What is the best birth control option for an overweight female?

Best Birth Control Options for Overweight Females

For overweight females, long-acting reversible contraceptives (LARCs) such as the etonogestrel implant or copper intrauterine device (IUD) are the most effective birth control options, as their effectiveness is not compromised by higher body weight. 1, 2

Effectiveness Considerations by Method

Highly Recommended Options

• Etonogestrel implant (Nexplanon): Shows no decrease in effectiveness in overweight or obese women, with 3-year cumulative failure rates less than 1 per 100 women-years regardless of BMI 2
• Copper IUD: Maintains excellent effectiveness across all weight categories and can also be used as emergency contraception up to 5 days after unprotected intercourse 3, 2
• Levonorgestrel IUD: Effectiveness is not compromised by higher body weight 1

Options with Potential Effectiveness Concerns

• Combined oral contraceptives (COCs): Evidence is mixed regarding effectiveness in overweight women:

  • Some studies show no association between higher BMI and decreased effectiveness 1
  • Other studies suggest potentially decreased effectiveness in women with higher BMI 1
  • If used, should be monitored carefully for effectiveness 3

• Transdermal patch: May have reduced effectiveness in obese women, with one study showing higher Pearl Index (pregnancy rate) in obese women (4.63) compared to non-obese women (2.15) 1

• Emergency contraception: Ulipristal acetate may be more effective than levonorgestrel in overweight or obese women needing emergency contraception 4

Weight Impact Considerations

• Combined oral contraceptives: No clear evidence of weight change associated with combination (estrogen + progestin) pills, though individual responses may vary 3

  • Low-dose estrogen pills (30 μg ethinyl estradiol) have not shown significant overall impact on weight, body composition, or fat distribution in studies 5

• Progestin-only methods:

  • Depot medroxyprogesterone acetate (DMPA) has been associated with weight gain in some studies 3
  • About 21% of adolescents using DMPA experience early weight gain (>5% increase at 6 months) 3

Practical Recommendations

• First-line options: Implants and IUDs should be encouraged and offered as first-line contraception for overweight women due to their maintained effectiveness 3, 2

• Avoid:

  • Combined oral contraceptives containing estrogen should be used with caution after bariatric surgery due to potential absorption issues 3
  • The transdermal patch may have reduced effectiveness in obese women 1

• Emergency contraception: If needed, consider ulipristal acetate rather than levonorgestrel for overweight women, or ideally, copper IUD placement which is the most effective emergency contraceptive option 4, 3

Special Considerations

• For adolescents: Low-dose COCs (35 μg ethinyl estradiol or less) are appropriate first-line options if hormonal methods are preferred, but LARCs offer superior effectiveness 3

• After bariatric surgery: Combined oral contraception may be less reliable due to altered absorption; long-acting reversible contraception methods are preferred 3

• Monitoring: Women using hormonal contraception who are overweight should be counseled about the importance of consistent use and potential signs of method failure 3, 1

By prioritizing methods with demonstrated effectiveness across all weight categories, overweight women can achieve reliable contraception while minimizing potential risks associated with unintended pregnancy.