Valaciclovir vs Aciclovir – Quick Guide

If you’ve been prescribed an antiviral, you might wonder whether valaciclovir or aciclovir is a better fit. Both drugs fight the same viruses—herpes simplex and varicella‑zoster—but they differ in how quickly they work, how often you take them, and what side effects you might feel.

Below you’ll find plain‑language answers to the most common questions: How do they work? Which one is easier to take? When does cost matter? By the end you should be able to pick the option that matches your schedule, budget, and health needs.

How They Work

Valaciclovir is actually a pro‑drug. After you swallow it, your body changes it into aciclovir inside the bloodstream. This means valaciclovir delivers more active drug with each dose, so you usually need to take it less often.

Aciclovir, on the other hand, comes as the active form already. Because it’s less potent per pill, doctors typically prescribe it three or five times a day for serious infections. For mild cold sores, a short five‑day course works fine.

The antiviral action is the same for both: they stop the virus from copying its DNA, which slows down the outbreak and helps your immune system clear the infection faster.

Practical Tips for Choosing

Dosing convenience. If you hate taking pills multiple times a day, valaciclovir wins. A typical dose for shingles is 1,000 mg twice daily, while aciclovir might require 800 mg five times a day.

Speed of relief. For cold sores, studies show valaciclovir can reduce healing time by about a day compared with aciclovir. The difference isn’t huge, but it matters if you need the sore gone fast for work or school.

Side effects. Both drugs can cause headache, nausea, and mild kidney strain. Valaciclovir’s higher concentration sometimes leads to fewer stomach complaints because you take fewer pills. Always tell your doctor if you have kidney problems; dosage may need adjustment.

Cost. Aciclovir is older and usually cheaper, especially as a generic. Valaciclovir can be pricier, but many insurance plans cover it well. Check your pharmacy’s price list before deciding.

Special situations. If you’re pregnant or nursing, aciclovir has the longest safety record, so doctors often stick with it. For people with weakened immune systems, valaciclovir’s stronger dosing may give a better shot at controlling severe infections.

Bottom line: if you value fewer daily doses and can handle a slightly higher price, go with valaciclovir. If you’re on a tight budget or need a medication with decades of pregnancy data, aciclovir is still a solid choice.

Whatever you pick, start the treatment as soon as symptoms appear. Early use cuts down on pain, speeds healing, and lowers the chance of spreading the virus to others.

Still unsure? Talk to your pharmacist or doctor. They can look at your medical history, insurance coverage, and the specific infection you’re fighting to give a personalized recommendation.