Comparison Suggests Estradiol May Be Less Risky Than Premarin

The Women’s Health Initiative study used estrogens derived from horse urine along with synthetic progestin (Prempro). Ever since the study findings were publicized, some physicians have wondered if a different type of estrogen might have given a different result. Estradiol is the most common estrogen compound women naturally produce before menopause.

Now a study conducted at the Group Health Cooperative in Washington suggests that women taking oral estradiol are less likely to develop dangerous blood clots in their veins than those on conjugated equine estrogens, also known as Premarin. They also had a slightly lower risk of heart attack, although this was not statistically significant. The researchers say their study needs to be replicated. If other teams find similar results, women may be better able to choose a less risky form of HRT to relieve menopausal symptoms.

[JAMA Internal Medicine, online Sept 23, 2013]

Many of our readers will be pleased to see that there is finally some comparative research. Many agree with MC, who wrote:

“Regarding hormones after menopause–

“For years (70’s, 80’s 90’s) Premarin was prescribed for this, and during the study Premarin was used. Thus this study gives info about Premarin, not about bio-identical hormones or other physiologic replacement.

“About 5-6 years ago, many doctors/gynecologists and women were pulled off their HRT suddenly because of a study release. At that time, most were on PremPro–a combination of premarin and progesterone–again not physiologic.

“Premarin comes from pregnant horse urine. That form of estrogen was made for horses, not humans. As a physician and student of nutrition I was appalled that its use was so widespread and so accepted for so many years.

“Presently many physicians are recognizing that hormone replacement is safe using the bioidentical forms. Many use compounding and often forms can be given topically or intra-vaginally. Serum levels of estrogen can be measured– BUT more importantly a gynecologist can tell on physical exam and under the microscope from a vaginal swab if there is adequate estrogen effect on that tissue. A small amount of estradiol can prevent hot flashes but not be in excess. No research has been done on this type of use. Presumably there would be fewer side effects like gallbladder etc since doses are much smaller. Don’t treat the lab test, treat the person.

“No one should count on a hormone to prevent heart disease or osteoporosis–regular exercise and preventative medical care in these areas is necessary. I share your concerns about the “osteoporosis drugs” because of serious side effects, and have refused them myself. Weight bearing exercise and good nutrition are treatment of choice for osteoporosis. Another societal idol– being too thin– can increase chance of osteoporosis.”

Women interested in non-hormonal approaches to calming hot flashes may be interested in our Guide to Menopause.