Valacyclovir (the better-absorbed cousin of acyclovir) targets herpes­viruses such as Epstein–Barr virus (EBV) and HHV-6. Because reactivated herpes­viruses are suspected drivers for a slice of ME/CFS and (possibly) Long COVID, some clinicians and plenty of patients have tested this off-label route.

Why People Try It

• Virus-reactivation hypothesis. Blood work in a subset of ME/CFS and Long COVID patients shows high EBV or HHV-6 titres; valacyclovir directly suppresses those viruses.

• Clues from early studies. A six-month trial in the “EBV-positive” ME/CFS subset improved left-ventricular heart function and Energy Index scores in 64 % of participants PubMed.

• New Long COVID pilot data. A 14-week open-label study combining valacyclovir with the anti-inflammatory celecoxib reported statistically significant drops in fatigue, pain and autonomic symptoms versus matched controls Respiratory TherapyBioSpace.

• Legacy case series. Dr Martin Lerner’s long-term cohort showed meaningful functional gains in many EBV-positive patients kept on valacyclovir (or valganciclovir) for 12–36 months Dove PressPMC.

What Patients Report

• Big wins — but only for some. Twitter/X threads and Health Rising stories describe “night-and-day” rebounds: energy back, brain-fog lifting, resting heart rate settling.

• Partial or no response. Others feel only modest relief, while some see nothing at all—even with confirmed viral reactivation.

• Sustainability questions. A few early responders relapse when they lower the dose or stop altogether, hinting that ongoing suppression may be necessary.

• Side-effects. Most tolerate the drug well; occasional reports mention nausea, headache, or creatinine bumps—usually solved by extra hydration and periodic kidney labs.

Add Your Voice 💬

Because large, placebo-controlled trials are still pending, patient reviews are the most practical guide we have right now. Whether valacyclovir propelled you toward normal life, gave a mild boost, or did absolutely nothing, sharing the specifics helps the next person make an informed decision.

What to include:

• Your diagnosis (Long COVID, ME/CFS, Fibro, etc.)

• Viral test results (EBV, HHV-6, none)

• Dose, duration, and any add-ons (e.g., celecoxib)

• What improved, what didn’t, and how long it lasted

• Side-effects (even “none” is valuable)

Scroll to the “Add Review” box above, type your story, and hit Post. You can post anonymously. Five minutes of honesty from you could spare someone else months of uncertainty. Thanks for paying it forward!