famvir is the same thing as valtrex: acyclovir. their both pro-drugs, so eventually they are both broken down to the same chemical. if valtrex doesnt work for you, famvir probably wont help much either. some people, such as myself, just dont respond to acyclovir antivirals. but you can try it. i recommend using something else. i take Lauricidin (monolaurin) and have just started LarreaRX (larrea tridentata). look into them.