Valacyclovir vs. Valtrex

Valacyclovir is the generic form of the brand Valtrex®.

Both medications work similarly in the body.

General Info
Side Effects
Safety Information

How does Valacyclovir work?

Valacyclovir is used to treat herpes virus infections, including herpes labialis (also known as cold sores), herpes zoster (also known as shingles), and herpes simplex (also known as genital herpes).

Valacyclovir can be used as an Episodic Therapy or a Suppressive Therapy for the treatment of genital herpes:

  • Episodic Therapy: This is when you take valacyclovir for an individual outbreak as it occurs. Typically, you would start valacyclovir within 1 day of noticing a genital lesion or at the first sign of any prodromal symptoms (tingling, itching, or burning) that precede some outbreaks. This type of therapy can shorten the time to healing of the herpes lesions.
  • Suppressive Therapy: This is when you take valacyclovir on a daily basis. Suppressive therapy is often recommended for people who experience frequent or severe recurrences or those people who would like to reduce the risk of transmission to a sexual partner who does not have genital herpes.

Arrange a private and secure video call with one of our US-licensed doctors today to determine which approach is better for you.  

What are some of the more common side effects of valacyclovir?

You may experience side effects with this medication. These side effects are common and typically go away with time and regular use:

  • Headache
  • Nausea
  • Stomach Pain
  • Vomiting
  • Dizziness
  • Side effects in HIV-infected adults may also include:
  • Tiredness
  • Rash

What are the less common but concerning side effects that I should contact a healthcare provider immediately for?

  • Any sign of an allergic reaction
  • Changes in mood or in the way that you are acting
  • Feeling confused
  • Difficulty speaking
  • Feeling shaky, having difficulty moving, or feeling stiff
  • Seizures
  • Bruising or bleeding, dark urine, yellowing of the skin or eyes
  • Severe weakness or fatigue
  • Difficulty passing urine or blood in the urine
  • Hallucinations
  • Valacyclovir does not cure genital herpes. There is no cure for genital herpes.
  • Valacyclovir used on a daily basis (SUPPRESSIVE THERAPY) with safer sex practices can lower (but not completely eliminate) the chances of passing genital herpes to your partner.
  • 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.

Do not use valacyclovir for the treatment of genital herpes if you:

  • Have never had the diagnosis of genital herpes made by a healthcare provider in-person
  • Are hypersensitive to valacyclovir, acyclovir, or any component of valacyclovir’s formulation
  • Main Ingredient: Valacyclovir hydrochloride
  • Inactive ingredients: carnauba wax, colloidal silicon dioxide, crospovidone, FD&C Blue No. 2 Lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, titanium dioxide, edible white ink

If any of the following conditions apply to you, please speak with a healthcare provider in-person about seeking treatment for your genital herpes:

  • Younger than 18 years of age
  • Pregnant or breastfeeding
  • HIV infection or AIDS
  • Kidney or liver problems
  • History of a bone marrow transplant or kidney transplant
  • Weakened immune system not related to HIV infection
  • Aseptic encephalitis or transverse myelitis
  • Urinary retention issues
  • Widespread herpes simplex virus
  • History of seizure disorder

What will happen once I stop using valacyclovir for suppression of genital herpes?

Once this treatment is stopped, you may experience genital herpes outbreaks at the same frequency that you did prior to using valacyclovir for suppression. You are also likely to experience increased viral shedding, even when you don’t have an outbreak. This may increase the risk of infecting a sexual partner with the herpes virus.

Please tell your physician if you are currently taking any of the following medicines, as they may have an interaction with valacyclovir. If you are taking any of these medicines, you must see a healthcare provider in-person for treatment of your genital herpes:

  • Cladribine
  • Clozapine
  • Foscarnet
  • Mycophenolate
  • Talimogene laherparepvec
  • Tenofovir Products
  • Theophylline Derivatives
  • Tizanidine
  • Zidovudine

Please read the following information regarding the Varicella Virus Vaccine and the Zoster Vaccine:

  • Varicella Virus Vaccine: avoid use of valacyclovir within the 24 hours prior to administration of the varicella vaccine, and avoid use for 14 days after vaccination.
  • Zoster Vaccine (Live/Attenuated): discontinue valacyclovir for at least 24 hours prior to and 14 days after receiving a live attenuated zoster vaccine.

These are not all the possible side effects of Valacyclovir

Tell your doctor if you have any side effect that bothers you or doesn’t go away.