Valacyclovir and Acyclovir are both used for herpes simplex, zoster and suppressive therapy, but they differ on onset, duration and tolerability. Here is the practical comparison.
Valacyclovir vs Acyclovir
| Factor | Valacyclovir | Acyclovir |
|---|---|---|
| Class | nucleoside antiviral prodrug | Same therapeutic goal, different pharmacokinetics |
| Onset | lesion healing accelerates within 48 hours of onset | Comparable or slower depending on formulation |
| Duration | 12–24 hour dosing | Differs: the main reason clinicians switch |
| Strengths | 500 mg, 1000 mg | Separate titration ladder |
| Typical tolerability issue | headache | Class-typical, usually mild |
| Generic availability | Widely available from GMP manufacturers | Widely available |
Key takeaways
- Choose Valacyclovir when the priority is steady, sustained cover.
- Choose Acyclovir when tolerability or dosing convenience matters more.
- Both are available as quality generics, so cost is rarely the deciding factor.
- Switching within class does not usually require a washout period.
Which patient suits which
Patients who want on-demand control and a short exposure window generally do better on Valacyclovir. Those who prefer fewer decision points, or who did not tolerate the first option, usually move to Acyclovir. Both are prescribed for herpes simplex, zoster and suppressive therapy and both need the same contraindication check: significant renal impairment needs dose reduction.
Supply-side view
For pharmacies and telehealth platforms, stocking both gives prescribers a switch option without a re-order delay. ShiningRX ships Valacyclovir and Acyclovir together on one consignment to reduce freight cost per unit.
Valacyclovir at a glance
| Attribute | Detail |
|---|---|
| Drug class | nucleoside antiviral prodrug |
| Common brand | Valtrex |
| Licensed use | herpes simplex, zoster and suppressive therapy |
| Available strengths | 500 mg, 1000 mg |
| Dosage form | film-coated tablet |
| Typical onset | lesion healing accelerates within 48 hours of onset |
| Duration / dosing interval | 12–24 hour dosing |
| Storage | below 30 °C |