Reading the threads on here it strikes me that progesterone often causes more trouble than it's worth and I wondered why the medical profession is so adamant on making women take progesterone with oestrogen. I undestand it's to do with preventing thickening of the endometrium and thus avoiding potential cancer, but I came across a reference to cancer in this event being very rare. On a par perhaps with developing breast cancer with the use of oestrogen? Low risk in other words.
Does anyone have any details as to why progesterone is considered so necessary? Or indeed, what are the odds on getting cancer or some other negative outcome as a result of not taking it? Am I missing something here?
I'm just curious really, but having worked my way through quite a selection of HRT combinations trying to find one that helps me, I suffered all sorts of side effects which could only have been the progesterone element, so I'd be interested to know why it's required.
Thanks 
LL
Hi Lamplighter - in the case of oestrogen and the endometrium, there is a proven causal link between over-thickening and cancer, and while rare it may still occur. There have been studies in the past giving the percentage of women who develop endometrial hyperplasia ( which can lead to cancer if untreated) on different oestrogen and progesterone doses although it is not possible to quantify the individual risk.
The problem is that with such build up the endometrium may start to break up spontaneously and shed, leading to heavy and irregular bleeding.
The extent to which the lining builds up is dependent on the oestrogen dose as well as the individual woman so for example there is (or was) an ultra-low patch (maybe still available) in US called Menostar (12.5 mcg) which was prescribed without progesterone although even in this case an annual progestogen course was recommended just to clear out any build up of lining.
Another option to minimise progesterone is to take it on a long cycle - which of course must be done under medical supervision. I am on such a cycle although mine is not very long - I now only extend the standard cycle by 2 weeks ie 6 week cycle but some women take progesterone every alternate month. Of course this only works if post-menopausal because otherwise your natural cycle could get in the way although some specialists argue that if you ovulate naturally then you are producing plenty of your own progesterone.
I hope this doesn't sound confusing?
Hurdity x
