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Cervical Cap vs Copper IUD

A side-by-side comparison of two birth control methods — efficacy, cost, how they work, and who shouldn't use them.

Last verified October 11, 2026Updated October 11, 2026

Side-by-side comparison

Cervical Cap A small silicone cap that fits over the cervix by suction, used with spermicide before sex.
Copper IUD A small copper device placed in the uterus that works for up to 10 years and is over 99% effective.

Method	Cervical Cap A small silicone cap that fits over the cervix by suction, used with spermicide before sex.	Copper IUD A small copper device placed in the uterus that works for up to 10 years and is over 99% effective.
Efficacy	Cervical Cap 78% typical use Least effective: under 90 out of 100 people successfully prevent pregnancy per year.	Copper IUD 99.2% typical use Most effective: over 99 out of 100 people successfully prevent pregnancy per year.
Cost	Cervical Cap $0–$90 Insurance: Usually	Copper IUD $0–$1,167 Insurance: Usually
Duration	Cervical Cap Reusable for up to 2 years (replace sooner if worn or damaged)	Copper IUD Up to 10 years
Reversibility	Cervical Cap Reversible	Copper IUD Reversible
STI protection	Cervical Cap No	Copper IUD No
How it works	Cervical Cap A small silicone cap fits snugly over the cervix and stays in place by suction, blocking sperm from entering the cervix. Used with spermicide inside the cap.	Copper IUD Releases copper into the uterus, which interferes with sperm movement and fertilization and may prevent implantation.
Prescription	Cervical Cap Required Hybrid (Fitting or Ship)	Copper IUD Required In-Person Procedure
Side effects	Cervical Cap Vaginal irritation from spermicide Unusual vaginal discharge Toxic shock syndrome risk if worn during a period	Copper IUD Heavier or longer periods (especially first few months) Increased cramping Spotting between periods Small risk of uterine perforation at insertion
Who shouldn't use this	Cervical Cap Cervical anomaly preventing fit Active pelvic infection Sensitivity to silicone or spermicide Inability to insert or remove reliably History of toxic shock syndrome High risk of HIV exposure (because of the spermicide)	Copper IUD Active pelvic infection or PID (FDA label) Uterine abnormality that distorts the uterine cavity (FDA label) Wilson's disease (copper metabolism disorder) (FDA label) Known copper allergy (FDA label) Current pregnancy (FDA label)

Key differences

With typical use, 22 in 100 people using Cervical Cap get pregnant in a year, vs 0.8 in 100 with Copper IUD (least effective vs most effective). How long it lasts: Cervical Cap, reusable for up to 2 years (replace sooner if worn or damaged); Copper IUD, up to 10 years. Cervical Cap: costs $0–$90. Copper IUD: costs $0–$1,167.