birth control
"I took this pills for 8 months and once I stopped taking it, acne 
suddenly became my biggest problem and half year later, I was diagnosed as PCOS and my doctor told me that I had to take birth control pills again! It is really tricky that a med used for curing an illness seemed the one that also lead me to this illness( My period was very regular in the past ten years before 
I took this pills) .  I switch to other brands anyway."