Progesterone, Flushes and Your Heart

Confusing synthetic progestins found in HRT with bioidentical progesterone has led to some wrong assumptions about the effectiveness and safety of the hormone and hidden its real benefits to women.


A study from a research team at the University of British Columbia has clarified a real confusion among women, and also many of their doctors.

We have known for many years that oestrogen and the synthetic progestins increase the risks of heart attack and stroke and this is one of the reasons why long term use of HRT is discouraged.

Unfortunately there was also a widespread assumption at that time that natural progesterone would have the same risks because of its molecular similarity to progestins, what they failed to see were the very real differences between the two.

The late Dr John Lee, the pioneer of natural progesterone cream usage, likened it to having a key cut: the progestin key goes in the lock but does not open the door, but bioidentical progesterone is recognised by the body as a genuine key and the door to hormone balance is readily opened.

Progesterone is safe for heart health, and effective for flushes and night sweats

This study confirmed that treatment with progesterone was shown to alleviate severe hot flushes and night sweats with no cardiovascular risk.

This is no surprise to bioidentical doctors who know progesterone’s role in actually supporting heart health and effectively reducing menopausal symptoms but this study makes positive reading for everyone interested in the effectiveness of bioidentical hormones.

The study was conducted by Dr. Jerilynn C. Prior, a professor of endocrinology and the head of Centre for Menstrual Cycle and Ovulation Research and who was a colleague of Dr John Lee.

Why HRT is not the answer

HRT has been the preferred way for doctors to deal with menopausal symptoms using a combination of synthetic oestrogen and synthetic progesterone (progestins) to reduce the frequency and severity of hot flushes and night sweats, as well as to prevent osteoporosis.

However many women find themselves unable to tolerate it, and the ongoing research over this period has shown that it increased the risk of heart disease and strokes plus breast and other hormonal cancers.

HRT formulas included a progestin (not progesterone) to guard against a thickening of the endometrium which could lead to uterine cancer.

Women who have had a hysterectomy were given oestrogen-only HRT which has led to more problems as they are having unopposed oestrogen and no protection from progesterone at all and so the increased risk of heart disease and breast cancer still remains.

This is one reason why HRT use is now recommended for no longer than 2-5 years.

The trial outcome

The three month trial took 110 women and gave half a placebo and half progesterone  and the researchers used each woman’s age and changes in blood pressure and cholesterol levels to calculate their 10-year risk of a heart attack and other blood vessel diseases. There was no increased risk between those taking progesterone and the control group. Dr Prior commented

“Many women are apprehensive about taking progesterone for hot flashes because of a belief that it carries the same – or even greater – risks than oestrogen. We have already shown that the benefits of progesterone alone have been overlooked. This study demonstrates that progesterone’s risks have been overblown.”

Dr Prior has been prescribing progesterone since it became available in Canada in 1995, for postmenopausal women to treat flashes and night sweats, and for peri-menopausal women to alleviate hot flashes, heavy menstrual flow and sore breasts.

Helpful information:

Hot flushes are one of the major symptoms that can make menopause a misery. Women with a history of heart disease are discouraged from HRT, but this has led to them thinking that progesterone also may not be helpful.

The reverse is shown to be true as bioidentical hormones do not carry the same risks as conventional HRT and certainly bioidentical progesterone can safely be used to control hot flushes and the oestrogen dominance that is also common at menopause.

If you are concerned about your heart health, then diet also has a major part to play and this article has some helpful information on what not to eat.