Valtrex
An oral medication used to treat shingles, cold sores, and genital herpes.
Where Valacyclovir is approved
All regulators →Of the three regulators tracked here, the first to approve Valacyclovir was the US, on 23 Jun 1995. It is approved in 2 of the 3 regulators tracked here.
From the regulators' own registers: FDA Drugs@FDA, the EMA medicines list and Health Canada's Notice of Compliance database. Dates are the first listed approval of a product containing only this substance; combination products and nationally authorised EU medicines are not counted.
What health systems spend on Valacyclovir
All medicines →From NHSBSA Prescription Cost Analysis (Open Government Licence v3.0) and CMS State Drug Utilization Data. Both are gross amounts: neither system publishes its discounts or rebates per drug. Products combining several substances are not counted here.
How Valacyclovir works
All drug targets →- Human herpesvirus 1 DNA polymerase inhibitor InhibitorChEMBL only
- HIV infectious diseasePhase 3
- Herpes simplex encephalitisPhase 3
- PeriodontitisPhase 3
- Prostate cancerPhase 3
- Alzheimer diseasePhase 2
- COVID-19Phase 2
- Cognitive impairmentPhase 2
- Anaplastic astrocytomaPhase 2
- Bipolar disorderPhase 2
- Breast cancerPhase 2
Mechanisms and diseases from ChEMBL via the Open Targets Platform (release 26.09), ChEMBL record CHEMBL1349, CC BY-SA 3.0. Targets checked against the IUPHAR/BPS Guide to PHARMACOLOGY (2026.3), ligand 4824, CC BY-SA 4.0. Trial phases are not approvals: approved uses are shown from the regulators' own records where we hold them.
Patient leaflets for Valacyclovir
The package leaflet is the official guide for patients that comes with every medicine. These links go to the regulators that publish it.
- UKUnited Kingdom: Search MHRA ProductsPatient information leaflets and SmPCs for UK-licensed products.
- USUnited States: Search DailyMedFDA-approved labels, including patient and medication guides.
Leaflets differ between brands and countries; always read the one that comes with your own medicine. This is regulatory information, not medical advice.
Reference identifiers for Valacyclovir
- ATC code
- J05AB11
- ChEMBL
- CHEMBL1349
- DrugBank
- DB00577
- PubChem CID
- 135398742
- CAS number
- 124832-26-4
- FDA UNII
- MZ1IW7Q79D
- Wikidata
- Q418594
- Wikipedia
- Valaciclovir
Codes that identify this medicine in other databases, from Wikidata (CC0), matched by its ChEMBL ID. The ATC code is the WHO classification of what the medicine is used for.
What Valtrex is used for
VALTREX is a deoxynucleoside analogue DNA polymerase inhibitor indicated for: Adult Patients ( 1.1 ) • Cold Sores (Herpes Labialis) • Genital Herpes • Treatment in immunocompetent patients (initial or recurrent episode) • Suppression in immunocompetent or HIV-1−infected patients • Reduction of transmission • Herpes Zoster Pediatric Patients ( 1.2 ) • Cold Sores (Herpes Labialis) • Chickenpox Limitations of Use ( 1.3 ) The efficacy and safety of VALTREX have not been established in immunocompromised patients other than for the suppression of genital herpes in HIV-1−infected patients. 1.1 Adult Patients Cold Sores (Herpes Labialis) VALTREX is indicated for treatment of cold sores (herpes labialis). The efficacy of VALTREX initiated after the development of clinical signs of a cold sore (e.g., papule, vesicle, or ulcer) has not been established. Genital Herpes Initial Episode: VALTREX is i…
How it works
12.1 Mechanism of Action Valacyclovir is an antiviral drug active against α-herpes viruses [see Microbiology ( 12.4 )].
Explore more
How this page is built
The facts on this page are pulled directly from official U.S. FDA datasets — they are not written from memory. Each field below names the dataset it came from, so you can check it yourself.
- FDA Drug Label (openFDA) ↗ Indications, mechanism of action and pharmacologic class
- Drugs@FDA ↗ First FDA approval date and the company holding the application
- FDA Drug Shortage Database ↗ Current US supply / shortage status
Plain-English summaries and drug-class explainers are written and reviewed by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 10 Oct 2026. How every register is built: methodology · fixes we have made: corrections log.