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Valacyclovir (Valtrex): Uses, Side Effects and Dosage

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Prescription (Rx)
Strength:
500 mg, 1 g
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Source: FDA drug labeling via NLM DailyMed · About this document

Patient information: uses, side effects, how to take - Valacyclovir

What are valacyclovir tablets?

Valacyclovir tablets are a prescription medicine used in adults:

  • to treat cold sores (herpes labialis).
  • to treat or control genital herpes outbreaks in adults with normal immune systems.
  • to control genital herpes outbreaks in adults with human immunodeficiency virus-1 (HIV-1).

  • with safer sex practices to lower the chance of spreading genital herpes to others, in adults with normal immune systems. Even with safer sex practices, it is still possible to spread genital herpes.

    • Do not have sexual contact with your partner when you have any symptom or outbreak of genital herpes.
    • Use a condom made of latex or polyurethane whenever you have sexual contact.
    • Ask your healthcare provider for more information about safer sex practices.
  • to treat shingles (herpes zoster) in adults with normal immune systems.

Valacyclovir tablets are used in children to treat:

  • cold sores in children 12 years of age and older.

  • chickenpox in children with normal immune systems 2 years of age to less than 18 years of age.

Valacyclovir tablets do not cure cold sores, chickenpox, shingles, or genital herpes.

  • It is not known if valacyclovir tablets are safe and effective in people with weakened immune systems, other than for control of outbreaks of genital herpes in people with HIV-1.
  • It is not known if valacyclovir tablets are safe and effective in people 18 years of age and older with chickenpox.

  • It is not known if valacyclovir tablets are safe and effective in children:

    • less than 12 years of age with cold sores
    • less than 2 years of age with chickenpox
    • less than 18 years of age with genital herpes or shingles

Do not take valacyclovir tablets if you are allergic to valacyclovir, acyclovir, or any of the ingredients in valacyclovir tablets. See the end of this leaflet for a complete list of ingredients in valacyclovir tablets.

Before you take valacyclovir tablets, tell your healthcare provider about all of your medical conditions, including if you:

  • have had severe skin reactions with valacyclovir or acyclovir.
  • have had a bone marrow transplant or kidney transplant, or if you have advanced HIV-1 infection or acquired immune deficiency syndrome (AIDS).
  • have kidney problems, including if you receive dialysis.

  • are pregnant or plan to become pregnant. It is not known if valacyclovir tablets will harm your unborn baby. You and your healthcare provider will decide if you will take valacyclovir tablets if you are pregnant.

  • are breastfeeding or plan to breastfeed. Valacyclovir hydrochloride may pass into your breastmilk. Talk with your healthcare provider about the best way to feed your child if you take valacyclovir tablets.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

How should I take valacyclovir tablets?

  • Take valacyclovir tablets exactly as your healthcare provider tells you to take it.
  • Your dose of valacyclovir tablets and length of treatment will depend on the type of infection that you have and any other medical problems that you have.
  • Do not stop valacyclovir tablets or change your treatment without talking to your healthcare provider.

  • Take valacyclovir tablets with or without food.

  • Tell your healthcare provider if your child cannot swallow valacyclovir tablets. Your healthcare provider can prescribe valacyclovir tablets as an oral suspension for your child.
  • If you are taking valacyclovir tablets to treat outbreaks of cold sores, chickenpox, shingles, or genital herpes, take valacyclovir tablets as soon as you have the first symptoms of infection such as tingling, itching, or burning, or when the sore appears.
  • It is important for you to stay well hydrated during treatment with valacyclovir tablets. Be sure to drink plenty of fluids during this time.
  • If you miss a dose of valacyclovir tablets, take it as soon as you remember. If it is almost time for your next dose, do not take the missed dose. Take the next dose at your regular time. Do not take 2 doses at the same time or take more valacyclovir tablets than prescribed.
  • If you take too much valacyclovir hydrochloride, call your healthcare provider or go to the nearest hospital emergency room right away.

What are the possible side effects of valacyclovir tablets?

Valacyclovir tablets can cause serious side effects including:

  • Thrombotic Thrombocytopenic Purpura (TTP) and Hemolytic Uremic Syndrome (HUS). TTP and HUS have happened in people with weakened immune systems taking valacyclovir tablets and have led to death. TTP and HUS are disorders that can cause small blood clots to form throughout the body and decrease blood flow to body organs such as the brain, heart, and kidneys. Your healthcare provider will stop treatment with valacyclovir tablets if you have signs or symptoms of TTP and HUS.
  • kidney failure.

  • nervous system problems. Tell your healthcare provider right away if you get any of these signs or symptoms of nervous system problems during treatment with valacyclovir tablets:

    • aggressive behavior
    • speech problems
    • unsteady movement
    • hallucinations (seeing or hearing things that are really not there)
    • shaky movements
    • seizures
    • confusion
    • coma
  • severe skin reactions. Severe skin reactions have happened in people treated with valacyclovir tablets. Tell your healthcare provider right away if you develop a rash during treatment with valacyclovir tablets. Stop taking valacyclovir tablets immediately and get medical help right away if you develop a painful rash with any of the following symptoms: blisters or sores in the mouth, or blisters or peeling of the skin.

Elderly people are more likely to get certain side effects. Talk to your healthcare provider if this is a concern for you.

The most common side effects of valacyclovir tablets in adults include:

  • headache
  • stomach (abdominal) pain
  • nausea

The most common side effect of valacyclovir tablets in children less than 18 years of age is headache.

These are not all the possible side effects of valacyclovir tablets.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

How should I store valacyclovir tablets?

  • Store valacyclovir tablets at 20o to 25oC (68o to 77oF).
  • Store valacyclovir suspension between 2º to 8ºC (36º to 46ºF) in a refrigerator. Throw away (discard) any remaining valacyclovir suspension after 28 days.
  • Shake valacyclovir suspension bottle well before using.
  • Keep valacyclovir tablets in a tightly closed container.

Keep valacyclovir tablets and all medicines out of the reach of children.

General information about the safe and effective use of valacyclovir tablets.

Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use valacyclovir tablets for a condition for which it was not prescribed. Do not give valacyclovir tablets to other people, even if they have the same symptoms that you have. It may harm them. You can ask your healthcare provider or pharmacist for information about valacyclovir tablets that is written for health professionals.

What are the ingredients in valacyclovir tablets?

Active ingredient: valacyclovir hydrochloride

Inactive ingredients: crospovidone, FD&C blue #2/indigo carmine aluminum lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, and titanium dioxide.

Manufactured for: Northstar Rx LLC

Memphis, TN 38141.

Manufactured by: APL Healthcare Limited

Unit-IV (MP SEZ),

Tirupati (Dt)-524421

Andhra Pradesh, India.

M.L.No.: 04/NLR/AP/2016/F/CC

This Patient Information has been approved by the U.S. Food and Drug Administration.

Revised: 04/2026

About this document

Source: FDA drug labeling via NLM DailyMed · Application number: ANDA 090682 · View the label on DailyMed

Revision date stated in the text: April 2026

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The information on this site does not replace the advice of a doctor or pharmacist.

Drug information for Valacyclovir

Rx or OTC
Prescription (Rx)?
  • This drug is available only with a prescription from a licensed healthcare provider.
  • Rx
Drug class Herpes Simplex Virus Nucleoside Analog DNA Polymerase Inhibitor, Herpes Zoster Virus Nucleoside Analog DNA Polymerase Inhibitor, Herpesvirus Nucleoside Analog DNA Polymerase Inhibitor
Active ingredient Valacyclovir hydrochloride
Dosage form Tablet, film coated
Route Oral
Marketing status listed in the FDA NDC Directory
Company (applicant) AUROBINDO PHARMA
FDA approval ANDA 090682Abbreviated New Drug Application (ANDA) – generic drug Approved May 24, 2010
Therapeutic equivalence (TE) code ABCodes starting with A mean the FDA rates the drug therapeutically equivalent to its reference drug (Orange Book).
Generics Valtrex with the same TE code
Manufacturers 15 labelers list this drug on DailyMed
Packages (NDC)
Package
500 mg – 30 in 1 bottle NDC 16714-698-01
500 mg – 90 in 1 bottle NDC 16714-698-03
500 mg – 100 in 1 bottle NDC 16714-698-02
1 g – 30 in 1 bottle NDC 16714-697-01
1 g – 90 in 1 bottle NDC 16714-697-03
1 g – 100 in 1 bottle NDC 16714-697-02
1 g – 500 in 1 bottle NDC 16714-697-04

Source: FDA drug labeling via NLM DailyMed, data as of October 31, 2026. FDA data (DailyMed, Orange Book, Drug Shortages, enforcement reports). Not a substitute for the advice of a doctor or pharmacist.