Valtrex and Famvir do not have any efficacy against HHV6. Only Valcyte has partial efficacy against it. You have to do very regular liver function tests. There are some side effects and possible long-term effects.
Herpes antivirals, if they are going to work at all, take many months before you start noticing any improvements, and require even up to a couple years of daily treatment to gain significant permanent improvements. It’s a marathon.
They also require a pretty strong policy aggressive rating and pacing, minimizing PEM, and no crashing. My personal opinion, but if you are still working a lot and doing all that exertion it’s more likely than not that they will be a waste of effort and time given the testimonials of pwME for whom they did and didn’t work.
See this page for Dr. Lerner’s Valcyte protocol
https://www.healthrising.org/treati...nciclovir-for-chronic-fatigue-syndrome-mecfs/