Here’s The Current Thinking On Hormone Therapy (It’s Not What You Heard 20 Years Ago)
Posted on April 21, 2022
Over twenty years ago, the Women’s Health Initiative (WHI) study, which randomized women to receive either hormone therapy or a placebo, set out to assess the benefits and risks of hormone therapy. In 2002, the WHI study was abruptly halted because the researchers found that women taking a combination of estrogen and progestin had an increased risk of breast cancer, heart attacks, stroke, and blood clots. Headlines blasted the news that hormone therapy was unsafe, and the use of hormone therapy in the United States plummeted by about 80%.
Later analysis of the WHI study data focused on the age of the participants. This analysis found that primarily older women were at high risk from the use of these hormones, and that the benefits of hormone therapy generally outweighed the risks for healthy women who are under 60 years old and within ten years of the onset of menopause. Despite the good news, many women and doctors are still relying on the original warnings to guide their decisions regarding hormones.
An 18-year follow-up study of the participants in the WHI study provides more reassurance on the safety of hormones. The report found that women who took hormones did not have a greater chance of dying in the subsequent 18 years than those who did not. The researchers report in JAMA that hormone therapy use (estrogen alone or estrogen plus progestin) for five to seven years “was not associated with risk of all-cause, cardiovascular, or cancer mortality during a cumulative follow-up of 18 years.”
In the same article, the authors conclude, “Observational studies, which include primarily women who initiate hormone therapy in early menopause, have generally demonstrated lower mortality among women using hormone therapy compared with nonusers.” In other words, according to these studies, women who started hormone therapy in early menopause tended to live longer than women who didn’t take hormones.
In fact, a pooled statistical analysis of thirty clinical trials found that women who began hormone therapy before age 60 had a 39% lower risk of death than women who didn’t take hormones.
With all of this new information, why is there still so much resistance surrounding hormone therapy? JoAnn Manson, a Harvard Medical School professor at Brigham and Women’s Hospital and one of the lead researchers on the WHI study, says it’s been difficult to get the word out about follow-up studies showing that benefits outweigh risks for younger women with menopause symptoms.
“There were all these alarm bells that went off in 2002. And once a bell is rung, it cannot be unrung,” Manson explains. “It's taking a very long time to make it clear that there were differences by age and that hormone therapy is still an appropriate treatment for women in early menopause who have moderate to severe symptoms. The results are all out there in prominent journals read by clinicians,” she says.
Newer formulations of hormones, not widely used when the WHI study began, may further minimize risks. Manson says that preliminary data from studies examining these newer hormone formulations including transdermal estrogen (delivered through the skin via a patch) and micronized progesterone are promising. Transdermal estrogen doesn't go through the liver and may also reduce the chances of blood clots and stroke compared to oral estrogen. And Bluming and Tavris write, “When women take estrogen combined with natural, micronized progesterone, no increased risk of breast cancer has thus far been observed in any study.”
Although some of these new FDA-approved formulations are promising, all of the experts I spoke to caution against the use of compounded hormones. Compounded hormones are not regulated by the Food and Drug Administration (FDA), and these compounds have not been shown to be safe or effective and can have impurities and inconsistent dosing. As evidence of the lack of reliable information available to women, 35% of women currently on hormone therapy take these unregulated compounds. How do you know if your hormones are compounded? If the hormones are produced by a pharmaceutical company that is recognized and approved by the FDA, then they are not compounded.