First of all, good for you for taking control of your sexual health by getting an IUD. Intrauterine devices (IUDs) are small pieces of plastic that are inserted into the uterus as a form of long-term contraception. A hormonal IUD uses the hormone progestin to prevent pregnancy in two ways. First, it thickens the cervical mucus that blocks and traps sperm before it is able to reach an egg. It also sometimes stops ovulation, or the release of eggs from the ovaries. There are four kinds of hormonal IUDs: Mirena, Kyleena, Liletta, and Skyla, each of which lasts for 3 to 8 years.
The good news is that hormonal and non-hormonal (copper) IUDs are more than 99% effective at preventing pregnancy. Some IUDs (Paragard, Mirena, and Liletta) can even work as emergency contraception if inserted within 5 days of having unprotected sex. In these instances they are actually even more effective than the morning after pill with a 99.9% success rate. After an IUD is inserted it is still recommended to use another form of contraception for at least 7 days.
While IUDs are very effective at preventing pregnancy they offer no protection against sexually-transmitted infections (STIs). So how can you have safe sex (or safer sex) with an IUD? Condoms and dental dams provide protection against most STIs. However, if you and your partner want to have sex without a condom or dental dam then it is important to discuss that beforehand. You should both get tested (you can find testing locations here) before having sex. It is important to be open and honest with each other about whether you are seeing other people or may have been exposed to an STI.
It is recommended that all sexually-active people (including those in monogamous relationships) get tested for STIs at least once a year. Those with multiple sexual partners may want to get tested more frequently, too.
By getting an IUD you have a huge step toward having safe sex but remember to get tested and communicate with your partner to ensure both of your safety.