Valaciclovir.
When one partner has herpes simplex infection and the other doesn't, the use of valaciclovir, in conjunction with a condom, has been demonstrated to further decrease the chances of transmission to the uninfected partner, and the FDA approved this as a new indication for the drug in August 2003.Other measures that have been suggested include:
- Use of a lip protectant or lip gloss
- Management of stress
- Adequate sleep and nutrition
- Avoidance of cross-infecting different sites on the body if HSV blisters are present

