Condoms prevent partners from sharing fluids such as semen and vaginal fluids, and they prevent skin-to-skin contact between partners in the places they are most likely to have STDs, such as on the shaft of the penis or the labia.

Condoms lower the chances of getting or giving a skin-to-skin STD, such as herpes or HPV, but they can’t completely eliminate the risk. Condoms can’t prevent infections from spreading if a person has an infection on the skin not covered by the condom. For example, if a person has a herpes sore on their upper thigh, then his or her partner could rub against it and also become infected with herpes.