Every couple of weeks a patient comes to our pharmacy and asks me what they should use to treat a cold sore.

Because cold sores are easily spread between people, prevention by avoiding contact with the virus is really the best way to manage cold sores. Cold sores are most contagious when they are an open lesion, which usually lasts about 3 to 5 days until the sore crusts over. I always remind people to take measures to try to avoid spreading the virus to other people. For example, I tell people not to share cups, forks, spoons or towels with other people. I also tell people that once they have been exposed the the cold sore virus, they can help prevent getting recurrent cold sores by wearing sunscreen to protect from sun exposure, trying to reduce stress and also by avoiding further contact with the virus.

Keeping the cold sore clean and moist is essential. It is important to keep it clean by gently washing it with warm water and trying not to touch or pick at it with your fingers. It is also very important to keep it moist with products such as Vaseline to prevent the cold sore from drying out.

If it is painful, I recommend for people to try either a topical anesthetic like Orajel or Anbesol which contain the medication benzocaine or an oral analgesic like acetaminophen (Tylenol) or ibuprofen (Advil, Motrin). Some early studies have suggested that taking acetylsalicylic acid (Aspirin) may shorten the duration of the cold sore, but it’s too early to recommend this as a treatment.

There are many other over-the-counter products marketed for cold sore relief, but I usually don’t recommend them because most of them either don’t have enough evidence to prove that they’re beneficial or they claim to work by drying out the cold sore, which is not a recommended treatment approach.

People who have recurrent cold sores may benefit from an antiviral medication. Most of these medications require a prescription. They work best for treating cold sores if they’re used immediately at the onset of symptoms. The topical antivirals such as acyclovir (Zovirax) and the newer over-the-counter antiviral docosanol cream (Abreva) are commonly used. They need to be applied about 5 times daily, but even when used properly, their efficacy is questionable. Oral formulations of antivirals like acyclovir (Zovirax) are probably most effective. However, they also require a prescription, and although they are usually very well tolerated, they may have an increased risk of side effects as opposed to topical formulations.