Following a packaging error affecting birth-control pills, Pfizer has issued a one-million pack recall and warned women in the United States who have been taking the medication during the last several months to “…consult with your physician and begin using a nonhormonal barrier method immediately.”

Lo/Ovral-28 (norgestrel and ethinyl estradiol) and norgestrel and ethinyl estradiol tablets, the generic version of its birth-control pill, are manufactured and packaged by Pfizer, commercialized by Akrimax Rx Products, and labeled under the Akrimax Pharmaceuticals brand. Both products may have been affected by a packaging error in which the placebo or inactive pill was placed incorrectly in some packs. The products are packaged in blister packs that contain 21 tablets of active ingredients and seven placebo tablets, but it is the order in which the tablets are taken that leads to correct dosing of the medication—an important factor in avoiding the risks of unwanted pregnancy. At press time, there was very limited information on the Akrimax website regarding the recall.

Although Pfizer indicates, based on an internal assessment, that 30 packs may have received an inexact count or inactive tablet, it has recalled 28 lots accounting for one million packs to remove any product that could have been affected by the error. In a press statement, Pfizer said, “We understand that this news can be very concerning and confusing for any woman who takes birth control pills to protect against unintended pregnancies.”