Valacyclovir

Valacyclovir has been studied in 4 papers since 2025: 3 observational studies in people, 1 review; 3 in the past year. The newest story, Nov 9, 2026: “Herpes drugs linked to fewer starts of Alzheimer’s treatment”.

Intervention

4 papers study it3 findingsUpdated Jun 15, 2026

PubChem ChEBI MeSH

See all 4 papers on valacyclovir

At a glance

The findings reach people, from one lab or study. 2 independent labs in 2 countries; 12 trials, none about aging, 1 with no results posted.

“All three AHDs were associated with a lower likelihood of future AD drug prescription: valacyclovir HR 0.10, acyclovir HR 0.09, famciclovir HR 0.07.”

Association between the use of anti-herpetic drugs and subsequent initiation of Alzheimer's disease drug treatment: Dutch population-based inception cohort studyBMJ open2026doi:10.1136/bmjopen-2025-114033

None of its findings points the other way.

C, W, M, H: cells, worms or flies, mice, humans. Dark: independent labs found the same change there. Light: one lab or one study. Outline: nothing yet.

Labs are independent when their papers share no last author and no institution.

About aging: the drug’s trials about aging. The total counts its trials for every use.

No results posted: trials that ended over a year ago with no results on ClinicalTrials.gov and no paper reporting them.

Company ties: findings with an author at a company, or from a paper whose competing-interests statement declares ties to one.

2 independent labs in 2 countries
12 trials, none about aging, 1 with no results posted

Funders: Akershus University Hospital and others
2 of 3 findings with company ties

Humans3

What did studies of valacyclovir find?

Studies of valacyclovir measured one outcome, transposable element activity.

Transposable element activity

downin human cells1

1 study

Valacyclovir inhibits transposable element activity in virus-infected human brain organoid model.
“This LINE1 dysregulation can be partially reversed by the usage of anti-HHV drugs (valacyclovir and acyclovir) in a virus-infected human brain organoid model.”
Cellsin virus-infected human brain organoid model
Human herpesvirus-associated transposable element activation in human aging brains with Alzheimer's disease
Alzheimer's & dementia : the journal of the Alzheimer's AssociationFeb 1, 2025

What is valacyclovir linked with?

Studies link valacyclovir with 2 measures: alzheimer's disease drug treatment initiation and Alzheimer's disease.

Alzheimer's disease drug treatment initiation

downin humans1HR 0.1

1 study

Valacyclovir is linked with a lower risk of alzheimer's disease drug treatment initiation in humans (Dutch population-based cohort) (valacyclovir HR 0.10, acyclovir HR 0.09, famciclovir HR 0.07).
“All three AHDs were associated with a lower likelihood of future AD drug prescription: valacyclovir HR 0.10, acyclovir HR 0.09, famciclovir HR 0.07.”
HumansDutch population-based cohortn = 262,757
Herpes drugs linked to fewer starts of Alzheimer’s treatment
BMJ openJun 15, 2026

Alzheimer's disease

downin humans1

1 study

Valacyclovir is linked with a lower risk of Alzheimer's disease in real-world patient database.
“usage of valacyclovir and acyclovir was significantly associated with reduced incidence of AD in a large real-world patient database.”
Humansin real-world patient database
Human herpesvirus-associated transposable element activation in human aging brains with Alzheimer's disease
Alzheimer's & dementia : the journal of the Alzheimer's AssociationFeb 1, 2025

Who is developing valacyclovir?

1 company: Gilead Sciences.

Companies: Gilead SciencesPhase 2HSV-2 infection

Trial sponsors

Candel Therapeutics
Company6 trialsPhase 31,581 people
Gilead Sciences
Company1 trialPhase 2300 people
AiCuris Anti-infective Cures
Company1 trialPhase 291 people
Vanderbilt University Medical Center
1 trialPhase 440 people
Icahn School of Medicine at Mount Sinai
1 trialPhase 2150 people
The Methodist Hospital Research Institute
1 trialPhase 1/24 people

Latest

3 papers in 12 months

BMJ OpenJun 16

Herpes drugs linked to fewer starts of Alzheimer’s treatment

Antiviral use was linked to a 90% lower rate of starting Alzheimer’s medication at any given time compared with nonuse.Antiviral use was linked to a 90% lower rate of starting Alzheimer’s medication at any given time compared with nonuse.

Cohort · 262,757 peopleAlzheimer's disease