The birth control shot, also known as Depo-Provera or DMPA, is a type of hormone birth control. The birth control shot is administered in the woman's upper arm or buttocks, according to Epigee.org (see References below).
Hormones
According to Planned Parenthood, the birth control shot contains a large dose of progestin, which is a synthetic form of progesterone.
Pregnancy Prevention
Planned Parenthood notes that the birth control shot prevents pregnancy in three ways: suppressing ovulation, thickening the cervical mucus and thinning the uterine lining.
Duration
According to Epigee.org, the birth control shot contains enough hormones to prevent pregnancy for 12 weeks, which is beneficial for women who do not want to take a daily birth control pill.
Effectiveness
When the birth control shot is administered every 12 weeks, the shot is nearly 100 percent effective, according to Planned Parenthood. If the woman has a gap in between birth control shots, the effectiveness drops to 97 percent.
Side Effects
Epigee.org says that women experience more side effects with the birth control shot because of the large dose of hormones. Side effects include menstrual changes, weight gain, dizziness, breast tenderness, change in libido, headaches and changes in facial and body hair.
