The most important hormone during a woman's active life is estradiol, but a woman in real balance is the result of a balance between estradiol, progesterone and testosterone. To give you an idea, even the receptors for estrogen (there are three: estriol, estradiol and estrone) and progesterone are the same, which shows how the levels of one affect those of the other and their actions. So make sure you maintain adequate levels of all three throughout your life, or the most varied signs and symptoms may appear.
However, who produces progesterone before the menopause? Predominantly the corpus luteum (“remnant” of the follicle, after the egg has been expelled), in the second half of the cycle. In other words, the use of contraceptives inhibits ovulation and thus inhibits the normal production of progesterone.
But almost all contraceptives come with progesterone, right? Wrong! They come with progesterone-like substances called progestins, which obviously won't have the same functionality as the progesterone produced by your body. This is because the molecules of these progestins have to be somewhat different from progesterone, or they wouldn't be patented by the laboratories. And your body easily recognizes this difference. For all these reasons, many women who use contraceptives soon show symptoms of a lack of progesterone, such as bloating, mood swings, sleep disturbances and so on.
In the climacteric (post-menopause), it is still important for most women to try to maintain adequate levels of estradiol and progesterone, but preferably with hormones that the body recognizes as structurally identical to its own. This is for the reasons explained above. After all, the pharmaceutical industry also produces estradiol “look-alikes”, which also don't bring all the benefits of your estradiol, because they are different from it in order to obtain patents.
In short, after all this explanation, my opinion: worry about maintaining good hormone levels throughout your life and, if you're going to replace hormones, prefer bioidenticals.
Cheers!
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