I was warned that my potassium level could dip and if it did, I would feel "weird" and to watch out for that. My experience instead was nausea. I actually wondered if I was pregnant after the first few weeks, okay not really, but the nausea did rival morning sickness. Still, I decided I could handle a little dizziness.
Then it started to mess with my cycle which was great because that month somehow my body bypassed it's cyclicatory PMS mood swing/depression, bonus! After the first month I was pretty happy with the side effects (the nausea was also making me want to eat less and I lost a few lbs). The next month, nausea was in full force and I couldn't keep my cookies down.
That's where I draw the line. No amount of puking makes any of that worth it, so I stopped taking them until I felt like myself again. They also did a great job of clearing up my face, which is why I began taking them again in a lower dose, and so far no nausea at all this time. Now I'm just praying it lasts.