Used for: Herpes zoster (Shingles), Herpes simplex virus infections
Chinese name:

What is Valtrex?

Valtrex is a brand medication that contains Valaciclovir, which belongs to a class of antivirals known as guanine nucleoside analogue. It works by inhibiting the DNA synthesis in viruses to destroy them. It is therefore used to treat herpes simplex virus infection and herpes zoster, commonly known as shingles. 

How to use it?

Valtrex is available as tablets. It can be taken with or without food. If you experience stomach discomfort, taking it with food can reduce the side effects.

For Herpes zoster infection,
Take 1g 3 times daily for 7 days.
Immunocompromised adult
Take 1g 3 times daily for 7 days or more, continue for 2 days after crusting of lesions. 


For Herpes simplex virus, the first episode
Take 500mg twice daily for 5 days. Continue if healing incomplete or new lesions form.
Immunocompromised adult
Take 1g twice daily for 10 days.

Herpes simplex virus, recurrence
Take 500mg twice daily for 3-5 days.
Immunocompromised adult
Take 1g twice daily for 5-10 days.

What are the side effects of Valtrex?

Common side effects of Valtrex include diarrhea, headache, nausea, vomiting and dizziness.

Who should not take Valtrex?

  • Pregnant and breastfeeding women
  • Patients who are allergic to Valtrex and any components in the formulation
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Where to buy Valtrex in Hong Kong?

In Hong Kong, Valtrex is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Valtrex in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Available dosage
  • 500mg (Tablets)
Drug class
Sub class
Guanine Nucleoside Analogues
Generic Names
Other drugs in same class
Used for: Herpes simplex keratitis, Cytomegaloviral infections
Chinese name:
Used for: Herpes simplex virus infections, Herpes zoster (Shingles)
Chinese name:
Used for: Herpes zoster (Shingles), Herpes simplex virus infections
Chinese name:
Used for: Cytomegaloviral infections, Cytomegaloviral retinitis
Chinese name: