A Working Checklist for Contraception

The range of methods used to prevent pregnancy, hormonal and non-hormonal. Effectiveness in typical use differs substantially from effectiveness in perfect use, and the gap is largest for the methods people rely on most.

Key takeaways

• Most effective reversible methods: the implant and the hormonal and copper IUDs
• Long-acting methods: do not depend on remembering anything
• Most useful single change: Ask specifically about long-acting methods, which are the most effective.
• Commonest mistake: Assuming a method works the same in typical use as in perfect use.
• See a doctor if any of the signs under "When to speak to a doctor" below apply to you.

Do

• Ask specifically about long-acting methods, which are the most effective
• Get emergency contraception as early as possible; pharmacies sell it without a prescription
• Review your method when your circumstances or medicines change
• Continue contraception until your doctor advises it is no longer needed

Do not

• Assuming a method works the same in typical use as in perfect use
• Stopping birth control on the basis of irregular periods alone
• Combined hormonal methods without discussing migraine with aura, smoking at 35 or older, or a history of blood clots

The numbers behind the list

Those two lists follow from the published figures here.

If you change one thing

Ask specifically about long-acting methods, which are the most effective. If you only change one thing, make it that.

Related topics

• The Evidence on Contraception Choices, Without the Hype (Sexual Health)
• The Evidence on Hormonal Contraception and Health, Without the Hype (Thyroid and Hormones)
• Choosing the Right Care: What Published Guidance Supports (Preventive Care)
• What the Guidance Really Says About Cooking Methods (Healthy Recipes)

Where to go next

• Contraception: Just the Figures
• Contraception: Sorting the Evidence From the Noise
• Contraception — the reference entry
• Women's Health: The Complete Guide
• Preconception Health: What the Evidence Actually Says
• Bone Health in Women: What the Evidence Actually Says

When to speak to a doctor

Call 911 or go to the emergency room for calf pain or swelling, chest pain, severe shortness of breath, sudden severe headache, weakness on one side or vision loss while using combined hormonal contraception: these can be signs of a blood clot or stroke. Tell your prescriber about migraine with aura, smoking at 35 or older, high blood pressure or a history of clots.

Where this comes from

• CDC — U.S. Medical Eligibility Criteria for Contraceptive Use, 2024
• American College of Obstetricians and Gynecologists — Emergency Contraception

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.