Bill Ackman calls out Herbalife after the company cuts sales outlook

• Herbalife shares dropped Monday after the company lowered its sales outlook for the second quarter.
• Hedge fund manager and long-time critic of the supplement company responded to the move by Herbalife.
• Ackman wants Herbalife to explain recent insider sales before this guidance update and also wants clarification on reports of recent executive departures.

After Herbalife lowered its sales guidance Monday, blaming disruptions caused by new FTC guidelines, hedge-fund manager and long-time company critic Bill Ackman seized on the announcement with a statement of his own.

"On May 4th Herbalife raised guidance driving the stock to new highs. Insiders including [CEO Michael] Johnson sold their stock and options. Fewer than three weeks after the stock sales, the company is now lowering guidance, somehow claiming that it is surprised by reduced volumes the first month the FTC settlement takes effect," the hedge-fund manager said in a statement emailed to CNBC.

CNBC's Scott Wapner reported Sunday evening that Herbalife would be lowering its sales guidance for the second quarter. Herbalife now expects revenue to be 1.5 percent lower than prior estimates, with a key sales metric known as volume points expected to be 3 percent below its earlier view. Earnings per share were actually increased for the quarter and the full year. The new FTC regulations went into effect in recent weeks.

"We also recently learned that Mark Friedman, the company's general counsel and the only signatory of the settlement agreement with the FTC, and other top executives have left the company. Remarkably Herbalife has yet to disclose, let alone explain the reasons behind these departures," the Ackman statement continued.

An Herbalife spokesperson declined to comment on either Ackman's statement or Friedman's current employment status.

On May 23rd, China Securities Journal reported that the head of Herbalife's China operations had abruptly left the company after a 10-year career there. No press releases from the company in May or June discusses executive departures and no news was disclosed to the SEC.

Despite these events and Ackman's long-held short position, Herbalife shares neared an all-time high last week. The stock dropped more than 6 percent during trading Monday.

---With reporting by Tae Kim