* FDA objects to Latisse website

* Company downplayed risks, FDA says

* Allergan says working to address concerns (Adds FDA and company comments, byline, share price)

WASHINGTON, Sept 16 (Reuters) - An Allergan Inc AGN.N website for a drug to lengthen eyelashes downplayed potential side effects such as redness and changes in eye color, U.S. health officials said in a letter released on Wednesday.

The website and other promotional material developed by Allergan “are misleading because they omit and minimize risks associated with Latisse,” the Food and Drug Administration said in a Sept. 10 letter to the company.

Latisse is a once-a-day prescription drug approved in December 2008 for lengthening and thickening eyelashes.

The FDA said certain pages on a Latisse website for consumers failed to mention risks such as a bacterial infection if the drug or applicators become contaminated. The web pages also minimized eye redness and itching because they suggested those conditions were not associated with allergic reactions related to the treatment, the FDA said.

Allergan’s website also “misleadingly suggests that only ‘similar’ medications have been associated with the risk of increased iris pigmentation,” which causes eye color to become more brown, the agency said.

The FDA asked Allergan to immediately stop using the materials.

The company is “working closely with the FDA to address all their concerns,” Allergan spokeswoman Heather Katt said.

One set of promotional material that drew FDA objections, an exhibit that described the evolution of lash enhancers, is no longer being used, Katt said.

Allergan, maker of wrinkle-fighting injection Botox, has forecast peak sales for Latisse topping $500 million a year.

Allergan shares gained 2.6 percent to close at $58.55 Wednesday on the New York Stock Exchange. (Reporting by Lisa Richwine; Editing by Gary Hill and Tim Dobbyn)