Progesterone has been both ignored and mistakenly blamed for side effects it does not cause. How did that happen?
For one thing, progesterone was discovered shortly after estrogen. Thus, missing out on the tidy hormone dichotomy of “testosterone for men and estrogen for women,” pointed out endocrinology professor Jerilynn Prior. Also, progesterone could not (at first) be made into a medication that could be absorbed orally.