What: Shares of Herbalife Ltd. (NYSE:HLF) were up 16% at 1:40 p.m. Thursday after the nutrition supplement specialist announced better-than-expected second-quarter results.

So what: Quarterly revenue fell 11% year over year to $1.16 billion, albeit primarily due to foreign exchange headwinds. On a currency-neutral basis, Herbalife's revenue climbed 1%. Most notably, sales in China skyrocketed 39% year over year to $236.7 million, more than offsetting declines including foreign exchange in every other region. Even so, that translated to a 25.3% decline in adjusted net income to $105.6 million, and -- thanks to share repurchases -- a more modest 20% drop in adjusted net income per diluted share to $1.24. Meanwhile, cash flow from operations rose 26% year over year to $197.6 million. 

Analysts, on average, were expecting revenue of $1.14 billion, and lower adjusted earnings of only $1.11 per share.

"The second quarter continued the improving trends we saw in the previous quarter in terms of sales volumes and key sales leader metrics," explained HerbaLife CEO Michael Johnson, "and we believe we will see these positive trends continue through the second half of the year."

Now what: For the current quarter, Herbalife provided guidance for net sales to fall in the range of 10% to 7% including currencies, and adjusted earnings per diluted share in the range of $1.00 to $1.10. Analysts were anticipating third-quarter revenue would decline slightly less at 6.9%, and result in earnings near the bottom end of that range at $1.01 per share.

For the full year 2015, Herbalife expects revenue to decline 9.5% to 6.5% including currencies, which should lead to earnings per diluted share of $4.50 to $4.70. The latter is an increase from Herbalife's previous guidance range for EPS of $4.30 to $4.60. Wall Street's models were less optimistic, calling for full-year earnings of $4.51 per share on an 8.5% decline in revenue.

This was a solid report from Herbalife, especially considering currency headwinds should prove temporary over the long term. In the end, while I'm still content watching Herbalife's progress from the sidelines given its ongoing battle with activist investor Bill Ackman, I can't blame shareholders for celebrating today.