How long does Depo-Provera (medroxyprogesterone acetate) last as a contraceptive?

Duration of Depo-Provera as a Contraceptive

Depo-Provera (medroxyprogesterone acetate) lasts for 13 weeks (3 months) as a contraceptive, with a grace period allowing administration up to 15 weeks from the previous injection without requiring additional contraceptive protection. 1

Administration and Dosing

Depo-Provera is administered in two main formulations:

• Intramuscular (IM) injection: 150 mg every 13 weeks
• Subcutaneous (SC) injection: 104 mg every 13 weeks

Both formulations have similar effectiveness and side effect profiles 1. The medication is given as:

• A single injection every 13 weeks (up to 15 weeks)
• Many healthcare providers schedule visits every 11-12 weeks for adolescents to allow for missed or delayed appointments 1

Effectiveness and Mechanism

Depo-Provera is highly effective as a contraceptive:

• Failure rate with typical use: approximately 6% in the first year 1
• Failure rate with perfect use: 0.2-0.3% 2

The contraceptive works by:

• Inhibiting secretion of gonadotropins
• Preventing follicular maturation and ovulation
• Causing endometrial thinning 2

After injection, medroxyprogesterone acetate:

• Is detected in serum within 30 minutes
• Plateaus at approximately 1.0 ng/mL for about three months
• Gradually declines thereafter 3

Timing Considerations

Initial Administration

When starting Depo-Provera:

• Can be initiated on the same day as the visit ("quick start") if the provider is reasonably certain the patient is not pregnant
• A backup method (condoms or abstinence) should be used for at least the first week 1

Return to Fertility

Important considerations regarding return to fertility:

• Ovulation resumes when medroxyprogesterone acetate levels fall below 0.1 ng/mL
• Return to fertility is delayed for several months after discontinuation
• Median time for return to ovulation is approximately 30 weeks
• 97.4% cumulative rate of return to ovulation at 12 months 4

Side Effects and Monitoring

Common side effects include:

• Menstrual cycle irregularities (present in nearly all patients initially)
• Weight gain (may be predicted by weight gain status at 6 months)
• Headache, mastalgia, hair loss, and changes in libido 1

Bone Mineral Density Considerations

• Depo-Provera causes reductions in bone mineral density
• FDA issued a black-box warning about this risk in 2004
• Substantial recovery of bone mineral density occurs after discontinuation
• ACOG does not advise limiting use to 2 years or routinely monitoring bone density
• Patients should be counseled about skeletal health measures:
  • Daily intake of 1300 mg calcium and 600 IU vitamin D
  • Regular weight-bearing exercise 1

Self-Administration Option

As of 2021, the CDC recommends:

• Self-administered subcutaneous DMPA-SC should be available as an additional approach to deliver injectable contraception
• This can improve access to contraception by removing barriers such as in-person visits
• Self-administration follows the same 13-week schedule with a 2-week grace period (up to 15 weeks) 1

Special Populations

For adolescents and those with HIV:

• Depo-Provera is appropriate for adolescents with proper counseling about side effects
• For HIV-infected individuals, levels of DMPA are not reduced by antiretroviral agents
• The medication is largely free of antiretroviral interactions 1

For patients with rheumatic diseases:

• Avoid DMPA in patients at risk for osteoporosis
• Avoid in patients with positive antiphospholipid antibodies 1

Depo-Provera remains an important contraceptive option that provides effective pregnancy prevention for a 13-week period, with a 2-week grace period, making it a convenient option for many patients who prefer a longer-acting method that doesn't require daily attention.