Treatments for herpes (oral and genital) have been available for decades. The first highly effective medication was Acyclovir. It proved effective in shortening outbreaks and was a boon at a time when so little seemed to work. In those early days having anything that could shorten an outbreak and even prevent them changed how people saw the disease.
Acyclovir worked in a very targeted way against Herpes DNA. In reality, there isn’t much more to a virus than its DNA and the proteins that cover it. Acyclovir works by preventing the herpes virus from replicating its DNA. This effect can prevent outbreaks and decrease viral shedding if taken daily. It can also abort or shorten an outbreak when taken at the onset of symptoms.
One limitation was that acyclovir was limited in how much could be absorbed through the intestines. Only 20% of it was ever used by the body. This limitation was overcome by creating something called a prodrug of acyclovir. Valacyclovir was created by modifying the acyclovir molecule slightly. This makes the drug absorb much better in the digestive tract. Once absorbed, valacyclovir is converted to acyclovir in the body where it is effective at combating the herpes virus. Twice a day or even once a day valacyclovir works better than 3–5 times/day of acyclovir. Another drug, famciclovir, uses the same concept to help penciclovir enter the body.
This information is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.