Copper coil percentage: what the numbers mean

When people ask about a copper coil percentage, they usually mean how reliably it prevents pregnancy. The device releases copper inside the womb. This changes the local environment so sperm movement and fertilisation are less likely. It does not protect against sexually transmitted infections, and it does not contain contraceptive hormones.

A percentage cannot predict one individual’s experience. Protection can be affected if the coil is expelled or is not positioned correctly. Bleeding and cramps may be stronger during the first months, and periods can remain heavier for some people. A pregnancy test is appropriate if a period is late or pregnancy symptoms occur.

A trained clinician places the copper coil through the cervix into the womb and confirms the follow-up plan. After placement, learn how the two fine threads feel near the cervix. Checking them occasionally can help you notice a change, although not feeling them does not prove that the coil has moved. Use condoms for infection protection and arrange a review if the threads feel different, the device seems to be coming out, or pain and bleeding are difficult to manage.

If you want a hormone-free option, discuss the copper coil’s duration, bleeding pattern and suitability with a clinician. A hormonal coil is another intrauterine option with a different hormone and bleeding profile.

Get urgent medical advice for severe or worsening lower-abdominal pain, fainting, fever, unusual or foul-smelling discharge, very heavy bleeding, or a positive pregnancy test while the coil is in place. These symptoms need assessment for problems such as infection, pregnancy outside the womb or a device that has moved. Contact a clinician promptly if you cannot feel the threads, feel hard plastic at the cervix, or suspect the coil has come out.

Ask: Is a copper coil suitable for my bleeding pattern and medical history? How will placement and thread checks work? Which symptoms should bring me back sooner? What is the plan if I want it removed or want to change to a hormonal method?