November 10, 2016 at 6:33 pm #

      Hi Lisa. Good question. Either your doctor doesn’t know or doesn’t think it’s an issue. Or it may be that it’s the cheapest form of HRT and so usually prescribed first for economic reasons. But your moral objections are a good reason not to take it and to ask for something bioidentical that has been derived from plant sources.

  5. Kathy S September 25, 2016 at 1:01 pm #

    Maybe I’m lucky that I live in the Uk and all the contraindications, warnings and risks are written clearly on the information leaflet ? This is the information that everyone should read before they take any medication. You can also look at further detail on the manufacturers website. I am looking into how Premarin is produced as… who wants horses to suffer to relieve their symptoms ? Not me. So I’m looking for current information on production. Thanks for the article. Off to continue my research.

  6. Joanne Ahrendt July 22, 2016 at 9:39 pm #

    I’m so glad I read this post, I was just prescribed these today and actually took one before I read this, so they are now going in the bin. I can’t believe they would do this to Women, I thought your Dr was supposed to help you not give you something that is bad for you – and those poor Horses – I am vegetarian as I don’t want to be responsible for any animals death and then I’m given a Pill that is made from the suffering of Horses – what is going on in medicine these days! I’m just so thankful I found this site before I took any more of them!
    Thank you!

    • Angie Macdonald August 1, 2016 at 7:05 pm #

      Hi Joanne. I’m glad this post helped you make an informed decision. My impression is that Prempak-C and other Premarin forms of HRT are prescribed because they are the cheapest form of HRT. And in today’s world, profits often come first, unfortunately.

  7. Lynne May 29, 2016 at 9:55 pm #

    Thanks very much indeed for this article. I think I might soon need HRT – I’m so glad I read this – I would have been horrifiedto discover later on that I might be prescribed a drug produced in this inhumane and disgusting way. many thanks indeed – from a horse lover

    • Angie Macdonald May 31, 2016 at 6:10 pm #

      Hi Lynne. Glad that the article helped. I hope you are prescribed bioidentical HRT if and when you need it.

      • Keeley H August 28, 2017 at 11:13 pm #

        Can you suggest a good make of bio identical hrt to ask my doctor for? I am on femsevern conti patches after a total hysterectomy which I had 3weeks ago. Thankyou

    • Kathleen Moore July 26, 2016 at 10:52 am #

      Those poor horses should be treated like the queens that they are .. not treated like they are being treated Jesus Christ!! That’s the cruellest thing iv ever seen and the poor foals .. why????? Fucking hell why??? I’m sickened .. and soo bloody angry that all this cruelty is exceptable ?? I’m at a loss for words ……

  8. animal respect October 17, 2015 at 12:41 am #

    if horses urine improves things for women great, but make sure the horses life is a decent one,this is as disgusting as battery chickens, and as for the foals, disgusting, but this is just what man does, makes a quick buck, and couldnt give a damm how he does it

  9. charles March 29, 2014 at 4:34 pm #

    The problem and what is not explained is that in our zeal to protect the horses, we are not at the same time explaining that these horse estrogens are the only estrogens proven to actually reduce the risk of breast cancer!!!!!

    There were two arms in the now infamous WHI study. In the one arm, women who did not have their uteri (hysterectomized women) took premarin estrogens with no progestins as they did not need them. Non-hysterectomized women (those with their uteri intact) took premarin plus a synthetic progestin known as “MPA”. The women who took the horse estrogens only not only had reduced breast cancer rates compared to women who took no hormones, the earlier the women started on the estrogen, the better their heart health looked. Premarin raises the good colesterol “HDL” and lowers the bad “LDL”. So called bioidentical estrogens due this much more poorly. In addition, “bioidentical” estrogens are much more potent inducers of breast cell stimulation and therefore breast cancer. People who tell you that “bioidentical” estrogens do not cause breast cancer are either ignorant or lying or a combination. The association between women’s natural estrogen levels and their risk of breast cancer is quite clear. Premarin estrogens are different, they do not stimulate breast cancer cells in the same way and there are several theories on this but more research is needed. We do not need to kill women to protect horses, do we?

    The argument that there are “safer” alternatives is absolute and total bullshit with no double blind placebo controlled studies to back them up. I love horses like crazy but I love women like crazy too and it absolutely crushes me to see so much propaganda and BS get passed on in order to advance a different agenda. Sign me pro horse and pro women!

    • Angie Macdonald March 29, 2014 at 5:51 pm #

      Hi Charles. You’re absolutely right in pointing out that in the infamous WHI study it was the hysterectomized women on Premarin only who had lower breast cancer rates (151 cases compared with placebo 199 cases). Unfortunately, when Premarin was combined with synthetic progesterone the women in the study didn’t fare as well. But a recent study in The Lancet came to the conclusion that “our data do not support use of oestrogen for breast cancer risk reduction because any noted benefit probably does not apply to populations at increased risk of such cancer.” In other words, if you’re at risk of breast cancer, taking Premarin is probably not going to help reduce that risk.
      While I agree that the jury is still out on whether or not bioidentical estrogens are better than CEEs or other synthetic forms, I think there is a lot of anecdotal evidence amongst women that they feel better on bioidentical HRT and suffer fewer side-effects. Many synthetic oestrogens are in pill form which result in high concentrations of estrogen passing through the liver causing the liver to make increased amounts of certain molecules that may promote atherosclerosis. Bioidentical oestrogens come in transdermal patches or gels thereby avoiding the first pass effect through the liver and are not associated with an increased risk of venous thrombosis. So in that respect they are safer. Taking natural progesterone in the form of oral capsules, transvaginal pessaries or gels may also reduce progestogenic side effects.
      So, I don’t think it’s propaganda and bullshit to make women aware of a) what is involved in the production of their HRT and b) the possible risks they may be exposed to. But as you say, more research is needed and the jury will probably still be out for years to come.

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