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.

Side-by-side comparison

Method
Copper IUD

Copper IUD

A small copper device placed in the uterus that works for up to 10 years and is over 99% effective.
Fertility Awareness

Fertility Awareness

Tracking body signs like temperature and cervical mucus to identify fertile days and avoid unprotected sex then.
Efficacy99.2% typical use

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

Least effective see details

Least effective: under 90 out of 100 people successfully prevent pregnancy per year.

Cost$0–$1,424

Insurance: Usually

$0–$100 /monthly

Insurance: Varies

DurationUp to 10 yearsOngoing daily tracking
ReversibilityReversibleReversible
STI ProtectionNoNo
How it works

Releases copper ions into the uterus that make the environment toxic to sperm and may prevent implantation if fertilization occurs.

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

PrescriptionRequired Prescription requiredOTC No prescription / OTC
Available Products5 products4 products
Side effects
  • Heavier or longer periods (especially first few months)
  • Increased cramping
  • Spotting between periods
  • Small risk of uterine perforation at insertion
None reported
Who shouldn't use this
  • Active pelvic infection or PID (FDA label Category 4)
  • Uterine anomaly preventing insertion (FDA label Category 4)
  • Wilson's disease (copper metabolism disorder) (FDA label Category 4)
  • Known copper allergy (FDA label Category 4)
  • Current pregnancy (FDA label Category 4)
  • Irregular cycles that make fertile window prediction unreliable
  • Inability to track consistently
  • Recent childbirth, breastfeeding, or perimenopause (cycles unstable)