Can natural progesterone cream be used instead of bcp to treat pcos and underlying symptoms like irregular menses?

No, it cannot: Progesterone cream does not address the issues that need to be dealt with in pcos. And also, depending on the progesterone, it may act more like an androgen, a male-like hormone. Natural Progesterone creams are not used for treating irregular menses. Please see your gyn or an endocrinologist for proper treatment. I am concerned that this cream can make things worse.