Metformin is a very well studied medication, there are more studies in Metformin than any other drug regarding PCOS. First of all, Metformin is a medication that is mainly used in diabetes. The way that it is used in polycystic ovaries is that it actually reduces the insulin resistance. It makes the body more sensitive to insulin. So, it reduces the insulin and by this mechanism both centrally, in the brain, and locally, in the ovaries, it can reduce the androgen. It can help with weight control, which is very important for people with PCOS because the vast majority of them have got a weight problem as well. Of course, it is not working by itself. It has to be associated with the actual weight loss. In the initial stage, Metformin can act very well, and it can stimulate the ovulation. The latest research and meta-studies showed that it is worse than Clomiphene or Letrozole if it is used by itself. Also, the new studies point out that the combination of Metformin and Clomid does not change significantly the acting of Clomid. I would say this is not the first-line medication unless somebody wants to try by themselves without follicular tracking, without actually having controlled ovulation and just wants to help the body ovulating better and controlling the cycle. It is recommended mainly for women who are obese and who suffer from insulin resistance. I wouldn’t use it for women who are not insulin resistant or lean. It could be used as a second-line medication if someone is resistant to Clomiphene, but not because it will significantly change the live birth rate, but because it can produce more follicles. If we increase the dose of Clomid, we risk that there can be two or more follicles and if we add Metformin, we can make things better, and we can have just one follicle. Metformin, however, could be used, and there is support in research for that, in pre-treatment for IVF, because it can reduce the risk of hyperstimulation. It does not decrease the miscarriage rate, we are not sure that it helps with the live birth rate, but it can help with hyperstimulation in IVF.