How (quickly) do these pills work?

Valacyclovir (aka Valtrex) & Acyclovir (aka Zovirax and Sitavig) are the most effective drugs on the market today for treating cold sores, shingles and genital herpes outbreaks. They are also used to treat chickenpox (VZV).

They are both considered equally effective for preventing outbreaks & the spread of Herpes Simplex 1 & 2 to sexual partners.

The most important thing to preventing an outbreak is time. Within the first 48 hours of feeling the first symptoms in the area you're treating (itchiness, tingling, burning, pain) is recommended.

However, the quicker you take valacyclovir or acyclovir after feeling the first symptoms, the less likely you are to experience an outbreak. 

For primary herpes outbreaks (first time)

For valacyclovir, 1000mg twice a day for 10 days is standard. For acyclovir, 800mg twice a day for 5-10 days.

The first is the worst. This is usually the worst outbreak you'll ever get - it hurts the most & last the longest - because it's the first time being introduced to your body. In addition, you won't really know what to look for. But remember, take the pills as soon as you feel any of the above symptoms to reduce the outbreak's standard 10 day (or longer) course . 

For recurring herpes outbreaks (episodic)

For valacyclovir, 500mg twice a day for 3-5 days is standard. For acyclovir, 800mg three times a day for 3-5 days.

Once HSV-1 and/or HSV-2 has been exposed to your immune system, you'll likely have less (severe) outbreaks. On average, people with HSV-1 experience about one outbreak per year, while people with HSV-2 will usually experience four to five outbreaks per year. Additionally, you'll better understand the early symptoms and what to expect so that you can minimize and better prevent outbreaks. 

For recurring herpes outbreaks (suppressive)

For valacyclovir, 500-1000mg daily. For acyclovir, 800mg daily.

Taking a dose every day has been proven to be the most effective way to prevent outbreaks. Obviously there are pros and cons to this approach (severely reducing the chance of an outbreak vs. taking a pill everyday, etc.), but it's important to note that this option is available for a wide range of outbreak frequencies- not just those who have more than 6 outbreaks per year. However, It's important to talk to your physician to find out the best treatment plan for you.

For cold sores

For valacyclovir, it's 2000mg twice a day for 1 day. For acyclovir, it's 2400mg twice a day for 1 day. 

Valacyclovir for Shingles

For valacyclovir, 1,000 mg three times a day for 7 days. For acyclovir, 800mg five times a day for 7-10 days.

For men too?

Yes, our doctors treat all human beings. You can check out our guys site here.

Remember, the quicker you take it, the less severe (if at all) the outbreak.

If you feel anything coming on, talk to a doctor to see if valacyclovir or acyclovir are right for you.


The views expressed in this article are intended to introduce alternative studies and provoke conversation. They are the views of the author for informational purposes only; not necessarily those of wisp, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.