Depo-Provera
Depo-provera is a type of long-term birth control. After a painless exam, a doctor injects synbthtic progestin hormones in the upper arm or behind. Depo-provera gives three months of protection from conception. It does not, however, protect against STI's or HIV. Condoms should still be used for STI and HIV protection. Since Depo-provera is injected and remains in the user's body for the entire three-month period, it cannot be removed before that time if any unpleasant side effects occur or if conception is desired. After three months, it must be injected again to prolong contraception. The entire procedure costs approximately $40 per shot.
Depo-provera works by suppressing FSH and LH levels through hormones. These hormones are progestin. No estrogen is used. Progestin prevents ovulation and changes the cervical mucus so that sperm cannot pass through the cervix. Its full strength does not peak until two weeks after the first shot, so an additional method of contraception should be used at first.
Common side effects include weight gain, irregular or light periods, breast tenderness, bone density decrease, reduced risk of PID, endometrical and ovarian cancers. Many users experience a delay in fertility of a year or more after their last shot. If you are considering becoming pregnant before this time, you should reconsider the use of depo-provera.
Sources:
"Depo-provera," http://www.columbia.edu/cu/healthwise/0721.html, 11/13/97.
"Depo-prvera backup," http://www.columbia.edu/cu/healthwise/0455.html, 11/13/97.
"Norplant vs. Progestin-only Pill," http://www.columbia.edu/cu/healthwise/0691.html, 11/13/97.
"Norplant Information," http://www.columbia.edu/cu/healthwise/0647.html, 11/13/97.