Welcome to healthcare Magic.
This drug has a known side effect of weight gain & edema due to fluid retention. Which may be reversible after discontinuation, if you lead a healthy life style otherwise .
It may also effects periods & may even cause absence of periods. This effect is also reversible once you discontinue the drug ( if this medicine is the sole cause of your period irregularity otherwise you need a Gynecologist consultation).
I hope you know that females of childbearing age who are sexually active, should employ non-hormonal contraception
throughout the course of this treatment.
I don't know your exact diagnosis & what type of cyst
you have. I hope you have started this medicine on prescription of a qualified Gynecologist & not taking it on advise of a friend as it's use may not be allowed in undiagnosed ovarian masses.
Periodic tests of liver
function and complete blood count
should also be considered during it's use.
Hope I have answered your questions properly.