Help for my Sister

So my sister's started taking a progesterone only pill that doesn't have a sugar pill break in it. Feanolla is the name on the box. Anyway, what's people's experience with pills like this? she's finding that it makes her overly emotional, not good since she's starting a 2 month trip soon, but the doctor she saw yesterday told her it was all in her head bc there was no difference between the control group and pill taking group in the trials. I have no experience/actually knowledge on this so can anyone here give their opinion for her pls? 💕💕