WASHINGTON – An estimated 100,000 bottles labeled as the cholesterol-lowering medicine Lipitor are being recalled because they contain counterfeit pills, the Food and Drug Administration warned Friday.

The FDA said the fake pills were discovered after some health complaints, but would not elaborate because a criminal investigation is under way.

Lipitor users should immediately check their bottles to see if they have the fake version, which could pose a potentially significant health risk because the counterfeit pills will not lower cholesterol, the FDA said.

The recall covers original 90-pill bottles. To spot the fake version, look for the words “Repackaged by MED-PRO Inc., Lexington, Neb.” on the lower left corner of bottles that bear the following lot numbers:

. 20722V, expiration 09-2004

. 04132V, expiration 01-2004

. 16942V, expiration 09-2004

Patients who have those recalled bottles should not take the pills but return them to the pharmacy where they were bought.