I'm currently working 7 days a week at two different places so I decided to try the new V8 energy drinks. I don't normally drink anything with caffeine in it... Well two weeks after drinking these every morning my period had hit me... hard. I was sent home from both jobs on Friday. I took my pain killers & was in tears the entire day. Turns out for people that aren't used to consuming caffeine it can cause an extreamly heavy flow & extream pain. I've never been in so much pain from my period before. So if you're a noncaffiene drinker don't start or continue while on your period or be ready for a world of hurt.