What are the risks and efficacy of using Plan B (levonorgestrel) 1-2 times a week as a primary form of contraception in a female patient of reproductive age with no known history of hormonal sensitivities or other medical conditions?

Plan B Should Not Be Used 1-2 Times Weekly as Primary Contraception

Plan B (levonorgestrel 1.5 mg) is explicitly designed as emergency contraception only and should not be used as a regular birth control method because it is significantly less effective than standard contraceptive options. 1

Why This Practice Is Problematic

Efficacy Concerns

• Emergency contraception prevents only about 7 out of 8 expected pregnancies (approximately 85% efficacy) when used correctly after a single act of unprotected intercourse 2, 1
• This efficacy rate is substantially lower than regular contraceptive methods, which have typical-use failure rates of less than 9% annually for combined hormonal contraceptives and even lower for long-acting reversible contraception 2
• Repeated use 1-2 times weekly would result in cumulative pregnancy risk far exceeding that of any approved primary contraceptive method 1, 3

FDA Labeling and Guidelines

• The FDA-approved labeling for levonorgestrel explicitly states it "should not be used as a regular birth control method, because it's not as effective as regular birth control" 1
• CDC guidelines confirm that any contraceptive method may be started after completion of emergency contraceptive pills, with the clear implication that ongoing contraception should replace emergency use 2

Safety Profile with Repeated Use

While levonorgestrel has an excellent safety profile for occasional emergency use 4:

• There is no established safety data for using Plan B 1-2 times weekly as the evidence base and regulatory approval are limited to occasional emergency use 1, 4
• The hormone exposure pattern differs significantly from continuous or cyclic hormonal contraception, making extrapolation of safety data inappropriate 3
• Common side effects include menstrual irregularities, nausea, abdominal pain, fatigue, headache, and breast tenderness—which would be experienced repeatedly with frequent use 1

Recommended Alternative Approach

Immediate Counseling

This patient requires counseling about and initiation of an appropriate primary contraceptive method 2:

• Long-acting reversible contraception (LARC) methods including levonorgestrel IUDs, copper IUDs, or etonogestrel implants are Category 1 (no restrictions) for most reproductive-age women and offer the highest efficacy 2
• Combined hormonal contraceptives (pills, patch, or ring) are highly effective with typical-use failure rates of approximately 9% 2
• Progestin-only pills are Category 1 for most women and particularly appropriate for those with contraindications to estrogen 2, 5

Addressing Barriers

If the patient is using Plan B repeatedly due to access issues or relationship dynamics:

• Explore why regular contraception is not being used—this may reveal important barriers including partner resistance, cost concerns, or lack of knowledge about options 2
• Advance provision of emergency contraception can be offered as a backup while establishing reliable primary contraception 2
• Condoms should be recommended in addition to any hormonal method for STI protection, as emergency contraception provides no protection against sexually transmitted infections 2, 1

Clinical Pitfalls to Avoid

• Do not normalize this practice by simply providing repeated prescriptions without addressing the underlying contraceptive need 1, 3
• A pelvic exam is not required to prescribe oral contraceptives, so lack of examination should not be a barrier to initiating appropriate contraception 2
• Consider that frequent need for emergency contraception may indicate reproductive coercion or intimate partner violence requiring additional assessment and resources 2

Bottom Line

The patient should be transitioned immediately to an evidence-based primary contraceptive method with documented efficacy for ongoing use. Plan B's role is strictly as backup contraception after method failure or unprotected intercourse, not as a weekly contraceptive strategy 1, 3. The significantly higher pregnancy risk with this approach, combined with lack of safety data for frequent repeated use, makes this practice medically inappropriate 1, 4, 3.