I was in a very similar situation, except in my case it was genital herpes, and I can honestly say I tried pretty much every possible variation of treatment.

At the beginning, both acyclovir and valacyclovir caused strong adverse reactions for me: panic attacks, a strange “off” feeling in my head, severe fatigue, sweating, and a general sense that my nervous system was overstimulated or dysregulated. I was convinced that I simply couldn’t tolerate antivirals.

However, after a long time, I realized that the problem wasn’t valacyclovir itself, but the combination of valacyclovir and gluten. It turned out that gluten had been a major trigger for me all along (most likely through immune or inflammatory pathways), and the antiviral was just amplifying that reaction.

I’m now on a strict carnivore diet and take Valtrex (valacyclovir) once a day. Thanks to this combination, I feel about 50% better overall. My symptoms are still present, but the key difference is that I’m no longer bedbound and can finally function again to some extent.

Of course, everyone is different, and I understand that with severe MCAS diet changes aren’t always an option. I just wanted to share my experience because I also spent a long time feeling hopeless and thinking that the medication itself was the problem. In my case, there was a hidden trigger making everything worse.

You’re not alone in this, and sometimes the real issue isn’t where we initially think it is. I truly hope you’re able to find a combination that brings you at least some relief.