Herpes is treatable, but current medicines do not cure it. Acyclovir, valacyclovir, and famciclovir are established antiviral medicines that can reduce the duration or severity of symptomatic episodes. Taken every day as suppressive therapy, they can also reduce how often genital-herpes recurrences happen. They do not eradicate latent HSV from the body. 123
Treatment is usually discussed in three patterns: a course for a first clinical episode, episodic treatment for a recurrence, or daily suppressive treatment. These patterns have different purposes. A schedule for a genital first episode is not automatically the schedule for a cold sore, a recurrence, suppression, pregnancy, significant immune suppression, or reduced kidney function. 123459
This guide explains the evidence without choosing a medicine, dose, duration, start or stop point, pregnancy plan, renal adjustment, interaction plan, or monitoring schedule for an individual.
The three treatment patterns
| Pattern | What it is trying to change | What it does not establish |
|---|---|---|
| First-clinical-episode treatment | A clinician-directed antiviral course for a first clinical episode of genital herpes. Current CDC guidance recommends antiviral therapy for all first clinical episodes. 1 | It does not prove when HSV was acquired, remove latent HSV, or determine the schedule for a different episode or site. 134 |
| Episodic treatment | A planned, time-limited antiviral course for a recurrence. The checked guidelines say benefit is greatest when treatment begins early around symptom or warning-symptom onset. 12345 | It is not daily suppression, does not prevent every later episode, and should not be self-selected from a symptom description without an appropriate diagnosis and plan. 1234 |
| Suppressive treatment | Antiviral medicine taken every day over time to reduce recurrence frequency. 12348 | It does not guarantee no outbreaks, cure HSV, or make transmission impossible. 1368 |
What current antivirals can and cannot change
Current systemic antivirals can improve symptoms and recurrences without removing the latent infection that remains in nerve cells. CDC says they can partially control signs and symptoms during a first or recurrent genital episode and reduce recurrences during daily suppression. CDC also states that, after the medicine is discontinued, antiviral treatment does not change the underlying risk, frequency, or severity of future recurrences. 12
That gives treatment several legitimate goals:
- reduce the duration or severity of a symptomatic episode 127
- reduce how often genital-herpes recurrences occur while suppressive treatment is being used 128
- in one defined genital HSV-2 setting, reduce but not eliminate partner acquisition 156
Those are different outcomes. Fewer symptoms do not prove no viral shedding. Less shedding does not by itself prove a partner did not acquire HSV. A transmission result from a partner trial is not the same measurement as a person's recurrence count. 16
For first-episode genital herpes, a 2016 Cochrane review found low-quality evidence that oral acyclovir reduced symptom duration compared with placebo. The underlying trials were mostly old and incompletely reported, and the review did not find evidence from two included comparisons that this treatment changed time to recurrence. 7
Topical antivirals are not a substitute for established systemic genital-herpes treatment. CDC says topical antiviral therapy offers minimal clinical benefit for genital herpes and discourages it; the 2024 European guideline also does not recommend topical agents for a first genital episode. This statement concerns genital antiviral treatment, not every product used for oral cold sores or supportive symptom relief. 13
First clinical episode: a distinct treatment question
CDC recommends antiviral treatment for all first clinical episodes of genital herpes. It notes that newly acquired genital herpes can cause prolonged or severe illness and that people whose first episode is initially mild can still experience severe or prolonged symptoms during later recurrences. That is attributed US guideline reporting, not a diagnosis or a medicine choice for a reader. 1
“First clinical episode” is a treatment category, not proof that infection happened recently. When the diagnosis has not been confirmed or the timing is uncertain, diagnosis and episode classification remain testing and clinical questions. Use the Herpes Symptoms guide for recognition limits and the Herpes Testing guide for lesion and blood-test questions. 34
Because the useful treatment window, episode definition, and schedule are context-specific, a suspected first episode is a prompt clinical-assessment question. This page does not reproduce first-episode doses or durations. 134
Episodic treatment: a plan for a recurrence
Episodic treatment is meant to shorten or ease a recurrence rather than prevent recurrences continuously. Timing is part of the evidence. CDC says recurrent genital HSV-2 treatment is most effective during the prodrome, meaning warning symptoms before a lesion, or within one day after lesions begin. WHO's broader oral-and-genital HSV fact sheet uses a within-48-hours statement. The European and FDA sources use other timing language for specific episodes and indications. 12345
These statements should not be merged into one universal deadline. They concern different episode types, sites, products, source purposes, and jurisdictions. The practical reason to discuss episodic therapy before the next recurrence is so the diagnosis, medicine, instructions, and timing are already clear. That is a planning question for clinical care, not permission to start an unreviewed medicine for any tingling, sore, or rash. 12345
Questions for an episodic-treatment conversation include:
- Is the diagnosis and HSV type established?
- Is this plan for oral or genital HSV?
- Which early symptom or lesion should count as the start of a recurrence?
- What should happen if the episode is unusual, severe, or not improving?
- Do kidney function, pregnancy, immune status, or other medicines change the plan?
Suppressive treatment: daily reduction, not eradication
Suppressive therapy means taking antiviral medicine every day over time. CDC reports that it reduces genital-herpes recurrence frequency by 70%–80% among patients with frequent recurrences. That number describes a group-level reduction during treatment, not a promise that one person will have no outbreaks. The 2024 European guideline says occasional symptomatic recurrences can still occur during suppression. 13
A 2014 Cochrane review also found that suppressive acyclovir, valacyclovir, and famciclovir reduced the proportion of immunocompetent, nonpregnant participants with at least one recurrence compared with placebo. The participants had at least four recurrences per year, averaged 11 per year before the trials, and were treated for two to 12 months. The review rated the evidence low quality and did not establish one of the three medicines as superior for preventing recurrence. 8
Treatment strategy can change over time. Current European and UK guidance describes a shared decision that can account for recurrence frequency, symptom burden, relationship context, cost, inconvenience, and changing circumstances. This guide does not tell a reader to begin, continue, pause, or stop suppression. 34
Recurrence reduction is not the same as transmission reduction
The direct transmission evidence is narrower than the recurrence evidence. The pivotal trial followed 1,484 immunocompetent, heterosexual, monogamous HSV-2-discordant couples for eight months. The source partner had clinically symptomatic genital HSV-2 and took daily valacyclovir or placebo. Both partners received safer-sex counseling and were offered condoms. 6
The trial reported two partner-acquisition outcomes separately:
- Symptomatic genital HSV-2 developed in 4 of 743 susceptible partners in the valacyclovir group and 16 of 741 in the placebo group. 6
- Any laboratory-documented HSV-2 acquisition occurred in 14 of 743 susceptible partners, or 1.9%, in the valacyclovir group and 27 of 741, or 3.6%, in placebo. 6
Transmission still occurred in the treatment group, so the finding was a reduction, not elimination. These eight-month results are not a personal annual percentage. They do not establish the same effect for genital HSV-1, people with asymptomatic HSV-2 identified only by a blood test, people with HIV, pregnancy, same-gender couples, non-monogamous relationships, multiple partners, every sexual practice, or a different medicine or schedule. Current US valacyclovir labeling also preserves population and duration limits for its transmission indication. 156
For the fuller partner evidence, condoms and barriers, symptom-free shedding, and the limits of transmission percentages, read Genital herpes transmission.
Why HSV type and infection site matter
Genital HSV-1 generally recurs less often than genital HSV-2. CDC uses that difference in its counseling about suppressive therapy and says the efficacy of suppression for preventing genital HSV-1 transmission has not been studied. It also says transmission-prevention efficacy has not been studied for a source partner with asymptomatic HSV-2 identified by serology. 1
That means the HSV-2 partner trial cannot be reused as a genital HSV-1 estimate or as an answer for asymptomatic blood-test findings. “Not studied in current guidance” is a bounded evidence gap, not proof of benefit or no benefit. 16
Oral and genital HSV may involve the same antiviral names, but the treatment evidence is not interchangeable. The current US valacyclovir label separates cold sores, initial genital episodes, recurrent genital episodes, daily suppression, and reduction of transmission, with different indication, timing, age, population, and duration boundaries. It is one US product label, not a universal prescribing table. 25
Use HSV-1 vs HSV-2 for the fuller type-and-site comparison.
Why there is no universal “best” medicine or schedule here
CDC says acyclovir, famciclovir, and valacyclovir appear equally effective for episodic genital-herpes treatment. The Cochrane suppressive-treatment review did not establish that one was superior for preventing recurrence in its selected trial population. Neither finding means the medicines are interchangeable for every person. 18
A responsible selection has to preserve more than a drug name:
- oral or genital site and HSV type
- first clinical episode, recurrence, suppression, or transmission goal
- symptom timing and whether the diagnosis is established
- formulation and route
- age, pregnancy or breastfeeding, kidney function, and immune status
- other medicines and product-specific warnings
- jurisdiction, availability, label, and guideline scope 13459
An exact regimen table would compress those variables into something that looks individualized while leaving out the clinical selection that makes a schedule meaningful. The checked sources contain usable schedules for clinicians; this guide gives readers the questions needed to discuss them.
Safety and special-context boundaries
CDC says long-term safety and efficacy have been documented for daily acyclovir, valacyclovir, and famciclovir in its guideline populations. That population statement is not an individual safety verdict. The current US valacyclovir label separately defines contraindications, warnings, population and duration limits, and renal adjustments. 15
Kidney function can require dose adjustment: CDC states this for acyclovir, and the current US valacyclovir label provides renal-adjustment instructions for that product. This guide cannot calculate an adjustment or decide what monitoring is needed. The applicable product label and clinical review must account for its age and population limits, contraindications, warnings, pregnancy information, kidney function, immune status, and other medicines. 15
Pregnancy has its own antiviral, timing, delivery, and newborn-risk guidance. Tell the prenatal team about genital HSV, new genital symptoms, or a possible new exposure rather than applying a general adult schedule. This page does not declare a particular antiviral safe in pregnancy or provide an obstetric treatment plan. 134
People with HIV or other significant immune suppression have population-specific evidence and may have atypical, severe, prolonged, or resistant disease. NIH's treatment guidance for adults and adolescents with HIV is not generalized here. 1349
Severe, disseminated, eye, central-nervous-system, and newborn HSV use different specialist or hospital pathways. The Symptoms guide gives bounded prompt and urgent-care routing; this page does not reproduce those management protocols. 19
What if lesions persist or recur during treatment?
Do not assume that persistent lesions prove resistance, and do not increase, combine, or switch medicines from a general guide. CDC says lesions that persist or recur while antiviral treatment is being taken should raise possible acyclovir resistance and prompt viral culture for sensitivity testing and infectious-disease consultation. NIH likewise treats resistant HSV as specialist-managed in its HIV guidance. 19
Questions to take into clinical care
- Is the diagnosis confirmed, and do I know the HSV type and infection site?
- Is the goal to treat a first clinical episode, shorten a recurrence, reduce recurrence frequency, or address a transmission concern?
- If an episodic plan is appropriate, which symptoms should trigger it and what timing instructions apply to this specific prescription?
- If daily suppression is being considered, which outcome matters and how will the plan be revisited?
- Does the transmission evidence apply to my HSV type, symptom history, and relationship context, or is that evidence missing?
- Do kidney function, pregnancy or breastfeeding, immune status, age, other medicines, or a past reaction change the options?
- Which formulation and local guideline or product label applies?
- What should I do if lesions are unusual, severe, persistent, or recurring during treatment?
What this page does not cover
This guide does not evaluate supplements, home remedies, or products marketed as natural cures. It also does not turn an experimental program into an available treatment recommendation. HSVHQ tracks experimental vaccines, antivirals, gene editing, and other programs separately in the HSV research tracker; tracker inclusion does not mean a program is available or appropriate for an individual.
Current established antivirals remain symptom and recurrence management tools. Separately, daily valacyclovir has a bounded US transmission indication and a genital HSV-2 trial result in the population described above. Neither finding is evidence of latent-virus eradication or cure. 1256
Evidence and sources
Evidence last checked: 6 September 2026
Evidence scope: The current US CDC STI guideline; 2024 European and BASHH genital-herpes guidelines; the 2025 WHO HSV fact sheet; November 2025 US valacyclovir labeling; the pivotal 2004 transmission trial; Cochrane reviews of first-episode and suppressive treatment; and 2025 NIH guidance for adults and adolescents with HIV.
Important limitations: CDC's operative US STI guideline remains the 2021 edition. Much of the antiviral trial base is older, and the systematic reviews identify low-quality evidence and reporting limitations. Direct transmission evidence is narrow. Oral-herpes treatment is covered only enough to prevent genital-regimen extrapolation. Pregnancy, newborn, ocular, neurologic, disseminated, resistant, and immunocompromised treatment protocols are outside scope.
Sources
- CDC. Sexually Transmitted Infections Treatment Guidelines, 2021 (opens in a new tab)Return to citation
- World Health Organization. Herpes simplex virus (opens in a new tab)Return to citation
- Patel R, et al. 2024 European guidelines for the management of genital herpes (opens in a new tab)
DOI: 10.1111/jdv.20450
Return to citation - Patel R, et al. BASHH UK national guideline for the management of anogenital herpes, 2024 (opens in a new tab)
DOI: 10.1177/09564624241282396
Return to citation - DailyMed. FDA-approved Valtrex prescribing information, November 2025 (opens in a new tab)Return to citation
- Corey L, et al. Once-daily valacyclovir to reduce the risk of transmission of genital herpes (opens in a new tab)
DOI: 10.1056/NEJMoa035144
Return to citation - Cochrane. Interventions for men and women with their first episode of genital herpes (opens in a new tab)
DOI: 10.1002/14651858.CD010684.pub2
Return to citation - Cochrane. Oral antiviral treatment to prevent genital herpes outbreaks in immunocompetent and nonpregnant patients (opens in a new tab)
DOI: 10.1002/14651858.CD009036.pub2
Return to citation - National Institutes of Health. Herpes Simplex Virus: Adult and Adolescent Opportunistic Infections (opens in a new tab)Return to citation