Herbalife shares soared on Tuesday after the company posted quarterly earnings and revenue that beat Wall Street's expectations and raised its full-year guidance.
The stock jumped 16 percent in extended trading following the results. (Click here to see where the stock is trading now.)
The embattled nutrition and supplement company—a frequent target of activist investor Bill Ackman—posted adjusted first-quarter earnings of $1.29 per share, down from $1.50 per share in the year-earlier period. It reported $1.11 billion in revenue, down 12 percent from the previous year on the negative effect of a stronger U.S. dollar.
Herbalife increased its full fiscal 2015 adjusted profit outlook to a range of $4.30 to $4.60 per share. For the year, the company expects a currency headwind of about $1.26 per diluted share.
"We remain confident that we are building a stable foundation for volume and sales growth," said Herbalife CEO Michael Johnson in a release.
Wall Street expected the company to post quarterly profits of $1 per share and revenue of $1.09 billion, according to a Thomson Reuters consensus estimate.
Excluding foreign exchange, the company's total sales rose 4 percent year-over-year.
Herbalife's China business surged in the quarter to sales of $164.2 million including foreign exchange, up 21 percent from the previous year. The North America business declined 9 percent year-over-year.
Its largest revenue segment in the quarter, the Asia Pacific excluding China, fell 13 percent including foreign exchange.
Herbalife has recently faced scrutiny as federal law enforcement agencies have inquired about its business practices.
The company said its guidance does not include "legal and advisory" costs related to "challenges to the company's business model," including a Federal Trade Commission probe.
Herbalife's feud with Ackman, who heavily shorts the company's stock, has long been a sore spot.
"I think what you'll see [from the earnings] is a continued deterioration in the fundamental performance of the business. The government may do nothing, but I think the business goes away anyway," Ackman told CNBC on Monday.
In late March, Ackman said that shutting down the company, which he has described as a pyramid scheme, is "one of the most important things" he can do.
Speaking at a meeting of the Council of Institutional Investors in Washington, Ackman said again that Herbalife has caused "enormous harm to a very vulnerable population" by targeting undocumented Latinos in the United States and other poor people.
Herbalife has repeatedly denied Ackman's claims against it.
"Bill Ackman has been engaged in a nearly three-year effort to drive down Herbalife's stock in order to enrich himself and his investors. There is reportedly an ongoing federal criminal investigation into his campaign against Herbalife for stock manipulation and law enforcement and regulators have recently sought information from Herbalife and others relating to that investigation as well as trading in Herbalife shares and allegations about our business practices," Alan Hoffman, a Herbalife spokesman, told CNBC last month. "We are cooperating with these requests for information, remain confident in the integrity of our business practices, and are hopeful Ackman's long-term campaign of distortion will be found to be illegal."
The company's stock has risen about 5 percent so far this year, but it has still dropped more than 30 percent in the last 12 months.
—CNBC's Scott Wapner and Reuters contributed to this report.