Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, said the action complied with the April 5 order of the U.S. District Court in New York to make the levonorgestrel-containing emergency contraceptives available as an over-the-counter product without age or other restrictions.
Plan B One-Step is an emergency contraceptive intended to reduce the chance of pregnancy following unprotected sexual intercourse or a known or suspected contraceptive failure such as a condom.
The primary mechanism of action of levonorgestrel as a progestogen-only emergency contraceptive pill is to prevent fertilization by inhibition of ovulation.
A single-dose pill -- 1.5 milligram tablet -- is effective in decreasing the chance of pregnancy and should be taken as soon as possible within three days after unprotected sex, Woodcock said.
Plan B One-Step was first approved by the FDA in July 2009 for use without a prescription for women age 17 and older and as a prescription-only option for women younger than age 17, Woodcock said.
In April, the product was approved for non-prescription use for women age 15 and older.
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