Ask Your Pharmacist

December 20, 2018

How do I stop a cold sore fast? I can feel it starting.


It’s estimated that up to 50 per cent of people are affected by cold sores. One in three adolescent children is believed to have the virus that causes cold sores, making this a lot more common than even I realized. There are treatments available by prescription and over-the-counter options. When it comes to treating cold sores, the quicker the better.

Cold sores are caused by a viral infection (Herpes Simplex Virus or HSV for short) that causes painful itchy sores on the oral mucosa or lip. Infection is caused by skin-on-skin contact with someone who has a cold sore or by sharing a cup or make-up for example. Most of the time the virus is dormant, and the frequency that sores appear depends on the individual. Some people get several cold sores per month while others can go years without a breakout. At this point, you may be thinking: “What if I have cold sores and don’t know because I haven’t had a breakout in years”.  It’s possible, but typically the first time the Herpes Simplex Virus causes infection, it is much more severe and may involve having flu-like symptoms such as malaise, fever, chills, muscle aches, lymphadenopathy (swollen lymph nodes), and multiple painful blisters.

Identifying the signs of a cold sore early is important to reduce the severity and duration of symptoms. Luckily most people experience early symptoms of itching and burning two to 24 hours before a blister forms, which should act as a sign to say it’s time to seek treatment. If not treated, cold sores usually last about seven to 10 days. Treatment with prescription oral antiviral tablets (Famvir® in particular) has been shown to reduce the duration on average by two or two and a half days. Famvir® can be taken as a single dosage making it a convenient option at the onset of symptoms. There is also an antiviral cream available which reduces duration by a day on average. Abreva® is available over-the-counter without a prescription and can reduce blister duration by around 17 hours. Try to avoid using rubbing alcohol, peroxide and witch hazel as these can dry out the skin and make it worse. I recommend using an unscented, non-medicated, lip balm like Vaseline to keep the lips and skin hydrated.

By reducing stress, eating well, and getting a good night sleep, you can help reduce the recurrence of cold sore outbreaks. Using a lip balm or sunscreen that contains SPF 30 when out in the sun can help prevent breakouts, even in the winter. In addition to these strategies, I recommend having a treatment available to use at the first the sign of a breakout to reduce discomfort, blister duration, and reduce the time cold sores can be spread. In New Brunswick, pharmacists are trained to assess and treat cold sores and when appropriate, they can write prescriptions to treat them. The importance of treating cold sores quickly, and the effectiveness of prescription antivirals make your pharmacist a valuable and accessible option to help reduce your cold sore duration.

Jared Mactavish (BSc., Pharm) is a pharmacist in Saint John. His opinions expressed in this newspaper are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment. Send your questions to