Does Metformin help to lengthen the luteal phase when you have PCOS?

Question

I have been taking it for about 3 months now and noticed my luteal phase has lengthened. I know it's supposed to help with ovulation in women who are insulin resistant.

Answer 1

I think it is more likely that the luteal phase will come back to what is "normal range" for you (either shorten or lengthen it depending on how long is your cycle and whether you have PCOS or not).  In theory, metformin helps bring back the hormonal balance (and since ovulatory stage is tied to the follicular stage, it means it can regulate both parts of your cycle).  

For example, if you are producing more follicles by taking metformin (i.e. higher fsh/estrogen hormone), then by default the luteal phase can go up (since higher progesterone levels with more follicles).