Medroxyprogesterone Dosage for Contraceptive Use
The standard dosage of depot medroxyprogesterone acetate (DMPA) for contraceptive use is 150 mg administered intramuscularly every 3 months (13 weeks). 1
Administration Details
Intramuscular (IM) DMPA
- 150 mg IM injection every 3 months (13 weeks)
- Should be administered by deep intramuscular injection in the gluteal or deltoid muscle
- Sites should be rotated with each injection
- The vial should be vigorously shaken just before use to ensure uniform suspension
- Can be given up to 2 weeks late (15 weeks from last injection) without requiring additional contraceptive protection 2
Subcutaneous (SC) DMPA
- Self-administered subcutaneous DMPA (DMPA-SC) is now recommended as an additional approach to deliver injectable contraception 2
- Same timing as IM DMPA: every 3 months (13 weeks)
- Self-administration is considered off-label according to FDA labeling but may be prescribed by healthcare providers when medically indicated 2
Timing of First Injection
To ensure the patient is not pregnant:
- First injection should be given ONLY during the first 5 days of a normal menstrual period
- OR within the first 5 days post-partum
- For postpartum mothers who exclusively breastfeed, administer during or after the sixth postpartum week 1
Efficacy and Mechanism
DMPA is highly effective due to multiple mechanisms of action:
- Inhibits the midcycle luteinizing hormone (LH) peak
- Prevents ovulation
- Thickens cervical mucus
- Causes endometrial atrophy 3
Duration of Use Considerations
- Not recommended for long-term use (longer than 2 years) unless other birth control methods are considered inadequate due to concerns about bone mineral density loss 1
- Serum concentrations plateau at about 1.0 ng/mL for about three months after injection, followed by gradual decline
- In some women, MPA can be detected in serum for up to 9 months after a single injection 3
Return to Fertility
- Return to fertility is delayed for several months after discontinuation
- Ovulation resumes when MPA levels fall below 0.1 ng/mL 3
Side Effects and Monitoring
Common side effects include:
- Irregular bleeding patterns
- Weight changes
- Headaches
- Mood changes
- Decreased bone mineral density with long-term use 1
Management of Bleeding Irregularities
For DMPA users experiencing bleeding irregularities, no specific interventions have been identified in the guidelines 2
Contraindications
DMPA is contraindicated in patients with:
- Active thrombophlebitis or thromboembolic disorders
- Cerebral vascular disease
- Known or suspected breast malignancy
- Hypersensitivity to medroxyprogesterone acetate
- Significant liver disease
- Undiagnosed vaginal bleeding 1
Important Considerations
- Body weight does not affect dosage requirements 1
- When switching from other contraceptive methods, DMPA should be given in a manner that ensures continuous contraceptive coverage 1
- Efficacy depends on adherence to the dosage schedule 1
DMPA represents an effective contraceptive option with the convenience of infrequent dosing, but patients should be counseled about potential side effects, particularly regarding menstrual changes and the potential for delayed return to fertility.