jimells, Valtrex is quite safe (as antivirals go) and has a relatively low side effect profile. It has been used as a long-term prophylactic medication for genital herpes for 10 years or more, so there's a lot of experience with long-term Valtrex use without serious side effects. This is why some docs are willing to prescribe it for chronic HHV-6 even though it's not particularly effective for that. Valcyte is much more effective for chronic HHV-6, but has much more serious potential side effects so the patient needs to be carefully monitored. Many docs are afraid to use it for that reason. And it's absurdly expensive...... speaking of absurdly expensive, are you sure you aren't taking Valcyte? Valtrex is not ordinarily that expensive, I think. Relatively speaking, of course. Antivirals aren't cheap in any case. Daughter and I have been taking Valtrex at a high dose for a couple of years now to keep HHV-6 and EBV suppressed once we got them back into latency with Valcyte. Neither of us has had any side effects from Valtrex.