Zovirax (acyclovir) is an antiviral drug used to treat infections caused by herpes viruses — most commonly cold sores, genital herpes, shingles (herpes zoster), and chickenpox. It doesn’t cure the virus, but it slows viral growth so outbreaks heal faster and symptoms get milder. You’ll find it as a cream, oral tablets or capsules, and an IV form in hospitals.
Start treatment as soon as you notice symptoms. For cold sores, applying the cream at the first tingle helps most. For genital herpes or shingles, oral acyclovir works best when started within 48–72 hours of symptoms. Typical adult oral doses vary by condition: for a first genital herpes episode doctors often prescribe 200 mg five times daily for 10 days, or 400 mg three times daily. For shingles, common dosing is 800 mg five times daily for 7–10 days. Your doctor will pick the exact dose based on your situation and kidney function.
Use the cream exactly as directed — apply a thin layer to clean, dry skin and avoid touching your eyes. If using oral tablets, take with a glass of water and maintain good hydration, especially if you have kidney problems. IV acyclovir is reserved for severe infections or patients who can’t take pills.
Most people tolerate Zovirax well. Common side effects include nausea, headache, and mild skin irritation with the cream. Less common but serious effects include kidney problems and confusion, especially in older adults or people with reduced kidney function. Drink plenty of water while taking oral acyclovir to help protect your kidneys.
Tell your clinician about other medicines you take. Acyclovir can interact with some drugs that affect kidney function or compete for the same pathways. If you’re pregnant or breastfeeding, talk to your provider — topical acyclovir is often considered low risk, but oral or IV use needs a medical check.
Resistance to acyclovir is rare in healthy people but more likely in immune‑suppressed patients. If outbreaks don’t respond or keep returning despite correct use, your doctor may test for resistant virus and suggest alternatives.
Practical tips: keep the cream sealed and store tablets at room temperature away from moisture; finish the full course your doctor prescribes; don’t share personal items like lip balms or towels during an outbreak; use condoms to lower genital herpes transmission risk but know they don’t eliminate it.
When to call a doctor: high fever, spreading rash, severe pain, signs of kidney trouble (less urine, swelling), or sudden confusion. For routine outbreaks, early treatment shortens recovery and eases symptoms — so don’t wait for the lesion to worsen.
If you need help finding a legitimate pharmacy or have questions about dosing, ask your healthcare provider or pharmacist. Zovirax is a well-known, long‑used option for herpes care when used correctly and under guidance.
Zovirax is a top choice for anyone dealing with pesky cold sores or herpes outbreaks. This article explains how Zovirax (acyclovir) works, the best ways to use it, who benefits most, and why it stands out among antiviral creams. Expect real facts, tips, answers to questions people actually have, and a street-smart look at how to get the most from this antiviral heavyweight.
View more