The Web site of Allergan Inc.'s (AGN) Latisse is misleading because it suggests the company's eyelash thickener is more safe than proven, federal regulators said on Wednesday.

In a letter to Allergan dated Sept. 10, the U.S. Food and Drug Administration said the company's Web site omits information about how people using Latisse are at risk for contracting bacterial keratitis, which can be blinding. The letter was posted on the FDA's Web site Wednesday.

Representatives for Allergan, based in Irvine, Calif., weren't immediately available to comment.

Latisse was approved by the FDA in December. It can increase the length, thickness and darkness of eyelashes by using a drug the company created to treat glaucoma. The FDA says Allergan's Web site and other promotional material for the product omits risk information. For instance, the promotional material doesn't mention that Latisse may cause hair to grow in areas other than the eye if it comes in repeated contact with the skin.

The FDA wants the company to correct the material. Allergan has until Sept. 24 to respond.

Shares of Allergan traded recently at $58.78, up 3%.

-By Jared A. Favole, Dow Jones Newswires; 202-862-9207; jared.favole@dowjones.com