What are the options for progestin-only (Progesterone) contraception?

Progestin-Only Contraceptive Options

Progestin-only contraceptives offer several highly effective options for pregnancy prevention, with long-acting reversible contraceptives (LARCs) such as intrauterine devices (IUDs) and implants being the most effective choices with failure rates less than 1%. 1

Long-Acting Reversible Contraceptives (LARCs)

Progestin IUDs

• Levonorgestrel IUDs: Highly effective (failure rate <1%) 1
  • Available in different versions effective for 3-7 years depending on the specific product 1, 2
  • May decrease or eliminate menstrual bleeding 1
  • Recent research shows the 52-mg levonorgestrel IUD maintains high contraceptive efficacy for up to 8 years 2
  • Advantages: No daily adherence required, reversible, may improve heavy menstrual bleeding
  • Potential side effects: Irregular bleeding initially, although many users experience lighter periods or amenorrhea over time

Subdermal Implants

• Etonogestrel implant (single rod): Highly effective with lowest failure rate (0.05%) 1, 3

  • Effective for up to 3 years (with evidence supporting extended use up to 5 years) 3
  • Minimal to no bone loss 1
  • Advantages: Highest efficacy of all contraceptive methods, discrete, no daily adherence
  • Potential side effects: Irregular bleeding patterns, which is the most common reason for discontinuation

• Levonorgestrel implant (two-rod system): Similar efficacy to etonogestrel implant 4

  • Effective for 5 years 5
  • Advantages: Longer duration of action than etonogestrel implant
  • Potential side effects: Similar to etonogestrel implant, including irregular bleeding

Short-Acting Progestin-Only Methods

Progestin-Only Pills

• Effectiveness: 92-95% with typical use (5-8% failure rate) 1, 6
• Works primarily by thickening cervical mucus 1
• Requires strict adherence to timing (must be taken at same time daily) 1
• Advantages: No estrogen-related side effects, safe for those with contraindications to estrogen
• Potential side effects: Irregular bleeding, requires disciplined daily use at the same time

Depot Medroxyprogesterone Acetate (DMPA) Injection

• Effectiveness: 97% with typical use (3% failure rate) 1
• Administered every 12 weeks 1
• Advantages: No daily adherence, private
• Potential side effects: Irregular bleeding, potential bone mineral density concerns with long-term use 1
• Should be avoided in patients at risk for osteoporosis 1

Emergency Contraception Options

Progestin-Only Emergency Contraception

• Levonorgestrel emergency contraception (1.5 mg single dose) 1
• Most effective when taken as soon as possible within 5 days of unprotected intercourse 1
• May be less effective in women with BMI >30 kg/m² 1
• Advantages: Available over-the-counter, no prescription needed
• Note: Ulipristal acetate (not progestin-only) may be more effective than levonorgestrel after 72 hours and for women who are overweight 1

Copper IUD for Emergency Contraception

• Can be inserted within 5 days of unprotected intercourse 1
• Highest efficacy of all emergency contraception methods (<1% failure rate) 1
• Provides ongoing contraception for up to 10 years 1

Special Considerations

Safety Profile

• Progestin-only methods are generally safer than combined hormonal contraceptives for women with certain medical conditions 1, 7
• Particularly beneficial for women with:
  • History of venous thromboembolism (VTE) 7
  • Positive antiphospholipid antibodies 1, 7
  • Decompensated cirrhosis 1
  • Liver transplant recipients with graft failure 1

Efficacy in Special Populations

• Adolescents: LARCs are particularly recommended due to high efficacy and no need for daily adherence 1
• Women with rheumatic diseases: Progestin-only methods are often preferred, especially with positive antiphospholipid antibodies 1
• Women taking teratogenic medications (e.g., mycophenolic acid): IUDs or combination of two other contraceptive methods recommended 1

Comparison of Failure Rates (Typical Use)

• Implants: <1% 1
• Levonorgestrel IUD: <1% 1
• DMPA injection: 3% 1
• Progestin-only pills: 5-8% 1, 6

Common Pitfalls and Considerations

• Irregular bleeding is the most common side effect and reason for discontinuation of progestin-only methods 5, 3
• Progestin-only pills require strict adherence to timing for maximum effectiveness 1
• Weight may affect efficacy of some progestin-only emergency contraception methods but does not appear to affect implant efficacy 4
• Proper counseling about expected bleeding changes can improve continuation rates

Progestin-only contraceptives provide excellent options for women who cannot or prefer not to use estrogen-containing methods, with LARCs offering the highest efficacy and convenience for most users.