Kudzu root compounds can affect neurotransmitters (including serotonin, GABA, and glutamate.) It has shown value in treating migraine and cluster headache. It is recommended for allergies and diarrhea.
Kudzu? Lol, I see that plant all the time, it's like trying to take over down here in south-eastern US. Never heard of it as a medication though, how did you acquire it?