Avoid SexThe most effective way to avoid STIs is to abstain from sex.
Stay with 1 uninfected partner. A safe and sensible way of avoiding STIs is to stay in a long-term faithful relationship with a partner who isn't infected (ensure both parties have been tested before commencing a sexually active relationship).
Get vaccinated.Getting vaccinated before sexual encounters is also effective in preventing certain types of STIs. Vaccines are available to prevent two viral STIs that can cause cancer — human papillomavirus (HPV), hepatitis A and hepatitis B. The Centers for Disease Control and Prevention (CDC) recommends the HPV vaccine for girls and boys ages 11 and 12. If not fully vaccinated at ages 11 and 12, the CDC recommends that girls and women through age 26 and boys and men through age 26 receive the vaccine. The hepatitis B vaccine is usually given to newborns.
Wait and verify. Avoid vaginal and anal intercourse with new partners until you have both been tested for STIs. Oral sex is less risky, but use a latex condom or dental dam to prevent direct contact between the oral and genital mucous membranes. Keep in mind that human papillomavirus (HPV) screening isn't available for men, and no reliable screening test exists for genital herpes, so you may not be aware you're infected until you have symptoms. It's also possible to be infected with an STI yet still test negative.
Use condoms and dental dams consistently and correctly. Use a new condoms or dental dam for each sex act, whether oral, vaginal or anal. Never rely on oil-based lubricants, such as petroleum jelly, with a latex condom or dental dam. Keep in mind that while condoms reduce your risk of exposure to most STIs, they provide a lesser degree of protection for STIs involving exposed genital sores, such as human papillomavirus (HPV) or herpes. Also, oral contraceptives or intrauterine devices, don't protect against STIs.
Don't drink alcohol excessively or use drugs. If you've drunk excessively you're more likely to take sexual risks.
Avoid anonymous, casual sex. Don't look for sex partners online or in bars or other pickup places. Not knowing your sex partner or their history / background well will increase your risk of possible exposure to an STI.
Communicate. Before any serious sexual contact, communicate with your partner about practicing safer sex. Make sure you are in agreement with a safe sex practice.
Teach your child. Educating your children early of the risks and physical complications of STI's is essential.
Consider male circumcision. Research has proven that male circumcision can help reduce a man's risk of acquiring HIV from an infected woman (heterosexual transmission) by 50 to 60 percent. Male circumcision may also help prevent transmission of genital HPV and genital herpes.