Health advocacy group Breast Cancer Action said Wednesday its campaign against Eli Lilly and Co.’s animal growth hormone won’t be seen in Indianapolis after it couldn’t find a billboard company to carry the message.

The message, “Eli Lilly is making us sick. Tell them to stop,” was rejected by about 10 billboard companies in Indianapolis, said Angela Wall, a spokeswoman for the San Francisco-based not-for-profit.

Clear Channel Outdoor Advertising, Lamar Outdoor Advertising and CBS were among the companies that rebuffed the group, she said.

“Short of a face-to-face conversation with them, a billboard would be a way for us to have that virtual face-to-face conversation with" Lilly officials, she said.

Lilly markets Posilac, a recombinant bovine growth hormone—or rBGH—used to boost cows’ milk production. Breast Cancer Action contends the hormone has been linked to cancer in humans. Lilly acquired the rGBH business from St. Louis-based Monsanto in 2008 for $300 million.

Breast Cancer Action’s “Milking Cancer” campaign demands Lilly stop manufacturing the artificial hormone.

Joan Todd, a spokeswoman for the Indianapolis-based pharmaceutical firm, said the hormone has proven to be safe. The U.S. Food and Drug Administration approved its use in 1993.

“When we’ve offered to sit down with [Breast Cancer Action] and go over the science, they’ve rejected the opportunity,” Todd said.

Wall, with Breast Cancer Action, argued that they declined the opportunity because Lilly refused to “open the books” on the hormone.

Billboard companies, meanwhile, overwhelmingly declined its message because of it was “too political,” she said.

Officials of a few of the billboard companies Breast Cancer Action approached could not be immediately reached for comment.

But Bruce Bryant, president of locally based Promotus Advertising, understands their tentativeness.

“With a statement that broad, where it could be damaging to Lilly as a second party without factual evidence presented, could be inflammatory,” he said. “If you’re making a claim against another company, the facts have to be presented.”