A new "morning after" pill that can be taken up to five days after a sexual encounter is safe, efficient, and presents no unexpected side effects, US regulatory staff said in a report out Tuesday.
The report from Food and Drug Administration (FDA) staff comes ahead of a Thursday review by a panel that will issue a recommendation on approving the drug ulipristal -- produced by French pharmaceutical HRA Pharma -- for sale in the United States.
The FDA usually follows the panel's advice.
HRA Pharma, which already sells the pill in France, Britain and Germany, is hoping to market ulipristal in the United States under the name "Ella."
"Ella is an emergency contraceptive" to prevent pregnancy "following unprotected intercourse or a known or suspected contraceptive failure, the FDA said in a statement.
The drug, which can be used to end a pregnancy up to five days after a sexual encounter, "is not intended for routine use as a contraceptive," it said.
FDA staff looked at data for ulipristal that included 4,771 women who took the drug, including 2,764 that took the 30 milligram tablet that HRA Pharma hopes to sell in the United States.
"No deaths occurred and no unexpected adverse outcomes were observed in the clinical development program," read the FDA staff report.
"The most common adverse reactions were nausea, headache, dysmenorrhea (uterine pain), abdominal pain, fatigue, and dizziness."
The few serious side effects, such as a kidney infection and a ruptured cyst, seem to have been unrelated to treatment, the report said.
However data on the outcome of pregnancies "after EC (emergency contraceptive) failure with ulipristal were too limited to draw any definitive conclusions regarding the effect of ulipristal on an established pregnancy or fetal development."