There’s nothing fun about cold sores. They can make you feel self-conscious – in addition to causing you physical pain. To make matters worse, cold sores can be very contagious. 1 As if dealing with a cold sore outbreak isn’t bad enough, imagine how you would feel knowing you passed your cold sore along to someone close to you.

When Are Cold Sores Contagious?

Cold sores are most contagious when they’re in the blistering stage and fluid is present. 1  However, it’s important to keep in mind that you can infect another person during any <a href="http://sitavig best weightloss” target=”_blank”>stage of a cold sore breakout. 1 Furthermore, even when a cold sore is not even present, virus can be transmitted to another person through “asymptomatic viral shedding”.

From the first sign of a developing cold sore to the moment your cold sore has healed and disappeared from your face, any of the following activities may transmit the virus that causes cold sores – known as herpes simplex virus, or HSV12 – to another person:

  • Kissing
  • Sharing silverware
  • Sharing food or drinks
  • Not washing your hands after touching the cold sore.

Avoiding these activities, as well as washing your hands frequently during a cold sore outbreak, is the best way to minimize the chance of passing your cold sore to another person.

Can Cold Sores Be Prevented?

Although there’s no known cure for cold sores, it is sometimes possible to prevent a cold sore from forming.

If you’re a frequent cold sore sufferer, talk to your physician about prescription Sitavig® (acyclovir), 50mg Muco-Adhesive Buccal Tablet.

Sitavig® is an FDA-approved, single-dose prescription cold sore treatment that can ease cold sore symptoms, speed up healing, and in some cases, stop cold sores before they start.

1 – Orenstein, B. W., (July 8, 2013). How Contagious Are Cold Sores? [Everyday Health – Skin & Beauty web post]. Retrieved August 15, 2015, from

2 – WedMD (May 15, 2014). Cold Sores – Causes [Skin Problems & Treatments Health Center web post]. Retrieved August 15, 2015, from


Sitavig should not be used in patients with known hypersensitivity to acyclovir, milk protein concentrate, or other components of the product.

Sitavig has not been studied in pregnant women or in immunocompromised patients and no interaction studies have been performed. Sitavig’s safety and efficacy have not been established in pediatric patients.

Sitavig is a Pregnancy Category B product; therefore it should be used during pregnancy only if the potential benefit outweighs the potential risk to the fetus. It is not known if Sitavig is excreted in breast milk; however, systemic absorption is minimal.

In a controlled clinical trial Sitavig’s most common side effects (greater than or equal to 1%) were: headache (3%), dizziness (1%), lethargy (1%), gingival pain (1%), aphthous stomatitis (1%), application site pain (1%), application site irritation (1%), erythema (1%) and rash (1%). In the same trial these side effects ranged from 0%-3% for placebo.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

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