Preventing STIs

What can gay guys do to avoid acquiring and transmitting STIs?

Many STIs are passed in similar ways, through bodily fluids such as cum, blood, or discharge or sores caused by the infection.

Some STIs, like gonorrhea, chlamydia, and hepatitis B and C, can be prevented by using a condom for oral, anal, and frontal (vaginal) sex. While condoms are still your best option, other STIs, like herpes, HPV/genital warts, and syphilis might still be transferred even while using a condom, just by skin touching the part of the skin infected with the STI. A condom can only protect the skin that it’s covering.

STIs can also affect the throat, and condom use for oral sex in uncommon. Don’t panic: just get tested regularly, even if you use condoms. Communicate with your partners if anything comes up, and when you get STI testing, make sure you’re getting your throat and butt swabbed if you’re sucking dick or getting fucked.


It’s important to note that we now understand that hepatitis C can also be passed on through sex. The chances of passing it increase with condomless sex where blood, HIV and other STIs are present. You may have a higher chance of acquiring hepatitis C through sex if you have multiple partners, condomless sex, party and play (PnP), inject drugs, and if you get into fisting or ass play.

There are vaccines for hepatitis A and B as well as HPV. You can request these from your doctor or an immunization clinic. The vaccines for hep A and B are free, but the vaccine for HPV is only free for guys who are 26 and under. There is no vaccine for hepatitis C, which can be spread sexually through blood. There are highly effective treatments for hepatitis C. Talk to your doctor.

In summer of 2022, an illness called mpox (originally called monkeypox) made its way into gay men’s sexual networks worldwide. Getting vaccinated for mpox is a good idea for gay men. Learn more about mpox, and learn how to get vaccinated for it here.

For a lot more detailed information on STIs and preventing them, CATIE has a new safer sex guide that explains the chances of different STIs that come with different sex act.