The sex hormones oestrogen and progesterone are all steroids. They are closely related to the anabolic steroids which some athletes have used as body builders. HRT contains the same combinations of oestrogens and progestogens which make up the Pill. The difference between the Pill and HRT lies in the difference in the oestrogens by dose and chemical structure. Most of the combined oral Pills contain ethinyl oestradiol which is a synthetic oestrogen whereas those used in HRT are usually referred to as ‘natural’. ‘Natural’ in this instance means that they have been extracted from pigs’ ovaries or pregnant mares’ urine, a substance particularly high in oestrogen, (hence the name Premarin, one of the best-selling HRTs, and also Prempak C). Not all the oestrogens in the mixture are natural to humans and some can behave like ethinyl oestradiol, the synthetic hormone, which tends to affect liver metabolism by producing changes in blood clotting and blood fat levels. The progestogens used in the Pill and HRT are the same, but in HRT the progestogen is only given for ten to twelve days of each cycle. Because of the close similarity between the Pill and HRT it is not surprising that many of the side effects reported by women – water retention, weight gain, headaches and depression – are the same.
Some women stopped taking HRT when disturbing reports appeared in the media about its production. In 1995, a representative of the World Society for the Protection of Animals (WSPA) was part of a team which inspected thirty-two farms in Canada, all of which were contracted to supply mare’s urine. The following passage is extracted from WSPA’s report, HRT, published in 1996:
‘…after mares have become pregnant, they arc brought into barns and housed in individual stalls. A harness-type device… is attached to the animals’ rear quarters so that their urine can be collected. The horses spend most of the next six months in these stalls while their oestrogen-rich urine is collected.
Often the horses’ stalls were too small to allow the animals to lie down comfortably. In nearly all of the farms visited, our inspector saw tethers that were so short that mares were unable to lay their head on the ground… In all but a few farms, water was being restricted…it is suspected that this is practiced in order to ensure that urine has a high concentration of oestrogen.’
WSPA’s findings from the visit were shared by other members of the inspection team which included an expert from the Royal School of Veterinary Studies in Edinburgh, which also published a report, Report of Findings During Visit to Pregnant Mare’s Urine (PMU) Farms, Saskatchewan, in which it described the stalls in most barns as ‘totally unsuitable for horses…’.
Since this 1995 inspection, Edinburgh University has reported that,
‘Wyeth -Aycrst [the company which makes Premarin] has announced that changes have been made at certain farms and that veterinary supervision has been stepped up. However, the company has refused to allow WSPA, as well as local animal welfare inspectors, to re-visit any of the farms…
Adult horses are not the only ones to suffer in the production of Premarin. For every pregnant mare…a foal is born each year. Most of these young animals are of little value to the farmers. Each year thousands are sold off cheaply and fattened up at giant feed lots before being slaughtered. Many end up on dinner plates in Japan or Europe or are used to make dog food.’
Other organization that are concerned about the treatment of these horses include: PETA (People for the Ethical Treatment of Animals); The Humane Society of the United States; the RSPCA; and the University of Edinburgh’s Department of Veterinary Clinical Studies. Both WSPA and PETA have information packs which are available by post.