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Drug Info

Do you have to take valacyclovir forever?

How long you take valacyclovir depends on the type and frequency of your outbreaks, among other factors
Rebecca Rovenstine writer headshot
By | Jan. 24, 2025 Medically reviewed by Nicolle Melendez, PA-C
A hand holding a blue capsule: Do you have to take valacyclovir forever?

Key takeaways

  • Valacyclovir treatment duration depends on the condition it’s treating and your immune system.

  • You don’t need to take valacyclovir every day for the rest of your life, but you can reduce the frequency of outbreaks by doing so.

  • Valacyclovir can treat the herpes virus, including herpes simplex virus-1, herpes simplex virus-2, and herpes zoster.

In this article:

Valacyclovir, sold under the brand name Valtrex, is a prescription antiviral medication that treats herpes viral infections, including cold sores, genital herpes, and shingles. There is no cure for herpes, and those diagnosed with these conditions can experience outbreaks throughout their lives. One may be concerned about requiring valacyclovir daily for the rest of one’s life; however, this may not be necessary. 

We consulted medical experts to determine the standard valacyclovir treatment length, factors that influence treatment, how the prescription drug works, and potential side effects from prolonged use.

Do you have to take valacyclovir every day for the rest of your life?

“No, you don’t need to take valacyclovir every day for the rest of your life,” said Raj Dasgupta, MD, a quadruple board-certified physician by the American Board of Internal Medicine specializing in internal medicine, pulmonology, critical care, and sleep medicine. He added, “In fact, if you’re treating a cold sore outbreak, you may only need to take valacyclovir for one day.”

The length of time someone will need valacyclovir therapy depends on their immune system, the condition they’re treating, the frequency of recurrence, and the severity of their herpes outbreaks. 

There are two standard treatment options when it comes to valacyclovir. 

  • There is daily suppressive therapy, where a person takes the medication every day. This is recommended for those who have frequent outbreaks in order to reduce recurrence. 
  • There is also episodic treatment, in which a person only takes valacyclovir during a flare-up to reduce and resolve symptoms faster.

“The decision to use daily or episodic therapy is usually based on the patient’s personal preference and medical history,” explained Dr. Hannah Kopelman, a dermatologist at Kopelman Aesthetic Surgery and the host of the weekly Derm Club podcast.

What does valacyclovir treat?

“Valacyclovir is an antiviral medication that treats herpes-related conditions, including cold sores (herpes simplex virus-1), genital herpes (herpes simplex virus-2), and shingles (herpes zoster),” Dr. Kopelman said. “It works by preventing the virus from multiplying, which helps reduce the severity and duration of outbreaks.”

Cold sores (HSV-1)

The World Health Organization estimates nearly two-thirds of adults under 50 years of age have herpes simplex virus-1 (HSV-1) also known as herpes labialis, is more commonly known as “cold sores.” HSV-1 is  typically acquired during childhood. This type of herpes infection is characterized by small blisters around the mouth and lips.

While there are over-the-counter topical creams to speed up recovery, Valtrex (valacyclovir) is the go-to prescription treatment of many healthcare providers.

The valacyclovir dosage for the treatment of herpes labialis depends on the frequency of your outbreaks and whether you commonly have recurrent cold sores. Those who have 10 or more outbreaks per year will typically opt for suppression therapy and take 500 mg of valacyclovir each day. For episodic treatment, patients are recommended to take 2,000 mg twice in one day. 

How fast does valacyclovir work for cold sores?

Valacyclovir works best when taken at the first sign of cold sore symptoms. While your lesion won’t heal immediately after taking the medication, valacyclovir will help decrease the amount of pain and discomfort within the first 24–48 hours. While a cold sore typically lasts up to 10 days without treatment, those taking valacyclovir should notice them clearing up within two to three days.

Genital Herpes (HSV-2)

Herpes simplex virus-2, or HSV-2, is acquired from sexual contact and is often referred to as genital herpes. While not as prevalent as HSV-1, it’s still a common condition. It’s estimated that 519 million individuals from 15–49 years of age have this herpes simplex virus type. 

Valacyclovir is also the standard treatment for HSV-2. The valacyclovir dosage depends on whether it’s the first outbreak or a recurrent episode for the infected person. The immune system has not yet encountered this virus on the first outbreak, so for most individuals, the first time involves the most severe symptoms. The valacyclovir dose for the initial herpes outbreak is 1,000 mg twice daily for 10 days. The dose of valacyclovir for recurrent outbreaks of genital herpes is 500 mg twice a day for three days.

“Valacyclovir can also help reduce the chances of spreading herpes,” Dr. Dasgupta said.

Daily suppression therapy is recommended for those with frequent recurrences of outbreaks or for those wanting to lower their risks of transmission to sexual partners. Multiple studies throughout the years found that daily suppression therapy can reduce the risk of HSV transmission. Wearing condoms during sexual activity can also help protect a person’s sex partners from the spread of this HSV type. 

How long does it take for valacyclovir to work on genital herpes?

Valacyclovir begins working two to three days after the first dose for a genital herpes outbreak. It works best when taken immediately after the first sign of an outbreak. Valacyclovir helps decrease the amount of pain, burning, and discomfort experienced. However, the healing process for the blisters takes a longer time, with lesions clearing up in nine to 10 days.

Oral herpes

Oral Herpes can refer to either type of herpes simplex virus. While less common, it is possible to spread HSV-2 through oral sex, causing someone to have an HSV-2 outbreak in their mouth. In the same way, if someone with a cold sore (HSV-1) performs oral sex, they could spread HSV-1 to the genital area. The only way to distinguish between the two herpes virus infections is with lab testing from a healthcare professional.

Shingles (herpes zoster)

Herpes zoster, more commonly referred to as shingles, is caused by the varicella-zoster virus. While you might not recognize the name, the virus is extremely common and is also the cause of the highly contagious childhood virus chickenpox. 

The varicella-zoster virus is latent in the body after chickenpox clears up and can reappear in adulthood as shingles. Shingles causes a painful rash. While the exact cause of the reactivation is unknown, periods of stress and illness could be a factor. That means if you’ve had chickenpox, you could be at risk for shingles. 

The valacyclovir dosage for shingles is 1,000 mg three times a day for seven days. This treatment works best when taken immediately after the first symptoms of shingles appear.

How long does it take for valacyclovir to work on shingles?

Valacyclovir should begin working to reduce pain and burning sensations from shingles within two to three days after starting treatment.

Potential side effects of prolonged valacyclovir use

“Prolonged use of valacyclovir is generally well tolerated,” Dr. Kopelman said. However, she did mention there are potential side effects, which include:

  • Headache
  • Nausea
  • Abdominal discomfort

While rare, long-term use may lead to kidney issues, especially for those who already have kidney problems. Neurological toxicity is also a possible concern.

“Regular monitoring by a healthcare provider is advised if you’re on long-term suppressive therapy,” Dr. Kopelman said.

The bottom line

Valacyclovir does not need to be taken forever; however, those with frequent outbreaks can benefit from daily suppression therapy. The prescription antiviral drug works best when taken at the first sign of an outbreak of HSV-1, HSV-2, or shingles. If you’re unsure whether daily suppression therapy or episodic therapy is best for you, speak to your healthcare provider about a valacyclovir treatment plan that will best suit your needs.