Compare

Copper IUD vs Fertility Awareness

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

Last verified Updated

Side-by-side comparison

  • Copper IUD A small copper device placed in the uterus that works for up to 10 years and is over 99% effective.
  • Fertility Awareness Tracking body signs like temperature and cervical mucus to identify fertile days and avoid unprotected sex then.
Method
Copper IUD A small copper device placed in the uterus that works for up to 10 years and is over 99% effective.
Fertility Awareness Tracking body signs like temperature and cervical mucus to identify fertile days and avoid unprotected sex then.
EfficacyCopper IUD 99.2% typical use

Most effective: over 99 out of 100 people successfully prevent pregnancy per year.

Fertility Awareness Least effective
CostCopper IUD $0–$1,167 Insurance: UsuallyFertility Awareness $0–$20 Insurance: Varies
DurationCopper IUD Up to 10 yearsFertility Awareness Ongoing daily tracking
ReversibilityCopper IUD ReversibleFertility Awareness Reversible
STI protectionCopper IUD NoFertility Awareness No
How it worksCopper IUD

Releases copper into the uterus, which interferes with sperm movement and fertilization and may prevent implantation.

Fertility Awareness

Track basal body temperature, cervical mucus, and cycle length to identify the fertile window. Avoid unprotected sex or use backup contraception on fertile days.

PrescriptionCopper IUD Required In-Person ProcedureFertility Awareness Not required Self-Directed
Side effectsCopper IUD
  • Heavier or longer periods (especially first few months)
  • Increased cramping
  • Spotting between periods
  • Small risk of uterine perforation at insertion
Fertility Awareness None reported
Who shouldn't use thisCopper 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)
Fertility Awareness
  • Irregular cycles that make fertile window prediction unreliable
  • Inability to track consistently
  • Recent childbirth, breastfeeding, or perimenopause (cycles unstable)

Key differences

Copper IUD is most effective; Fertility Awareness is least effective. How long it lasts: Copper IUD, up to 10 years; Fertility Awareness, ongoing daily tracking. A prescription is needed for Copper IUD, not for Fertility Awareness. Copper IUD: costs $0–$1,167. Fertility Awareness: costs $0–$20.