If you’ve ever Googled "acyclovir vs valtrex" you probably want to know which pill will stop a cold sore or genital rash faster. Both drugs belong to the same antiviral family, but they aren’t identical. Below we break down how each works, when doctors pick one over the other, and what you should watch out for.
Acyclovir is the older drug. It stops the herpes virus from copying itself by messing with viral DNA. You usually take it three to five times a day because your body clears it quickly.
Valtrex (valacyclovir) is basically Acyclovir with a little chemical tweak that makes it stay in your blood longer. That means you only need to dose it once or twice daily for the same effect. In head‑to‑head studies, Valtrex lowered outbreak time by about 1‑2 days more than standard Acyclovir.
If you hate taking pills all day, Valtrex wins on convenience. A typical prescription is 500 mg twice daily for an outbreak or a single 1‑gram dose to stop future ones. Acyclovir usually comes as 200 mg five times a day or 400 mg three times a day.
Cost can flip the decision. Generic Acyclovir is often half the price of Valtrex, especially if you use insurance. Some pharmacies offer discount cards that make Valtrex affordable, so check your local prices before deciding.
Both drugs share similar side effects: headache, nausea, and mild kidney irritation. Because Valtrex builds up in the body faster, people with kidney problems need a lower dose. If you’ve had trouble with Acyclovir’s stomach upset, Valtrex might feel easier on your gut.
When doctors prescribe long‑term suppressive therapy (daily pills to stop outbreaks), they usually start with Valtrex because the once‑daily schedule improves adherence. However, if you’re on a tight budget or have mild recurrent outbreaks, Acyclovir works just fine.
Bottom line: If you need quick relief and don’t mind taking several doses, Acyclovir is a solid, cheap choice. If you prefer fewer pills and can afford the price bump, Valtrex gives you stronger coverage with less hassle.
Always talk to your pharmacist or doctor before switching. They’ll check kidney function, other meds, and any allergies to make sure the drug you pick won’t cause trouble.
Now that you know the basics, you can ask your prescriber which option fits your lifestyle, budget, and health needs best.
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