Medroxyprogesterone Acetate Suspension (MPA), Depo Provera®, or "The Shot"

What is MPA?

Medroxyprogesterone Acetate Suspension (also known as MPA or the birth control shot) is an injectable form of birth control that is given every 12 weeks. It uses a synthetic form of the hormone "progesterone"--which is also used in some birth control pills. Progesterone is naturally produced by the ovaries during the second half of the menstrual cycle.

MPA works similarly to "the pill" because it causes a "resting state" in the ovaries, which prevents the development of an egg. If an egg is not developed and released by the ovaries, it cannot become fertilized by sperm and you cannot become pregnant.

When Should I Get the Shot?

MPA is effective within 24 hours of an injection. You can receive it within the first 5 days of your period or after having an abortion.

Schedule of Use:

MPA injections are given between 11 and 13 weeks apart (approximately every 3 months). Therefore, you only need to worry about a birth control 4 times a year.

Effectiveness:

Perfect use failure rate in one year: .3%

Typical use failure rate in one year: 3%

Contraindications-You may not use MPA if you have the following medical conditions:

• High Blood Pressure
• Pregnancy
• Vaginal bleeding without a known reason
• Cancer of the breast or reproductive organs
• Stroke
• Blood clots in the legs, lungs, or eyes
• Serious liver disease
• Allergy to medroxyprogesterone acetate suspension or any of the following ingredients: polyethylene glycol 3350, polysorbate 80, methylparaben, or propylparaben.

Advantages

• Convenient--single injections provide up to 13 weeks of protection (3 months)
• Privacy--no packaging and cannot be seen
• Good option for women who cannot take estrogen based products
• May be using by nursing mothers
• Decreased risk of endometrial and ovarian cancers and Pelvic Inflammatory Disease (PID)
• Typical decrease of menstrual flow and cramps (some women stop having periods altogether)
• Low risk of ectopic pregnancy
• Minimal drug interactions--the only drug that decreases MPA's effectiveness is aminogluthethimide (used to suppress adrenal functions for women with Cushing's Disease)
• Fewer seizures--MPA has been found to reduce the frequency of grand mal seizures

Disadvantages

• Possible irregular periods--bleeding or spotting between periods
• No protection for sexually transmitted infections--you must use a condom if at risk
• Possible association with a decrease in the amount of minerals stored in your bones, could cause an increased risk of developing Osteoporosis.
• Can take up to a year to regain fertility/become pregnant
• Possible weight gain (average of about 5 pounds per year)
• Possible increase in acne or facial hair
• Possible decreased sex drive
• Changes in cholesterol levels--studies have shows a decrease in high density lipoprotein (HDL) and increases in total and LDL cholesterol levels in some women.
• Breast tenderness
• Mood changes
• Possible hair loss

Call your doctor if you experience any of the following while usein MPA:

• Severe headaches, blurred or double vision
• Severe depression
• Unusually heavy vaginal bleeding
• Chest pain, coughing blood, or shortness of breath
• Weakness, numbness, swelling, or severe pain in an arm or leg

Sources: Contemporary Guide to Contraception 2005; Contraceptive Technology, 2005; and Managing Contraception, 2005.