A short seller attacking Valeant Pharmaceuticals International Inc. VRX, -15.90% has pulled back on hints he would unleash new bombshell revelations Monday about the drug company.

Related: Ackman says Valeant regulatory compliance no worse than rest of pharma industry

Andrew Left, who heads short-selling research firm Citron Research, said Sunday in an interview with The Wall Street Journal that investors shouldn’t “expect anything earth-shattering” when he issues a new report on Canada’s Valeant on Monday. He said he plans to update his view of the company, including with comments about the company’s “corporate culture.” Short sellers wager against stocks.

Left had tweeted Friday that he planned a new report on Valeant on Monday, following his Oct. 21 report that accused the company of using specialty pharmacies for “phantom sales” to inflate its financial results. In the tweet Friday, he said Citron would “update full story,” adding: “Dirtier than anyone has reported!!”

On Sunday, Left said didn’t have plans for further major allegations against Valeant, after having consulted with lawyers. His lawyers asked him how sure he was about what he had in mind to publish, on a scale of one to 10, and he was only at “eight,” he said. Left stressed he stood by his initial allegations.

Read an expanded version of this article at WSJ.com.