HEALTH SERVICES

The shot (Depo-Provera)

What is it?
“The shot" is an injectable progestin-only prescription method of reversible birth control. It contains a hormone that is similar to the progesterone made by a woman's ovaries to regulate the menstrual cycle. The shot is also known as DMPA. The D stands for "depot," the solution in which the hormone is suspended. The hormone is medroxyprogesterone acetate. The common brand name for the DMPA shot is Depo-Provera.

A shot of can prevent pregnancy for 12 weeks. It works by:

• Most often, preventing the ovaries from releasing an egg (ovulation)

• Less often, thickens cervical mucus to prevent sperm from joining an egg

• May alter the lining of the uterus, which may prevent implantation of a fertilized egg

How effective is it?
97-99.7%

Upside

• Can be used by women who cannot take estrogen

• Can be used while breastfeeding

• Effective for 12 weeks

• Helps prevent cancer of the lining of the uterus

• No pill to take daily

• Nothing to put in place before vaginal intercourse

Downside

• Must receive shot every three months
• Pregnancies, which very rarely occur, are more likely to be ectopic (in a fallopian tube)
• May not be used continuously for more than two years unless no other method is right for you
• Takes an average of nine to 10 months — or sometimes more than a year — to get pregnant after getting the last shot

Serious problems are rare.
Tell your clinician immediately if you have:

• A new lump in your breast

• Major depression

• Severe pain in the stomach or abdomen

• Unusually heavy or prolonged vaginal bleeding

• Yellowing of skin or eyes

Women should not use the shot continuously for more than two years unless no other method is right for them.

• Women who use DMPA may have temporary bone thinning. It increases the longer they use DMPA. Bone growth begins again when women stop using the shot. Whether or not there is a complete recovery of bone mass is unknown.

• Whether or not temporary bone thinning leads to greater risk of bone fracture from osteoporosis much later in life is also unknown.

• To protect your bones, get regular exercise and get extra calcium and vitamin D — either through your diet or by using supplements.