PFIZER HAS ISSUED a voluntary recall of about one million packs of certain birth control pills which could leave women without adequate contraception.

The Lo/Ovral 28 packs, as well as Norgestral and another generic version could have been packaged incorrectly leading to an increased risk of unplanned pregnancies.

The pills are packaged in blister packs containing 28 tablets – 21 of which contain active ingredients and seven which are inert. To ensure effective contraceptive, they must be taken in the correct order.

The pharmaceutical giant said that there may be an issue with the way the pills were packaged, meaning the inactive or placebo pill may be out-of-order in some packs.

In a statement, the company 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.”

Corrective action has now been taken, Pfizer added. The Food and Drug Administration in the US has also been notified.

Although the recall concerns up to one million packs, the manufacturer believes only about 30 packs have been affected by the mistake.

Because of our high quality standards, should we identify even one package that does not meet our high standards, we will voluntarily recall the entire lot.”

“Therefore, we have voluntarily recalled the 28 lots – which is approximately 1 million packs – to ensure that any possibly impacted product is removed from pharmacy shelves – and women who use the product are alerted.”

According to the Wall Street Journal, the mistake was spotted after a women taking one of the incorrectly packaged pills noticed that there was a pink tablet in the space where a white one should have been.

Hundreds of thousands of women in the US use Lo/Ovral, Norgestral and and Ethinyl Estradiol (the generic version) tablets.