It's certainly possible. You can reduce the risk to a partner by having sex only when you have no symptoms of genital herpes. However, the virus can still be contagious without any noticeable symptoms such as sores or a rash on the skin. That's why you should always use a latex condom. A condom does not completely eliminate the risk, because it may not cover an affected area, but it does offer some protection.
Taking antiviral medications acyclovir (Zovirax), Valtrex, and Famvir can make symptoms appear less often and make them less severe. There is some evidence that these drugs also may protect against transmission.