Why progesterone supplementation in natural cycle?


If the purpose of progesterone supplementation is to offset the diminished level of LH due to ovulation suppression in a medicated cycle, then what is the purpose of it in a natural cycle where ovulation was allowed to occur naturally?



Honestly, I think it’s an “it can’t hurt” sort of thing. I was on progesterone for all of my IUIs and I have a normal length luteal phase and all that, but to me it was like insurance. I’ve also heard (though I’m not sure if this is medically true) that embryos can implant late, and I hated to think that my corpus luteum would stop making progesterone and trigger AF before a potentially late implater was ready to take over progesterone production.