According to the new KEEPS study, modern types of HRT such as low-dose oestradiol and micronised progesterone (natural progesterone) are SAFER than the HRT used in the WHI study 10 years ago.
The old style of HRT has heavily dosed horse oestrogen and medroxyprogesterone (Provera). Toxic, nasty drugs. The small doses of bio-identical oestradiol and progesterone used in the KEEPS study are a very different thing (so no wonder they gave such different results!). The KEEPS study hormones provided significant relief for mood, libido, and flushes, and they appear to be safe - at least in the short term.
Another recent study found that 73% of Australian women who use natural progesterone find relief from irritability, foggy thinking, and sleep problems. (1)
Natural progesterone is effective for hot flushes
A 2010 study found natural progesterone to be effective for hot flushes. According to its lead author Dr. Prior,
"This is the first evidence that oral micronized progesterone, which is molecularly identical to the natural hormone, is effective for women with symptomatic hot flashes."
"Women improve very quickly on oral micronized progesterone," she said.
No serious side effects were noted. Progesterone may be suitable for women that cannot take oestrogen. (2)
Natural progesterone is safe
It was the synthetic progestin medroxyprogesterone (Provera) that made HRT unsafe in the 2002 Women's Health Initiative study. Micronised, natural progesterone is a very different thing and appears to have NO risk for heart disease or breast cancer. (3) According to one of the authors of the new KEEPS HRT study:
"One of the theories is that the form of progesterone used in WHI, medroxyprogesterone is very different than the form that KEEPS used, which is micronized progesterone, the more natural form of progesterone. We certainly did not see any adverse effects with this type of progesterone, and it was used in a cyclical fashion, not given every day as was Provera in the WHI."
Natural progesterone has been used in France and other parts of Europe for many decades. It has a well-established safety record there.
The "E3N cohort study" is a French health study that is following over 100,000 menopausal women over many years. It has provided some interesting information about HRT and the benefit of natural progesterone (micronized progesterone) vs conventional progestin. First of all, the E3N study found that unlike progestin, natural progesterone does not increase the risk for breast cancer. (4) Results from the E3N study are that micronized progesterone is far safer than progestins when it comes to cardiovascular disease. Unlike progestins, which are a stroke risk, micronized progesterone may actually reduce the risk for stroke. (5)
Natural Progesterone is transitioning into standard hormone treatment.
"Natural Progesterone" is transitioning into standard hormone therapy. Of course, once it's standard, it won't be called natural anymore, but that's OK! Whether it's called natural progesterone or it's official name micronised progesterone, it is still a safe, effective treatment. Long overdue.
The same change has already happened with oestrogen. Only 10 years ago, horse oestrogen tablets were the standard. Horse oestrogens were rife with side effects and cancer risk. Now, most doctors are happy to prescribe the safer and gentler bioidentical oestradiol in a patch or gel used in the KEEPS study.
Natural progesterone is effective for oestrogen dominance
Natural progesterone also alleviates symptoms of oestrogen dominance such as heavy periods, PMT mood swings, fluid retention before the period, breast tenderness, fibroids and weight gain on the hips.
Natural progesterone is also effective for:
How much progesterone should be used?
As Naturopaths, we recommend a low-dose approach to natural hormones. We recommend that you use the minimal dose of progesterone (10-20mg per day). That is about what the ovaries would make in a normal menstrual cycle. Some doctors prescribe up to 10x this amount, but that can do more harm than good, because excess progesterone converts to oestrogen, and may cause the very oestrogen dominant symptoms that you're trying to treat.
- Spark MJ et al. Compounded progesterone: Why is it acceptable to Australian women? Maturitas. 2012. 73(4):318-24. PMID: 23039945
- Hitchcock CL, Prior JC. Oral micronized progesterone for vasomotor symptoms--a placebo-controlled randomized trial in healthy postmenopausal women. Menopause. 2012. 19(8):886-93.
- Manson JE, et al. New findings from the Kronos early estrogen prevention study (keeps) Randomized trial. NAMS 2012. 23rd Annual Meeting. Presented October 3, 2012
- Fournier, A et al. Breast cancer risk in relation to different types of hormone replacement therapy in the E3N-EPIC cohort. Int. J. Cancer 2005: 114: 448-454
- Canonico M, Fournier A, Carcaillon L, "Postmenopausal Hormone Therapy and Risk of Idiopathic Venous Thromboembolism: Results From the E3N Cohort Study," Arteriosclerosis, Thrombosis, and Vascular Biology. 2010;30:340.