What is a cold sore (herpes labialis)?
Cold sores — also called fever blisters or oral herpes — are small, painful blisters on or around the lips caused by the herpes simplex virus, most often HSV-1. After a first infection the virus stays dormant and can reactivate, so many people get recurrent outbreaks in the same spot. An outbreak usually starts with a tingling, itching, or burning "prodrome," then small fluid-filled blisters form, break, and crust over before healing — typically within 7 to 10 days. Cold sores are very common and are not a sign of poor hygiene. Antiviral medicine works best when started at the very first sign of tingling.
How online cold sore prescriptions work
You complete a secure online assessment describing your symptoms, how long ago they started, your history of cold sores, any prior antiviral use, allergies, medications, kidney health, and pharmacy preference. A licensed physician reviews the information and may follow up if more detail is needed. If your symptoms fit a typical cold sore and there are no safety concerns, the clinician can send an electronic prescription to your selected pharmacy for same-day pickup in most cases.
Vyta.co does not automatically prescribe antivirals. If your answers suggest eye involvement, a spreading or systemic infection, a weakened immune system, serious kidney disease, pregnancy, or an uncertain diagnosis, the clinician may recommend in-person care instead.
Pharmacy pickup
Clinician-reviewed
No charge if not prescribed
When online cold sore treatment is appropriate
Telehealth may be appropriate for adults with a typical, recognizable cold sore — tingling followed by blisters or a sore on or around the lips — especially someone who has had cold sores before and knows the pattern.
Because cold sore symptoms can overlap with other lip and mouth conditions, your clinician reviews the full intake before deciding whether an antiviral is clinically appropriate.
When to see a doctor in person
Online care is not right for every lip or mouth symptom. Seek in-person care if any of the following apply.
- A sore, blister, pain, or redness in or near the eye, or any change in vision — this needs same-day eye care
- A rash or blisters spreading well beyond the lips or face, facial swelling, or fever
- A weakened immune system, serious kidney disease, or pregnancy or breastfeeding
First-line antivirals for cold sores
Cold sores are treated with oral antiviral medicines — valacyclovir, acyclovir, or famciclovir. Valacyclovir is often prescribed as a convenient single-day regimen: 2,000 mg taken twice in one day, 12 hours apart, started at the first sign of tingling. Acyclovir is usually taken as a short multi-day course, and famciclovir also has single-day options. These medicines shorten and ease an outbreak but are not a cure, and they work best the earlier they are started.
Antivirals are generally well tolerated. Because valacyclovir and acyclovir are cleared by the kidneys, your clinician will ask about kidney health and may adjust the choice or dose. Your clinician selects the medication and dosing based on your symptoms, allergies, kidney function, and prior treatment.
What triggers cold sores?
Once you carry the herpes simplex virus, outbreaks can be set off by common triggers — sun or UV exposure, physical or emotional stress, being run down or sick (hence "fever blisters"), and for some people, lip injury or hormonal changes. Triggers vary from person to person. Using lip balm with SPF and starting an antiviral at the first tingle can help blunt recurrent outbreaks.
What if cold sores keep coming back?
Frequent recurrences are common and treatable. Some people do well taking an antiviral at the first sign of each outbreak; those with very frequent or severe outbreaks may benefit from daily suppressive therapy, which a clinician can discuss. If your outbreaks are unusually frequent, severe, slow to heal, or ever involve the eye, an in-person evaluation is worthwhile.
