Took phentermine diet pill 2 yrs. Ago for 6 months. A month after I quit my mentrual cycle stopped. Went to the doc. They put me on provera. Well the doc. Said it wasn't the phentermine that did it. So I started taking phentermine again and 3 months into taking it my mentrual cycle suddenly stopped again 4 pregnancy test negative. So what would cause this to happen? Before all this ever since I was 10 yrs. Old it was very regular. And 22 yrs. Old now. If it's the diet pill I will stop taking it right away cause I do want to have kids sometime in my life.

As far as I know, there's nothing in the pill itself to affect your period, but if you lose weight very quickly, that can affect your mentral cycle.