Valtrex gives a higher blood concentration of acyclovir than taking acyclovir itself and dont need to dose as often. Acyclovir/zovirax can be dosed at 800mg multiple times per day. Valtrex 1-3 times per day but twice a day is normal plus depemds on the dose, if on high dose spread it out over the day.
Consider famvir also, it may have actions on other herpes viruses like cmv and hhv6. Usually dose 2 to 3 times per day. Half live of 4-6hrs from memory but has a 18 hr half life intracellularly. Also less risk of kidney stones with famvir compared to valtrex.
500mg twice per day is a common dose.