Updated

Implanon, a rod-shaped contraceptive implanted in the upper arm for up to three years, received federal approval, health officials said Tuesday.

Food and Drug Administration approval clears Organon USA to sell the birth control rod in the United States, agency spokeswoman Susan Cruzan said. Implanon, which can stop menstruation in many women, has been sold in more than 30 countries since 1998.

The matchstick-sized implant releases a low, steady dose of progestin to prevent pregnancy. The rod is inserted by a doctor under the skin of the upper arm. It can be removed at any time, according to the company, a unit of Netherlands-based Akzo Nobel.

Progestin is a synthetic hormone similar to the progesterone made in the ovaries. The hormone typically acts on the body by thickening the mucus in a women's cervix, preventing the union of sperm and egg. It also can prevent ovulation, or the release of an egg from the ovaries.

Organon claims the implant provides 99 percent contraceptive protection.

Its approval comes six years after Wyeth Pharmaceuticals stopped U.S. sales of another implant, Norplant. Norplant worked for up to seven years, or four years more than Implanon, but spawned lawsuits by women injured having its six rods removed or disturbed by side effects.

Another implant, a two-rod product called Jadelle, received FDA approval in 1996 but has never been sold in the U.S.

Use of Implanon can cause irregular bleeding and spotting, as well as no bleeding at all.

Implanon, along with other hormonal contraceptives, is associated with an increased risk of several serious side effects like blood clots. Smoking can further increases those risks.

Other hormonal birth control methods include the pill, patch, vaginal ring and a shot, called Depo-Provera, which provides three months of protection.

Organon did not release the price of Implanon. Spokeswoman Frances DeSena said it would be comparable to the monthly cost of other hormonal methods.

The implant will be available only through specially trained doctors; the company intends to start training in August, DeSena said.