Always a dull headache during session

Hi all, I'm fairly new to kava but have been drinking for a few months now. I believe I've found the right amount to drink per night which gives me a good buzz, however no matter how much I drink I always sit there with a dull headache at the back of my head. I always have my sessions with gatorade and i take a few sips of that after a sip of kava. So I know I should be hydrated. I do drink micronized kava without straining so I'm guessing its related to that?