You can lower your risk by only having sex with one person who also isn’t having sex with anyone else and who doesn’t have an STI, and by always using condoms.
Always use condoms to help protect yourself from catching or passing on an STI. Buy condoms that have the CE mark or BSI kite mark on the packet.
This means they've been tested to high safety standards. Condoms that don't have the CE mark or BSI kite mark won't meet these standards, so don't use them.
Used correctly condoms are a very effective method of preventing STIs.