Valacyclovir (Valtrex and others)

How Medicare covers it

Part D (tablets taken at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Treats herpes virus infections in adults: cold sores (herpes labialis); genital herpes — first episodes, recurrent episodes, long-term suppression in immunocompetent and HIV-infected patients, and reducing the risk of passing it to a partner; and herpes zoster (shingles). In children it is used for cold sores and chickenpox. It does not cure herpes.

What it is for, in depth

Valacyclovir is an antiviral medicine used to treat herpes virus infections. In adults, it treats cold sores, also called herpes labialis, and genital herpes. For genital herpes, it is used for a first episode, for repeat episodes, and for long-term suppression to reduce future outbreaks, including in immunocompetent patients and in HIV-infected patients. It is also used to reduce the risk of passing genital herpes to a partner. In adults, it also treats herpes zoster, known as shingles. In children, it is used for cold sores and for chickenpox. Valacyclovir does not cure herpes. It comes as oral tablets, in 500 MG and 1000 MG strengths, taken by mouth with or without food, with the dose and length of treatment depending on the condition being treated.

How it works

Valacyclovir is converted in the body to acyclovir, a nucleoside analogue that blocks the herpes virus DNA polymerase enzyme. Without working DNA polymerase, the virus cannot copy its DNA and multiply.

How it is taken

Tablets by mouth, with or without regard to meals. Doses depend on the condition: cold sores — 2 grams every 12 hours for 1 day, started at the first tingle, itch, or burning; genital herpes first episode — 1 gram twice a day for 10 days; recurrences — 500 mg twice a day for 3 days; suppression — 1 gram once a day; shingles — 1 gram three times a day for 7 days. Drink plenty of fluids while taking it, and doses are reduced when the kidneys do not work well.

Common side effects

The most common side effects in adults (more than 10% and more often than with placebo in at least one use) are headache, nausea, and abdominal pain. Headache was also the most common effect in children.

Serious warnings

Serious reactions described in the label include thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), reported in patients with advanced HIV and transplant patients at high doses; acute kidney failure; central nervous system effects such as agitation, confusion, hallucinations, and seizures; and severe skin reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, and anaphylaxis. Stop the drug and seek care for a painful rash with mouth sores.

Who should be careful

Do not take it if you have had a serious allergic reaction to valacyclovir, acyclovir, or any component of the tablets. Older adults and people with kidney problems need dose adjustment and good hydration. Its safety in immunocompromised patients is established only for suppression of genital herpes in HIV-infected patients.

Major interactions

The label states that no clinically significant drug-drug or drug-food interactions with valacyclovir are known.

Why it is in its tier

Valacyclovir is most often placed on Tier 3. It is listed by 100.0% of Part D plans, and 53.9% of listing plans place it on Tier 3, which makes Tier 3 the most common tier. Tier 3 is a preferred brand or higher-cost tier, so cost share is generally higher than on Tier 1 or Tier 2. Because 53.9% is only a plurality, placement is split across tiers, and many plans use a lower tier instead. Valacyclovir is a generic medicine, sold as Valacyclovir HCl, rather than only as a brand product. In the CMS dashboard, average spending per beneficiary in 2024 was $69.60, which is CMS program average spending, not a copay or what a patient pays at the pharmacy. Individual plans vary, and readers should check their own plan's formulary.

Sources

• VALACYCLOVIR HYDROCHLORIDE TABLET, FILM COATED [AMERICAN HEALTH PACKAGING] — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus — Valacyclovir

What official patient guides say

Valacyclovir comes as a tablet to take by mouth, with or without food, and it is taken 1 to 3 times a day depending on the condition being treated — for cold sores, 2 doses twelve hours apart; for shingles and chickenpox, every 8 hours for 7 days; to treat genital herpes, twice a day for as long as your doctor tells you; and to prevent outbreaks, once or twice daily. Take it exactly as directed, use it as soon as possible after symptoms appear, and continue taking it even if you feel well without stopping unless you talk to your doctor first; unless your doctor tells you otherwise, continue your normal diet. If you miss a dose, take it as soon as you remember it, but if it is almost time for the next dose, skip the missed dose and continue your regular schedule — do not take a double dose to make up for a missed one. Keep the medication in the container it came in, tightly closed and out of reach of children, and store it at room temperature away from excess heat and moisture, not in the bathroom.

Source: MedlinePlus — Valacyclovir

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is 0.42379 per unit (VALACYCLOVIR HCL 1 GRAM TABLET) — about nan for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-08

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 5,495 list Valacyclovir (Valtrex and others) — 100% of plans. Most of those plans put it on Tier 3: 2,962 plans, 53.9% of the plans that list it. Other plans place it on Tier 2 (2,042 plans), Tier 1 (459 plans) or Tier 4 (32 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 2; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 2; Aetna Medicare Value Plus (PPO) puts it on Tier 2. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.