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Diaphragm 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 October 11, 2026Updated October 11, 2026

Side-by-side comparison

Diaphragm A reusable silicone dome that covers the cervix to block sperm, used with spermicide each time you have sex.
Fertility Awareness Tracking body signs like temperature and cervical mucus to identify fertile days and avoid unprotected sex then.

Method	Diaphragm A reusable silicone dome that covers the cervix to block sperm, used with spermicide each time you have sex.	Fertility Awareness Tracking body signs like temperature and cervical mucus to identify fertile days and avoid unprotected sex then.
Efficacy	Diaphragm 83% typical use Least effective: under 90 out of 100 people successfully prevent pregnancy per year.	Fertility Awareness Least effective
Cost	Diaphragm $0–$250 Insurance: Usually	Fertility Awareness $0–$20 Insurance: Varies
Duration	Diaphragm Reusable for up to 2 years (replace sooner if damaged)	Fertility Awareness Ongoing daily tracking
Reversibility	Diaphragm Reversible	Fertility Awareness Reversible
STI protection	Diaphragm No	Fertility Awareness No
How it works	Diaphragm A reusable silicone dome covers the cervix to block sperm from reaching an egg. Used with spermicide for added effectiveness.	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.
Prescription	Diaphragm Required Hybrid (Fitting or Ship)	Fertility Awareness Not required Self-Directed
Side effects	Diaphragm Increased risk of urinary tract infection Vaginal irritation from spermicide Toxic shock syndrome risk (rare)	Fertility Awareness None reported
Who shouldn't use this	Diaphragm Uterine or cervical anomaly preventing fit 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)	Fertility Awareness Irregular cycles that make fertile window prediction unreliable Inability to track consistently Recent childbirth, breastfeeding, or perimenopause (cycles unstable)

Key differences

How long it lasts: Diaphragm, reusable for up to 2 years (replace sooner if damaged); Fertility Awareness, ongoing daily tracking. A prescription is needed for Diaphragm, not for Fertility Awareness. Diaphragm: costs $0–$250. Fertility Awareness: costs $0–$20.