Cold Sore Medication: What Works and When to Use It
Cold sores (herpes labialis) are common and annoying. The right medicine can cut a flare short or stop it before it starts. This page gives straight answers: which drugs actually work, when to take them, basic dosing ideas, and simple prevention tips you can use today.
How medications work and when to start
Antiviral drugs don’t cure the virus, but they stop it from copying itself. That limits how big a sore gets and speeds recovery. Topical options like ointments (docosanol/Abreva or topical acyclovir) help when you catch the very start, but they’re less powerful than pills.
Oral antivirals—acyclovir, valacyclovir (Valtrex), and famciclovir—work best. Take them as soon as you feel the prodrome: tingling, burning, or itching before a visible sore. Starting at that stage gives the biggest benefit. If you wait for a full blister, pills still help, but the effect is smaller.
For recurring outbreaks, daily suppressive therapy can be a game-changer. Doctors prescribe a low daily dose of valacyclovir or acyclovir to reduce how often sores appear and how contagious you are.
Practical tips: dosing, safety, and prevention
Common short-course guidance (talk to your doctor for exact dosing): valacyclovir often comes as 2 grams taken at the first sign, then another 2 grams 12 hours later for a typical episodic course. Acyclovir and famciclovir have different schedules. Don’t self-prescribe—get a quick consult if you’re unsure.
Use topical pain relief to make symptoms bearable: over-the-counter creams with lidocaine, cold compresses, or simple analgesics (ibuprofen or acetaminophen) help. Clean hands before and after touching a sore to avoid spreading the virus to other people or parts of your body.
If you get cold sores often—more than six times a year—or they’re severe, ask your doctor about daily suppressive therapy. People with weakened immune systems need faster evaluation and more aggressive treatment.
Pregnancy and breastfeeding: some antivirals are used during pregnancy in specific situations, but you must talk to your healthcare provider. Don’t assume a medicine is safe without checking.
Small reminders that matter: avoid kissing and oral sex while you have an active sore, don’t share utensils or lip products, and protect lips from sun and cold—UV and cold weather are common triggers. A lip balm with SPF and good hydration reduce flare risk.
If a sore won’t heal in two weeks, spreads, causes fever, or makes you feel very ill, see a doctor right away. Same if you notice frequent recurrences or if you’re immunocompromised. Quick action keeps complications rare and recovery faster.
Want help finding prescription options or learning when suppression makes sense? Check with a primary care provider or dermatologist—they’ll match the right drug and schedule to your needs.
