What is PMU?
What is PMU?
PMU is urine that is produced by a pregnant mare (female horse). The acronym comes from Pregnanat Mares' Urine, and is sold in various forms, such as pills, creams, injections, patches and rings. You have probably heard of Premarin® (PREgnant MARes’ urINe/urINE) or Premarine (the older, less popular, Canadian name). Premarin is an estrogen replacement product composed of conjucgated estrogens from PMU. Other drugs you may recognize are Prempro, Premphase, Prempac and Premelle. This is the most widely studied form of estrogen replacement therapy in the world—more than 3,000 scientific studies of estrogen have used Premarin.
The composition of Premarin is:
- estrone, equilin, 17 alpha-dihydroequilin; and
- smaller amounts of: 17 alpha-estradiol, equilenin, 17 alpha-dihydroequilenin as salts of their sulfate esters; and
- inactive ingredients: calcium phosphate tribasic, calcium sulfate anhydrous (white tablet only), calcium sulfate, carnauba wax, cellulose, glyceryl monooleate, lactose, magnesium stearate, methylcellulose, pharmaceutical glaze, polyethylene glycol, stearic acid, sucrose, talc, titanium dioxide.
Why is PMU Used?
PMU is the only human estrogen replacement therapy (ERT) or hormone replacement therapy (HRT) drug derived from an animal uses. It is used to reduce symptoms of menopause in women, used by women who have had hysterectomies, and can be used to treat osteoporosis. Some lesser known uses are:
- treatment of symptoms associated w/metastatic breast cancer in men/women
- prostate cancer in men
- by those who don’t produce enough estrogen—hypogonadism, castration, ovarian failure, intersex conditions
There are downsides to using PMU, such as an increased risk of endometrial cancer, stroke, blood clots and dementia. Since 1976 there has been a warning label about the risk of endometrial cancer from using PMU.
How is PMU Made into Premarin?
In 1930 Emmenin, a placental extract, was made by extracting the conjugated estrogens obtained from the late pregnancy urine of Canadian women. There was a need for a cheaper and more potent option, which led to research in Germany at the Berlin Zoo on pregnant equines (horses and zebras). This yielded potent, water-soluble, conjugated estrogens. Then in 1939 Ayerst, a pharmaceutical company, had a breakthrough in the extraction process, leading to PMU potency of 2.5% higher than in humans. This form of PMU was approved for use in Canada in 1941, and approved for use in the US in 1942. In 1943 American Home, which later became Wyeth, purchased Ayerst. Much later, in 2003-5 Wyeth resized and shifted to lower doses, leading to a reduction in its collection network. Now ranches are concentrated in Manitoba and Saskatchewan, with a few in North Dakota.
The PMU industry tells us that most farms are family-owned ranches. The mares’ urine is collected in loose-fitting, flexible, light-weight pouches, which allows for lying down and freedom to move about.
What are PMU Farms?
As of November 2003 there were only 308 PMU producing farms. The PMU industry tells us that a typical equine rancher has worked in the industry for more than 10 years, works the ranch with his or her spouse, child and one hired hand, cares for approximately 95 mares in production, and produces cereal grains and forages in addition to raising other livestock.
Conversely, from the animal welfare community, we hear that PMU farms, or “pee barns” have horrible conditions where pregnant mares live for about six months out of each year. They stand in small stalls with urine collection devices strapped to them and can’t turn or detach from the collection cups. Mares become pregnant by a stallion (there is no artificial insemination). 90% of mares carry to term and then stand in a small stall for about six months wearing a urine collection device. Next they are turned to pasture for final gestational month until they give birth. The foal is weaned and the mare is placed back in the herd with a stallion. This repeats.
The North American Equine Ranching Information Council (NAERIC) tells us that the mares' urine is collected using a loose-fitting, flexible, light-weight pouch that allows for a full range of movement, including lying down. It is held in place by a system of pulleys and is not directly attached to a mare. They state that horses are watered utilizing automatic water systems. Ranchers provide all of the waters their horses will drink, at least five times per day. Most ranchers water more often. The automatic watering systems ensure horses receive fresh water multiple times each day.
From the animal welfare community we learn that most of the foals bred in Canada are sold directly to meat processing plants. Colts (young male horses) have less than 1/50 of a chance to live. We are told that coals are taken from mothers in September whether or not they are fully weaned. Mares work their whole lives and are sold only after they are unable to become pregnant.
What Are the Laws?
Allegations of catheterized mares living in terrible conditions and foals being mistreated lead to the Ontario government issued regulations regarding licensing, citing and revoking permits (PMU Farm Act 1968-9, Reg # 217/70).
More than 13,000 people sued Wyeth between 2002-2009. For the most part, big pharmaceutical companies won these cases. Wyeth did suffer one big loss in 2006: $1.5 million in compensatory damages, with undisclosed punitive damages.
Some problems with the lack of laws and regulations are that PMU Ranchers follow a self imposed, self regulated Code of Practice for guidelines on ranch management, barn design, and care. The Animal Welfare Act (AWA) does not cover the production of PMU.
There are other issues involved with PMU farms:
- Foal adoption
PMU farms exist mostly in Canada, so US legislation and regulations are not applicable to farms not in North Dakota. See also: AEEP and AVMA.
Are There Synthetic Options?
On May 5,1997 the Center for Drug Evaluation and Research (CDER) at the Federal Drug Administration (FDA) said it will not approve synthetic generic forms of the estrogen therapy drug Premarin®. This is because these generic products have not been shown to contain the same active ingredients and, therefore, to work the same, as the original drug in treating women with menopausal symptoms.
Synthetic and plant-based estrogen drugs are available and many physicians prefer them to Premarin. One option is Amberen. It is likely that many synthetic options could be produced and marketed, but may not be cost-effective yet. One option is Bacteria. The FDA cautions “urinary estrogen excretion by pregnant mares is widely variable” so it seems the Administration would like to see PMU alternatives.
Mare and Foal
What Can I Do?
Welfare groups are trying to help PMU horses by changing the industry. The ASPCA gives grants to equine rescue groups to encourage others to help horses, instead of buying bred horses. Gentle Giants Draft Horse Rescue is also committed to rescuing horses and finding them safe homes.
Find out more about the industry and what you can do to help here.