Fertility Awareness
vs
Internal Condom

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	Fertility Awareness Tracking body signs like temperature and cervical mucus to identify fertile days and avoid unprotected sex then.	Internal Condom A soft pouch worn inside the vagina that blocks sperm and protects against STIs, available over the counter.
Efficacy	Least effective see details Least effective: under 90 out of 100 people successfully prevent pregnancy per year.	79% typical use Least effective: under 90 out of 100 people successfully prevent pregnancy per year.
Cost	$0–$100 /monthly Insurance: Varies	$2–$4 /per unit Insurance: Varies
Duration	Ongoing daily tracking	Single use
Reversibility	Reversible	Reversible
STI Protection	No	Yes
How it works	Track basal body temperature, cervical mucus, and cycle length to identify the fertile window. Avoid unprotected sex or use backup contraception on fertile days.	A soft, loose-fitting nitrile pouch lines the vagina and collects semen. The inner ring anchors it at the cervix and the outer ring stays outside the vaginal opening.
Prescription	OTC No prescription / OTC	OTC No prescription / OTC
Available Products	4 products	1 product
Side effects	None reported	Mild irritation or discomfort Noise during use if not positioned correctly Slippage with incorrect insertion
Who shouldn't use this	Irregular cycles that make fertile window prediction unreliable Inability to track consistently Recent childbirth, breastfeeding, or perimenopause (cycles unstable)	Sensitivity to nitrile (rare)