Most cold sores heal on their own without prescription medicines. But some antiviral medicines (such as acyclovir or famciclovir) when taken orally (tablets) may
be helpful in reducing the frequency and severity of attacks of
Doctors may prescribe oral antiviral medicines that
can be taken daily to prevent future outbreaks of cold sores. These medicines
may also be given during periods of increased risk of getting cold sores
(such as during cosmetic surgery or sun exposure).
Famciclovir (Famvir) is sometimes used to treat the herpes virus that causes
cold sores and genital herpes (as well as the virus that causes shingles). This medicine is available only by
prescription and is taken orally in tablet form.
If you are pregnant or nursing, you should talk with your doctor
before taking famciclovir.
This medicine is not recommended for people who have had an
allergic reaction to it in the past.
Possible mild side effects include itching, fever, headache,
fatigue, nausea, or diarrhea.
Valacyclovir (Valtrex) capsules are available by prescription only.
Valacyclovir was approved by the U.S. Food and Drug Administration (FDA) as a
1-day treatment to reduce cold sore duration in people 12 years and
older.2 It is absorbed by the body much better than
some other antiviral medicines (such as acyclovir).