To prevent getting a sexually transmitted disease, or STD, always avoid sex with anyone who has genital sores, a rash, discharge, or other symptoms. The only time unprotected sex is safe is if you and your partner have sex only with each other, and if it's been at least six months since you each tested negative for STDs.
Use latex condoms every time you have sex. If you use a lubricant, make sure it's water-based. Use condoms for the entire sex act. Condoms are not 100% effective at preventing disease or pregnancy. However, they are extremely effective if used properly. Learn how to use condoms correctly.
Avoid sharing towels or underclothing.
Wash before and after intercourse.
Get a vaccination for hepatitis B. This is a series of three shots.
Get tested for HIV.
If you have a problem with drug or alcohol abuse, get help. People who are drunk or on drugs often fail to have safe sex.
Consider that not having sex is the only sure way to prevent STDs
To prevent giving an STD to someone else:
Stop having sex until you see a doctor and are treated.
Follow your doctor's instructions for treatment.
Use condoms whenever you have sex, especially with new partners.
Don't resume having sex unless your doctor says it's OK.
Return to your doctor to get rechecked.
Be sure your sex partner or partners also are treated.