How to Treat Fever Blisters | Speed Healing With Antivirals

You know that telltale burn or tingle on your lip — a fever blister is forming. Whether you call it a cold sore or a fever blister, treating it quickly gives you the best shot at a shorter, milder outbreak.

Do Fever Blisters Need Treatment?

Cold sores usually clear on their own in 2 to 4 weeks without treatment, notes the Mayo Clinic. But antiviral medicine can speed healing, which is why most people seek treatment at the first sign of an outbreak.

There is no cure for the herpes simplex virus that causes fever blisters, as MedlinePlus explains. Antiviral medicines do two practical things: they help current sores heal faster, and they help prevent frequent outbreaks.

Prescription Antiviral Options That Work

Prescription antiviral pills work better than creams for shortening an outbreak. The CDC lists several oral regimens depending on whether you’re treating a first outbreak or a recurrence:

• Acyclovir: 400 mg three times daily for 7–10 days for first outbreaks; recurrent episodes can be treated with 800 mg twice daily for 5 days or 800 mg three times daily for 2 days.
• Famciclovir: 250 mg three times daily for 7–10 days for first outbreaks; recurrent episodes may use 1 g twice daily for 1 day or other shortened regimens.
• Valacyclovir: 1 g twice daily for 7–10 days for first outbreaks; recurrent episodes often use 500 mg twice daily for 3 days.

Timing matters more than which drug you choose. Start treatment during the prodrome — that tingling or burning phase before the blister appears — or within about 2 days of the lesion forming. Waiting until the blister is fully formed reduces the benefit significantly.

At-Home Relief and Care

While antivirals attack the virus, supportive care keeps you comfortable. A cold, damp compress soothes the area, while a warm cloth can help with pain. Over-the-counter pain relievers work well for the soreness.

For pain and healing at the drugstore:

• Docosanol cream (brand name Abreva) may shorten healing time. Apply it at the first sign of symptoms, following package directions.
• Lidocaine or benzocaine creams numb the area and help with pain.
• Zinc oxide cream or lip balm with sunscreen protects the sore and helps prevent sun-triggered recurrences.

Apply ointments with a cotton-tipped swab rather than your finger to avoid spreading the virus. and never pick at the sore or peel burst blister skin — that invites infection and slows healing.

If you’re ready to pick up a treatment, browse our top cream picks for fever blisters to see which options reviewers rate highest.

When To See a Doctor

Most fever blisters resolve without medical attention, but certain situations warrant a call to your clinician. Seek care promptly if you have a weak immune system, your symptoms are severe, or a sore hasn’t healed within two weeks. Sores that return frequently also justify a doctor visit, since suppressive therapy may reduce outbreaks.

Eye involvement is the most urgent red flag. If you experience gritty, painful, or irritated eyes during an outbreak, seek care immediately — ocular herpes can threaten vision.