Progesterone hormone can be given as an injection for the woman, called DMPA (depot medroxyprogesterone acetate). It lasts for 12 to 14 weeks before another injection is given to continue the contraception. DMPA works by stopping ovulation, as well as thickening the mucus in the cervix to prevent sperm from entering, and thinning the lining of the uterus to discourage implantation. It is about 99.8% effective.
Side effects. Possibly irregular menstrual periods, or no periods, or light spotting between periods. Periods may last longer when they do come, but are not heavier. The longer you continue DMPA, the more likely you will not have periods. Some women experience significant weight gain, headaches, loss of libido and/or depression.
Breastfeeding. You can use DMPA while breastfeeding, but it is not started until three to six weeks after giving birth. Some progesterone can pass to the baby through breast milk, but long term studies of children to teenage years have not shown any effects on their growth, intelligence or development.
Advantages of progesterone injections are:
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No need to remember to take a pill every day. |
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It is more effective than the minipill. |
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Decreases the risk of breast cancer. |
Disadvantages of progesterone injections are: