Pfizer is recalling about a million packets of birth control pills in the United States because they may not contain enough contraceptive to prevent pregnancy.
"As a result of this packaging error, the daily regimen for these oral contraceptives may be incorrect and could leave women without adequate contraception, and at risk for unintended pregnancy," according to a Pfizer statement on the U.S. Food and Drug Administration website.
Pfizer found that some packets of the drugs had too many active tablets, while others had too few.
The drugmaker said the issue involved 14 lots of Lo/Ovral-28 tablets and 14 lots of Norgestrel and Ethinyl Estradiol tablets.
The pills were manufactured by Pfizer and marketed by Akrimax Pharmaceuticals and shipped to warehouses, clinics and retail pharmacies nationwide, the company said.