You can reduce the risk of an STI by using condoms, but no contraceptive can rule this out 100%. It is important that you deal with it correctly. Always check the expiry date and choose the right size of condom. Also make sure that the condom does not come into contact with (sharp) jewelry or nails. A safe condom can be recognized by the CE logo on the packaging. Always read the instructions on the packaging and the package leaflet first.