Injectable hormonal contraceptives contain progesterone or combination of estrogens for parenteral (intramuscular or IM) administration with long-term hormone doses.
It consists in the administration of progesterone alone, parenterally (MI), with contraceptive effect for periods of 1 or 3 months, or a monthly combination of estrogen and progesterone for parenteral (MI).
What are the chances that the injection will fail?
The monthly injection failure rate ranges from 0.1% to 0.6%, meaning that out of every 1,000 women who use it for one year, one to six get pregnant. The quarterly injection failure rate is 0.3%, that is, out of every 1,000 women who use it for one year, only three get pregnant.
Can the injection be bad for your health?
- Changes in the menstrual cycle: minor bleeding between periods, prolonged bleeding, and amenorrhea (no menstruation)
- Weight gain
- Mild headache