Three prescription antiviral medications treat herpes effectively: acyclovir, valacyclovir, and famciclovir. All three work by blocking the virus from copying itself, which shortens outbreaks, reduces symptoms, and lowers the chance of spreading the virus to a partner. There is no cure for herpes, but these medications make a significant difference in how often outbreaks happen and how long they last.
The Three Core Antiviral Options
Acyclovir, valacyclovir, and famciclovir are all nucleoside analogues, meaning they interfere with the virus’s ability to replicate its DNA. They work against both HSV-1 (which typically causes oral herpes or cold sores) and HSV-2 (which typically causes genital herpes). All three are taken by mouth as pills.
Valacyclovir is actually a prodrug of acyclovir, meaning your body converts it into acyclovir after you swallow it. The advantage is better absorption, which means fewer pills per day. Acyclovir works well but requires more frequent dosing. Famciclovir is a separate drug that works through the same general mechanism and is equally effective.
For most people, the choice between these three comes down to convenience and cost. Valacyclovir’s twice-daily dosing makes it the most commonly prescribed. Acyclovir is often the cheapest option but needs to be taken three times a day. Famciclovir is also taken three times daily for initial episodes. All three are available as generics.
Treating a First Outbreak
A first herpes outbreak is usually the most painful and longest lasting, so treatment for the initial episode runs longer than for recurrences. The CDC recommends a 7 to 10 day course, and treatment can be extended if sores haven’t fully healed by day 10. Starting medication as early as possible after symptoms appear gives the best results. The sooner antiviral medication gets into your system, the less time the virus has to replicate and cause damage to skin cells.
First outbreaks can include flu-like symptoms, swollen lymph nodes, and painful sores that take two to three weeks to heal without treatment. Antivirals shorten that healing time and reduce the severity of symptoms noticeably.
Episodic vs. Suppressive Therapy
After the first outbreak, you and your provider will typically choose between two approaches: episodic therapy or suppressive therapy.
Episodic therapy means keeping medication on hand and starting a short course at the first sign of an outbreak. Many people learn to recognize prodromal symptoms, the tingling, itching, or burning that shows up before sores appear. Starting medication during this window can shorten the outbreak or even prevent sores from fully developing. Episodic treatment courses are shorter than initial outbreak treatment, usually running three to five days.
Suppressive therapy means taking a low dose of antiviral medication every single day, whether or not you’re having an outbreak. This approach is typically recommended if you get six or more outbreaks per year, if outbreaks cause significant distress, or if you want to reduce the risk of transmitting herpes to a sexual partner. Daily suppressive therapy reduces viral shedding (the periods when the virus is active on the skin without visible sores), which is one of the main ways herpes spreads.
Many people stay on suppressive therapy for a year or more, then reassess with their provider. Outbreak frequency often decreases naturally over time, especially with HSV-2, so some people eventually switch to episodic therapy.
Side Effects Are Typically Mild
These antivirals are well tolerated by most people. The most common side effects of valacyclovir are headache, nausea, and abdominal pain, reported by roughly 10% of users. Acyclovir and famciclovir have similar side effect profiles. Serious reactions are rare.
People with kidney problems need adjusted doses because these drugs are cleared through the kidneys. Older adults are more likely to experience neurological side effects like confusion or dizziness, partly because kidney function naturally declines with age. If you have known kidney issues, your provider will adjust the dose accordingly.
Long-term use for suppressive therapy has been studied extensively and is considered safe. Some people take daily antivirals for years without issues.
Over-the-Counter and Topical Options
For oral herpes (cold sores), docosanol cream is available over the counter under the brand name Abreva. It can modestly shorten healing time if applied at the very first sign of a cold sore, but it’s far less effective than prescription antivirals. Topical prescription antivirals like acyclovir cream also exist for cold sores, though oral medication works better because it reaches higher concentrations in the affected tissue.
For genital herpes, topical treatments alone are not recommended. Oral antiviral pills are the standard of care.
What About L-Lysine and Natural Remedies?
L-lysine is the most commonly discussed natural supplement for herpes prevention. It’s an amino acid that some people take daily hoping to reduce outbreaks. The clinical evidence, however, is underwhelming. A controlled crossover study of 65 patients taking 1,000 mg of L-lysine daily found no significant effect on either the recurrence rate or the healing time of cold sores. A slightly higher number of patients remained outbreak-free during the lysine period compared to placebo, but the overall conclusion was that lysine had no meaningful prophylactic effect.
Other supplements like zinc, vitamin C, and various herbal extracts appear in online recommendations, but none have the kind of rigorous clinical evidence that supports prescription antivirals. If you want to try L-lysine alongside antiviral medication, it’s unlikely to cause harm, but it shouldn’t replace proven treatment.
Why Knowing Your Herpes Type Matters
It’s increasingly recognized that identifying whether you have HSV-1 or HSV-2 helps guide treatment decisions. HSV-1 genital herpes tends to recur less frequently than HSV-2, which means someone with genital HSV-1 may do fine with episodic therapy alone, while someone with genital HSV-2 might benefit more from daily suppression. If your provider hasn’t specified your type, it’s worth asking. Testing from an active lesion using a nucleic acid test or viral culture is the most reliable method.
Herpes Treatment During Pregnancy
Pregnant individuals with a history of genital herpes are recommended to start daily antiviral prophylaxis at 36 weeks of pregnancy. This reduces the risk of an active outbreak at the time of delivery, which is important because herpes can be transmitted to the newborn during birth and cause serious complications. At the onset of labor, providers will ask about any herpes symptoms, including prodromal signs like pain or burning, to determine whether a cesarean delivery is needed.
Treatments on the Horizon
For people with herpes strains that have become resistant to standard antivirals (a problem mostly seen in immunocompromised patients), a new drug called pritelivir is moving toward FDA approval. It works through an entirely different mechanism than existing medications, targeting a different part of the virus’s replication machinery. In a phase 3 trial of 101 immunocompromised patients with resistant herpes, pritelivir achieved a 62.7% lesion healing rate compared to 34.0% with existing alternatives. It also had fewer side effects, with only 2% of patients discontinuing due to drug-related adverse events compared to 20% on standard alternatives. An FDA application is expected in early 2026. For most people with herpes that responds to current antivirals, this won’t change their treatment, but it represents a meaningful advance for those with limited options.