Birth Control Options Compared: Effectiveness and Side Effects

You want birth control that works, fits your life, and does not cause side effects you hate. There are many options: pills, patches, rings, shots, IUDs, implants, and condoms. Friends swear by different ones. It can be hard to compare them.

This guide lines up the main methods by how well they work in real life. It also explains the side effects and the health factors that clinicians check.

How effective is each method?

The numbers below are typical-use failure rates. They show how many out of 100 people get pregnant in the first year of use, including mistakes such as missed pills.[1][5]

• Implant (a small rod in the arm): about 0.1 in 100.
• Hormonal IUD (levonorgestrel): about 0.1 to 0.4 in 100.
• Copper IUD: about 0.8 in 100.
• Tubal sterilization: about 0.5 in 100. Vasectomy: about 0.15 in 100.
• Injection (shot every 3 months): about 4 in 100.
• Pill, patch, or ring: about 7 in 100.
• Diaphragm: about 17 in 100.
• External (male) condom: about 13 in 100.
• Internal (female) condom: about 21 in 100.
• No method: about 85 in 100.[5]

The pattern is clear. Methods that you do not have to remember each day or each time work best.

What your doctor looks at

Clinicians use eligibility criteria to match methods with your health. In the US, this is the CDC's US Medical Eligibility Criteria (US MEC), updated in 2024.[2] In Canada, clinicians use the SOGC Canadian Contraception Consensus.[3][4] Both rate each method for each health condition, from "no restriction" to "unacceptable health risk."

Methods with estrogen

The combined pill, patch, and ring contain estrogen and a progestin. Estrogen raises the risk of blood clots. The risk is still lower than the clot risk during pregnancy and after birth.[3]

Both guidelines advise against estrogen methods for people who:[2][3]

• Are 35 or older and smoke.
• Have migraine with aura.
• Have had a blood clot, stroke, or heart attack.
• Have high blood pressure that is not well controlled.
• Have certain liver diseases or breast cancer.
• Gave birth recently, in the first weeks after delivery.

Progestin-only and non-hormonal methods

Progestin-only methods include the implant, hormonal IUD, injection, and progestin-only pill. They do not carry the same clot risk, so they suit many people who cannot use estrogen. The copper IUD has no hormones.[2]

Common side effects

• Combined pill, patch, ring: spotting in the first months, nausea, breast tenderness. Many people get lighter, more regular periods.
• Hormonal IUD: irregular spotting at first, then lighter periods. Some users stop having periods.[4]
• Copper IUD: heavier or more painful periods for some users.[4]
• Implant: unpredictable bleeding is the most common reason people stop using it.
• Injection: irregular bleeding, possible weight gain, and a delay of several months in return of fertility after stopping. It can lower bone density while in use, which usually recovers after stopping.

Benefits beyond birth control

Some methods treat other problems. Hormonal IUDs reduce heavy menstrual bleeding. Combined methods can improve acne, reduce period pain, and lower the risk of ovarian and endometrial cancer over time.[3]

Emergency contraception

Emergency contraception can prevent pregnancy after unprotected sex or a method failure, such as a broken condom.[1]

• Copper IUD: the most effective option. It can be inserted within 5 days and then used as ongoing birth control.
• Emergency contraceptive pills: can be taken up to 5 days after sex, but work better the sooner they are taken.[1]
• Levonorgestrel pills are available without a prescription in both Canada and the US. They may work less well in people with higher body weight. Ask a pharmacist which option fits you.

Canada and the US: access differs

The medical guidance is very similar. Access is not. In the US, one progestin-only pill has been approved for sale without a prescription since 2023. In Canada, pharmacists in several provinces can now prescribe hormonal birth control. Coverage for birth control varies by province, state, and insurance plan, and public coverage in some provinces has expanded in recent years.

How to choose

There is no single best method. Clinicians help you weigh:

• How important it is to avoid pregnancy right now.
• Whether you want a method you do not have to think about.
• How you feel about changes in bleeding.
• Whether you can use estrogen safely.
• How soon you may want to become pregnant.
• Cost, coverage, and how easy it is to get the method.

Questions to ask your clinician

• Which methods are safe for me, given my health history?
• How well will each method work with the way I live?
• What bleeding changes should I expect?
• Can this method also help my period pain, acne, or heavy bleeding?
• How quickly can I get pregnant after I stop?
• What should I do if I miss a pill or am late for a shot?
• Do I also need condoms to prevent infections?

When to get care quickly

Call 911 or go to the emergency department if you use a hormonal method and have:

• Sudden chest pain or shortness of breath.
• Pain and swelling in one leg.
• A sudden severe headache, vision loss, weakness, or trouble speaking.
• Severe belly pain, especially with a positive pregnancy test.

Bottom line

The implant and IUDs prevent pregnancy best because they do not depend on daily use. Pills, patches, and rings work well but fail more often in real life. Estrogen methods are not safe for everyone, and clinicians in both countries use detailed eligibility guides to help you choose. Condoms remain the only method that protects against infections.

Primary AI can show you the guideline and study sources behind this topic in plain language, so you can bring better questions to your appointment.