"i have used valerian off and on for 26 years, no major side effect, at low doses. usually i used this herb for insomnia which it works well. also can be used for anxiety and stress; again at a low dosage. i would recommend on line information for your questions plus herbal specialists in your community. do not  exclude your doctor a md or equally qualified professional. i am now adding valerian at night in conjunction with 
zyprexa and klonapin.   zyprexa at 15 mg on e pill, klonapin at 0.50 or 1 mg dose.  do not recommend this combination yet to anybody. i am in the experimental phase.  stormy1959"