Derived from the urine of pregnant mares, Premarin is peddled by a pharmaceutical multinational as a panacea for menopausal women. Illustrating a classic nexus of ecofeminist issues, this essay exposes the drug’s harmful impact on women, animals, and the environment, and suggests natural alternatives.

This article was originally published in 1994 in The FAR Newsletter.

By Cathleen McGuire

Did you know that synthetic estrogen is a known carcinogen? Did you know that this popular drug entails the slaughter of thousands of baby foals? Did you know that most estrogen prescribed for menopausal women comes from the urine of pregnant mares?

Increasingly, women approaching menopause are being pushed by the medical/pharmaceutical industry to consider hormone replacement therapy. Underneath this ostensible concern for women's health is an issue that poses enormous consequences for women, animals, and the environment.

Ayerst, a pharmaceutical company based in Montreal, is a division of American Home Products, a multinational corporation. Ayerst has a virtual monopoly on the pregnant mare's urine (PMU) industry. Their plant, Ayerst Organics, in Brandon, Manitoba, Canada—the only one in the world—acquires estrogen-rich urine from approximately 75,000 mares on 485 PMU "farms" in the Prairie provinces and North Dakota. (In 1992, Ayerst paid PMU producers $44 million for urine, or about $17 a gallon.) Ayerst then ships the extracted estrogen to its main plants in Montreal and New York where it is manufactured into Premarin, the world's leading hormone replacement drug.

Through artificial insemination the mares are all methodically impregnated to be on the same eleven-month gestation cycle. Percheron and Belgian draft horses are the breeds of choice since the larger the animal, the more plentiful the urine/estrogen yield. From approximately September to April, when their estrogen production is highest, the pregnant mares are catheterized and confined to narrow stalls. An Edmonton newspaper article explains:

"The horses are kept in stalls with a kind of rubber cup attached to their business end. The urine drains through a network of hoses to a stainless steel tank where it's kept chilled until pickup.

"Flexible rubber bands keep the cup in place but allow a horse to move about in the stall or lie down. Groups of five are exercised every two or three days."

Animal rights groups such as the Manitoba Animal Rights Coalition (MARC), however, claim that in reality the only exercise the animals get is from sitting down and standing up. The treatment of the horses is very similar to that of intensively raised dairy cattle. According to PMU farmer, Rocky Cartier, "It's paid the same, it's handled the same as dairies, everything is exactly the same. In fact, the bulk room where the tank is was altered to dairy specs two years ago."

Anxious to avoid any hint of a horse abuse scandal, the industry compiled a detailed Recommended Code of Practice that farmers must adhere to. Yet groups such as MARC continue to expose inhumane practices. For example, the average horse measures eight or nine feet, yet the guidelines allow for stalls as short as six feet in length. MARC has also been conferring with a former employee from one PMU farm who claims she can document the death of seven mares.

Death in fact is a given in the PMU industry. Although some foals end up as riding ponies in the hands of private owners, the vast majority of the 75,000 baby horses born each year are treated as mere by-products. They are separated from their mothers, and trucked long distances to feed lots where they are reared for eventual slaughter as horsemeat. Ayerst refuses to assume any accountability claiming the ". . . farmers—not Ayerst—are responsible for sending the foals to slaughter."

Tom Hughes of the Canadian Farm Animal Care Trust (CANFACT) states:

"Colts and cull fillies are typically sold by PMU farms at four to five months of age, just as their mothers are impregnated again. They may or may not be fattened by the purchasers before slaughter, depending on horse flesh prices. Fillies who show the temperament and conformation to become PMU producers are kept as replacements for worn out or infertile mares, or are used to expand production."

Hughes estimates that 300,000 to 400,000 horses a year (including surplus thoroughbreds, wild horses, and pleasure horses) are slaughtered for human consumption by the Canadian horsemeat industry. Since most of the horsemeat is exported to Europe and Japan (where it is considered a delicacy), domestic protest has been minimal. With its steady and plentiful supply of foals, the PMU business guarantees ever more profits for the expanding horsemeat industry.

With huge numbers of baby boomer women entering menopause, the equally lucrative hormone replacement business is positioning itself for a gold rush. Ayerst is pouring $100 million into its Brandon plant, augmented by a $20 million Western Economic Diversification Fund subsidy from Canada's federal and provincial governments.

Hailing the expansion as a "success story," politicians and Ayerst representatives—all men—are boasting of increased employment for the area. Many farmers are eager to be accepted by Ayerst as PMU suppliers with reportedly ten applicants for every opening. Les Burwash, a Calgary horse specialist, claims, "It's a good, sound agricultural enterprise . . . certainly one of the real bright lights in agriculture."

What no one is bragging about, though, are the acute environmental problems resulting from the manufacturing process. The stench from the by-products is notorious. Ayerst was allowed to expand operations on condition that they build a new dumping station to eliminate the noxious animal feces and ammonia wastes. The dumping station, however, threatens to overload the city of Brandon's sewage treatment plant. This would pose serious problems for the water quality of the Assiniboine River, a source of drinking water for thousands of Canadians.

The water-soluble ammonia is also lethal to fish and other aquatic life. According to Bill Paton, a member of Manitobans Against the Assiniboine Diversion, "Ayerst already has a history of non-compliance with the Clean Environment Commission and the smell from the plant is getting worse."

Marianne Cerilli, a Member of the Manitoba Legislative Assembly, is calling for an immediate basin-wide federal environmental assessment. Along with her outrage over the dangers to the environment, Cerilli is also alarmed about the potential health hazards facing women who take Premarin. "We should be asking just what the long-term effects of Ayerst's product will be on the environment of women's bodies."

In the 1960s, estrogen was extolled as a wonder drug. It is now known that there are links between synthetic estrogen and endometrial cancer, not to mention other "side effects." In the 1980s, another drug, progesterone, became routinely administered with estrogen to counteract cancerous effects. Proponents of Premarin cite its effectiveness for the prevention of osteoporosis and relief from vaginal dryness, hot flashes, and other menopausal concerns.

The U.S. Department of Health and Human Services, however, estimates that only fifteen percent of women find menopause "disruptive" enough to seek "treatment." For those fifteen percent who do feel they would like help, primary questions remain: Have the full effects of Premarin been thoroughly investigated? Can we trust Ayerst's test data? Does Ayerst use lab animals as research subjects?

In response to the ethics of using Premarin, some doctors have indicated they would be willing to prescribe cruelty-free alternatives. Laboratory-made substitutes such as Estraderm (Ciba Pharmaceuticals), Estrace (Mead Johnson), and Ogen (Abbott Labs) have been recently approved by the Food and Drug Administration. The downside is that these lab-made synthetics are about twice as expensive, and once again, we do not know the full extent of their dangers or the degree of animal experimentation involved.

Ultimately, I regard all synthetic hormone replacements as one big toxic experiment on women. There are natural estrogen alternatives that mainstream sources rarely mention. I would like to share my own experience.

When I was twenty-five, I underwent a hysterectomy, trusting my doctor knew what was best for me. Although my uterus, Fallopian tubes, and ovaries were severely afflicted, there were no signs of malignancy. Nonetheless, my gynecologist adhered to an AMA tradition: When in doubt, cut them out. (Funny, if one gets a fat lip, cutting it off is not usually advised.) He then warned me about the dangers of osteoporosis, a lowered voice, and the possibility of growing facial hair. Faced with either risking these disturbing consequences or taking synthetic estrogens, I barely gave it a second thought. I took Premarin without fail for over fourteen years, eventually adding synthetic progesterone.

A few years ago, however, I became involved in a monthly menstrual circle. We celebrated women's ability to cycle in rhythm with the moon and the primordial healing power of women's menstrual wisdom. I began to explore the politics of surgical menopause and the pharmaceutical-industrial complex's encouragement of synthetic hormone replacement therapy.

I asked my gynecologist (now female and feminist) about holistic alternatives to synthetic hormones. She had no clue. Schooled on medical journals that are tethered to pharmaceutical advertising revenues, she consistently rejected non-synthetic estrogen possibilities.

I finally found a chiropractor/clinical nutritionist who helped me traverse new terrain. I no longer take synthetic hormones. I now get my estrogen and progesterone naturally from supplements derived from soybeans and wild Mexican yams respectively. Because natural estrogens present none of the dangerous side effects frequently associated with synthetic estrogens, I am convinced they are a much safer hormonal substitute.

To maximize the potential for success, I am also on a sugar-free, organic vegan diet, and a daily regimen of vegetable juice, vitamin supplements, and exercise. Vegetarians generally have lower estrogen levels, which contributes to an overall decrease in risks.

In the controversial world of hormone replacement therapy, it is anyone's guess which protocol will prove lastingly effective for menopausal women. I for one decided I would rather pursue a more holistic path centered around natural plant derivatives than subject myself to environmentally harmful, potentially carcinogenic drugs extracted from the urine of pregnant, oppressed mares.

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